Gestational Diabetes and Breastfeeding: Research References

by KMom

Copyright 1998-1999 KMom@Vireday.Com. All rights reserved.

DISCLAIMER: The information on this website is not intended and should not be construed as medical advice. Consult your health provider. It should be re-emphasized that nothing herein should be considered medical advice.



Purpose of This Websection

These are the medical study references for the websection on Gestational Diabetes and Breastfeeding: A Special Relationship. The list of references was so long it had to have its own file, unlike in most FAQ sections on this site. Many more references were used than could be cited due to length considerations.

The following listings represent some of the most important studies used to summarize the benefits of breastfeeding, considerations for breastfeeding and diabetes, common sources of interference in breastfeeding, general breastfeeding resources, etc. A significant amount of detail was included for certain studies, especially those on particularly controversial topics, or those where a closer look at the data reveal important questions. This makes some entries rather long, but hopefully will help the reader clarify issues or determine which studies would be most important to look up themselves.

Do be careful how you draw conclusions from medical research. Don't be too reverent; even medical research is subject to biases and sweeping generalizations and misjudgments. On the other hand, turn the same eye of doubt and questioning on claims of 'alternative' medical views. Whenever possible, review not just a few studies but a broad spectrum of studies, pro and con. It is the nature of medical research to have conflicting information and strong differences of opinion. Remember also that medical treatment evolves over time; procedures and approaches that used to be well-accepted are now totally discredited and unused, while new approaches may offer vast improvement in prognosis or might be found eventually to cause more harm than good. Take an overall, long-sighted view, and look carefully without jumping to preliminary conclusions.


Reminder of the purpose of the GD and Breastfeeding section:

The GD and Breastfeeding websection is an introduction to some of the main issues that surround the establishment of breastfeeding after a gd pregnancy. However, it must be noted that many protocols regarding management of breastfeeding and treatment of infants of gd pregnancies differ from provider to provider and between institutions. Also, these issues involve protocols that change over time. It is important to remember this when reading this FAQ, and that YOUR provider's assessment of your situation may differ. NONE of this should be considered medical advice, just a summary of the most common treatment protocols, recent research and its implications, and a brief review of some of the controversies.


Breastfeeding Resources

Websites and Organizations

The Breastfeeding Advocacy Page (

Extensive discussion and documentation on the many benefits of breastmilk. Excellent resource, with many medical references and studies examined. One of Kmom's favorites!

Breastfeeding.Com (

Superb site devoted to helping mothers nurse. Usual advocacy information, but its best value lies in its extensive photos of babies nursing in various positions, even video clips of how to do the various positions (including the much-neglected football hold!). Extensive photography of nursing babies, including twins, tandem nursing (toddler and newborn), multiethnic nursing mothers, etc., plus lots of beautiful artwork of nursing mothers from ancient to modern art.

The Breastfeeding Helpline (900) 448-7475, ext. 55 ($1.99 per minute/avg 5 minutes; some sources list ext. 65 instead)

Recorded information available, counselors available during certain hours (La Leche League Service) .

CARE NW (Care and Advice on Reproductive Exposures) 1-900-225-CARE ($3 first minute, $2 for each additional)

This *INVALUABLE* service provides information on the effects of drugs and other exposures on the developing fetus and during lactation. If you are not sure about the safety of a certain drug or chemical exposure during pregnancy or during breastfeeding, they will research it for you. They often have access to more complete information than your physician. Their services were formerly available only to residents of the Pacific Northwest, USA, but they have now opened up to service elsewhere through the use of the 900 number.

Hale's Medications and Mother's Milk (

THE most reliable source for up-to-date information about medications while nursing is this book. It is updated every year; every medical library and pediatrician should have it. Unfortunately, not all do. A smaller version of the book is available at the website plus information about the full book. If you really need to access this book, call a large local hospital and ask for the medical librarian. If they do not have this book ask if they can borrow it from another hospital or library. If not, they can probably photocopy the page of the medication in question for you and mail it to your local hospital. Most hospitals do this for free, but some may charge a small amount.

La Leche League International 1-800-LA-LECHE 1-847-519-7730 ( )

Excellent resource for information/support for nursing. Call to find the nearest meeting, to get in contact with a volunteer leader for questions, or to get a referral to a good lactation consultant. Also check out the web site! The best time to start attending meetings is BEFORE you deliver. Some women are afraid LLL is too radical for them; most do not find it so, but quality depends on the local leadership. However, the philosophy is "take what you need and leave the rest behind," so if you don't agree with something, ignore that recommendation. Truly an exceptional resource. Also offers many fine pamphlets on nursing-related topics/concerns.

Medela, Inc. Breastfeeding Tips and Products 1-800-TELL-YOU (835-5968) ( )

Call for Breastfeeding Advice Booklet that gives hints on breastfeeding, as well as offers several Medela products. Some products that might assist a large woman in particular are the Extra Large Glass Breastshield Kit (#610.7041) and a 15-minute video on Breastfeeding Your Baby - Positioning (#610V010). This excellent short presentation on positioning includes the football hold, which often works better for women who are extremely well-endowed, as well as more traditional holds. This is often not covered in other books or videos on the subject, so this is an extremely valuable asset to a large woman. A longer version of this video is available but the positioning section is all that's really needed for most people. A spanish version can also be ordered.

Nursing Mother's Association of Australia ( )

A La Leche League-type organization for Australia; anecdotal reports Kmom has heard have been very positive. Contact them for support for nursing or for consultation if you encounter problems.

parent-l mailing list ( )

An extensive, high-volume mailing list designed to support breastfeeding and parenting the nursing child. There is an emphasis on extended breastfeeding and attachment parenting. To subscribe to the single message mode simply send a message with 'subscribe' in the body of the message.

Pumping Advice/Story (what looks like a space is really an underline in the URL)

Owner of the BigMom's mailing list (who also had insulin-dependent gd) details her story of breastfeeding difficulties at first, pumping travails, how she stuck it out, pumping advice to others, etc. (the space in the URL above is really an underline).

Rx List ( )

Provides free comprehensive information about 4000 commonly prescribed drugs. However, if this list is like the Physician's Desk Reference, it is overly conservative because of liability fears, and may list certain drugs as incompatible with nursing when under certain circumstances they might be ok. Use this list as an adjunct resource but not as your sole resource when researching drugs and lactation.

Working Cow Website (

More information about being a nursing mom while working outside the home, pumping advice, etc.

Breastfeeding After a Breast Reduction ( )

Information about breastfeeding after having a breast reduction operation.


Nursing Books

These are the best nursing books, in Kmom's opinion;Your Mileage May Vary! You can find these books through:

The Nursing Mother's Companion, Kathleen Huggins, 4th Revised Edition, c. 1999.

By far the easiest-to-use and most practical of nursing guides. Pack this one in your hospital bag! Especially useful is the quick-reference Survival Guide for the First Weeks--much easier to use for trouble-shooting if you have any questions or problems. Has a few references to the problems of larger breasts, and actually shows some in a section on the different sizes and shapes of breasts. One of the only nursing books to address this!

The Womanly Art of Breastfeeding, La Leche League International, 6th Revised Edition, c. 1997.

Classic text on breastfeeding, very well-done--but does not address the issues that can challenge some large-breasted women. Barely addresses the football hold, and some women find it very preachy. Still worth reading, however, and the section on medical benefits of breastfeeding is superb---a must-read.

So That's What They're For! Breastfeeding Basics. Janet Tamaro, c. 1996.

A more humurous approach to breastfeeding, but still full of useful information. A great book to get if you are not sure whether you want to nurse or not, or if you think you should but are not really crazy about the idea. Good for spouses too. Good book, but don't make it your only nursing manual; use it in tandem with another nursing manual like Nursing Mother's Companion or Womanly Art of Breastfeeding. Contains a few sizist remarks but still overall a good asset.



Breastfeeding Helps GD Babies and Moms

Cordero, L et al. Management of Infants of Diabetic Mothers. Arch Pediatr Adolesc Med. March 1998. 152(3):249-254.

Examined the clinical outcome of infants born to mothers with gd and mothers with pre-existing type one diabetes. Experimented with routine care and normal feedings for these babies (vs. the usual hospital policy of automatic admission to the NICU for observation, testing, and supplementation). Found that most gd babies assigned to routine care did fine, but that breastfed babies had fewer routine care failures that resulted in the baby having to be admitted to the NICU. States that "breastfeeding among women with GDM and IDDM should be encouraged" but does note that many of the routine policies in the past for babies of diabetic mothers (extended admission to the NICU, lapse time to the first breastfeeding, lack of breastpumps and proactive encouragement and assistance) has made bfing rates lower. Actually brags about its 37% rate of exclusively or partially breastfed infants as a satisfactory measure of its 'success'! [Seems like if its lactation program and proactive encouragement were really satisfactory, it ought to have a much higher rate than 37%. Demonstrates that if this is considered high, bfing rates among diabetics must have been particularly pitiful in the past and attests to the many obstacles some diabetic mothers can face.]

Yang, JQ et al. Breastfeeding in Reducing Regular Insulin Requirement in Postpartum for Insulin-Dependent Diabetes Mellitus and Gestational Diabetes Mellitus. Chung Hua Fu Chan Ko Tsa Chih. March 1994. 29(3):135-137.

Looked at the insulin requirement in IDDM and gd moms immediately post-partum. Found a significant decrease of regular insulin (RI) requirement among breastfeeding mothers overall. Among gd mothers who breastfed, insulin requirements disappeared almost immediately, while those that did not breastfeed often required further insulin for 4-7 days postpartum. However, the sample used is extremely small and limits the power of the study. The authors concluded, "BF can reduce the RI requirement of IDDM and GDM mothers in the postpartum period. It is thought that more energy is needed in the process of producing milk, and serum glucose is the main substance for lactose synthesis, thus blood glucose level of BF mother is decreased, and so is the RI requirement. Therefore, mothers with diabetes mellitus are encouraged to breast feed their babies."

Wallensteen, M et al. Acute C-Peptide, Insulin, and Branched Chain Amino Acid Response to Feeding in Formula and Breast Fed Infants. Acta Paediatr Scand. February 1991. 80(2):143-148.

Very technical article detailing c-peptides, branched chain amino acids, and fasting and post-meal bG response in both breastfed and formula-fed infants (small sample). The authors summarize at the end, "these results confirm that in formula-fed infants the insulin response to a meal is enhanced compared to that in breast-fed infants. The finding of similar blood glucose values in the two groups may also indicate an insulin resistance in the formula-fed infants following a meal." In other words, f-fed infants produced more insulin in response to feeding than bfed infants did, yet their blood sugar was the same, implying that insulin resistance was occurring. This study showed that in this situation, formula-fed infants had to produce more insulin in order to get the same blood sugar reading, which might indicate the possible start of a pattern of developing insulin resistance, which could possibly have significant effects later in life. The sample size was small and the implications speculative, but it's a potentially significant finding.

Baur, LA et al. The Fatty Acid Composition of Skeletal Muscle Membrane Phospholipid: Its Relationship with the Type of Feeding and Plasma Glucose Levels in Young Children. Metabolism. January 1998. 47(1):106-112.

Extremely technical article about Long-Chain PolyUnsaturated Fatty Acids (LCPUFAs) and breastfeeding. The important point is that low levels of these LCPUFAs are associated with insulin resistance and obesity in adults. "The results of this study show that (1) breast-feeding increases LCPUFA levels in skeletal muscle membrane and (2) early development of relatively higher levels of LCPUFAs in the phospholipid of skeletal muscle, influenced both by type of feeding and by genetic predisposition, is associated with lower fasting plasma glucose. Early changes in skeletal muscle membrane phospholipid FA saturation may play a role in the subsequent development of diseases associated with insulin resistance."

Meyers-Seifer, C. and Vohr, B. Lipid Levels in Former Gestational Diabetic Mothers. Diabetes Care. 19(12):1351-6. December 1996.

Found that "at 5-6 years postpartum, former gestational diabetic mothers demonstrate changes in lipid levels that differ from control mothers and that specific lipids correlate with cardiovascular risk factors." In particular, the study found increased triglyceride levels, total cholesterol levels, and LDL cholesterol levels in gd mothers, as well as increased glucose levels and systolic blood pressure. However, the abnormal levels were not related directly to fasting glucose levels during pregnancy or need for insulin therapy. Study notes that underlying inherited genetic predisposition to dyslipidemia may be a factor, as well as lifestyle differences such as diet and exercise status, and that the role of these other factors needs to be investigated more thoroughly. .

Kjos, SL et al. The Effect of Lactation on Glucose and Lipid Metabolism in Women with Recent Gestational Diabetes. Obstetrics and Gynecology. 82(3):451-5. September 1993.

Landmark study that shows that even after only 4-12 weeks of breastfeeding, gd moms that were bfing had lower fasting glucose and better HDL cholesterol levels than gd mom who did not bf. Also found that women who did not bf developed early postpartum diabetes at *twice* the rate of those who did bf, both in the diet-treated group and the group that needed insulin in pregnancy. "Lactation, even for a short duration, has a beneficial effect on glucose and lipid metabolism in women with gestational diabetes. Breast-feeding may offer a practical, low-cost intervention that helps reduce or delay the risk of subsequent diabetes in women with prior gestational diabetes." And this studied ONLY 4-12 weeks of breastfeeding.

Pettit, DJ et al. Breastfeeding and Incidence of Non-Insulin-Dependent Diabetes Mellitus in Pima Indians. Lancet. July 19, 1997. 350(9072):166-168.

Examined the association between NIDDM and bfing in a population with a high prevalence of NIDDM. Studied the effects of infant feeding methods (for the first 2 months only). Those who had formula only had somewhat higher weights than those who had been partially or fully breastfed. Those who had been exclusively bfed for 2 months had significantly lower rates of NIDDM in all age-groups. "The odds ratio for NIDDM in exclusively breastfed people, compared with those exclusively bottlefed, was .41" (less than half). "Exclusive breastfeeding for the first 2 months of life is associated with a significantly lower rate of NIDDM in Pima Indians." The weaknesses of the study is that it is done in a population known for its ultrahigh rates of diabetes; it is unknown whether these findings would apply to other groups. Also, the number of people exclusively bfed for at least 2 months was not extremely high (144/720, about 20%) which weakens the power of the conclusions. However, it should also be noted that the study only examined those exclusively bfed for *2* months, which may show a lower overall effect than if infants exclusively bfed much longer were compared. [The American Academy of Pediatrics now recommends that infants be exclusively breastfed for at *least* one year, and longer if desired.]


Protective Effect of Breastfeeding

*Extensive references on this subject exist elsewhere; there is no need to duplicate these here. The following represent only a few of the many possible references out there.

Scariati P.D. et al., A Longitudinal Analysis of Infant Morbidity and The Extent of Breastfeeding in the United States. Pediatrics. June, 1997. 99(6):E5.

Examined the rates of diarrhea and ear infections in US infants, adjusting for several confounding effects and examining the effect of how much breastmilk was consumed, unlike many earlier studies. The authors found that "The risk of developing either diarrhea or ear infection increased as the amount of breast milk an infant received decreased...Breastfeeding protects US infants against the development of diarrhea and ear infection. Breastfeeding does not have to be exclusive to confer this benefit...[but] the more breast milk an infants receives in the first 6 months of life, the less likely that he or she will develop diarrhea or ear infection."

Newman, Jack (M.D.) How Breast Milk Protects Newborns. Can be found at (please note that what looks like a space in that URL is actually an underline)

Excellent short article describing in technical but still readable terms exactly how breastmilk protects babies immunologically. Highly recommended.

Birch, EE et al. Visual Acuity and the Essentiality of Docosahexaenoic Acid and Arachidonic Acid in the Diet of Term Infants. Pediatr Res. August 1998. 44(2):201-9.

Compared the visual acuity of infants fed formula fortified with DHA or DHA/AA for the first 4 months of life to that of infants fed non-fortified formula and also to breastfed infants (in their words, the 'gold standard group'). Found that infants fed the non-DHA fortified formula had significantly different visual acuity measures compared to either the DHA-fortified formula infants and the breastfed infants, who were 'similar'. "Early dietary intake of preformed DHA and AA appears necessary for optimal development of the brain and eye of the human infant." [Note: Most USA formulas are not currently fortified with DHA. Manufacturers are currently debating doing this, but how and how much are being debated; the addition of DHA does not appear imminent.]


General Breastfeeding and Diabetes-Breastfeeding Resources

Engelking, Cynthia and Judith Page-Lieberman. Maternal Diabetes and Diabetes in Young Children: Their Relationship to Breastfeeding. Lactation Consultant Series, La Leche League International. Avery Publishing Group, Garden City Park, NY. 1986. Available from

Excellent review of the concerns of a diabetic pregnancy and its impact on breastfeeding practices. Good overview of the possible complications of diabetic pregnancy, though more relevant to type I pregnancies than gd. Covers type I, II, and GD pregnancies, as well as development of type I diabetes in young children who might still be breastfeeding. Written in 1986 so its information is a bit dated on gd, but still a valuable resource.

Mohrbacher, Nancy and Julie Stock. The Breastfeeding Answer Book. La Leche League International. 1997 Revised Edition. Available from

The ULTIMATE reference for up-to-date information about breastfeeding and medical issues. Extensively referenced and researched. Very expensive book to purchase for yourself but many local LLL chapters will have this book available in their lending libraries, or one of the Leaders will.

Asselin, BL and RA Lawrence. Maternal Disease as a Consideration in Lactation Management. Clinics in Perinatology. 14(1):71-87. March 1987.

Treatise for OBs, perinatologists, pediatricians, and internists on how to handle lactation issues in women with chronic diseases such as diabetes (mostly type I), severe asthma, kidney disease, and chronic hypertension. Written by 2 doctors/medical school professors with great expertise in lactation issues; excellent resource for the medical professional. Most lay readers will find it a bit dense for their purposes, but a few may find it useful for ideas to share with their health provider about how to preserve breastfeeding in the face of chronic maternal disease.

Baumslag, Naomi M.D., and Dia L. Michels. Milk, Money, and Madness: The Culture and Politics of Breastfeeding. Westport, Connecticut: Bergin and Garvey. 1995.

Excellent (but highly inflammatory) book about cultural, economic, and political influences on breastfeeding and artificial substitutes (formula). Examines the history of artificial substitutes, the formula industry, and the socio-political influences on its production and use. An excellent source of nutritional and immunological breakdowns of breastmilk, has interesting summaries of breastfeeding research, and fascinating charts comparing human milk to the milk of other species.

Huggins, Kathleen. The Nursing Mother's Companion. 4th Revised Edition. Boston: Harvard Common Press. 1999.

By far the easiest-to-use and most practical of nursing guides. Pack this one in your hospital bag! Especially useful is the quick-reference Survival Guide for the First Weeks--much easier to use for trouble-shooting if you have any questions or problems. Has a few references to the problems of larger breasts, and actually shows some in a section on the different sizes and shapes of breasts. One of the only nursing books to address this!

La Leche League International. The Womanly Art of Breastfeeding. 6th Revised Edition. New York: Penguin Putnam Inc. (A Plume Book). 1997.

Classic text on breastfeeding, very well-done--but does not address the issues that can challenge some large-breasted women. Barely addresses the football hold, and some women find it very preachy. Still worth reading, however, and the section on medical benefits of breastfeeding is superb---a must-read.

Tamaro, Janet. So That's What They're For! Breastfeeding Basics. Holbrook, Massachusetts: Adams Media Corporation. 1996.

A more humurous approach to breastfeeding, but still full of useful information. A great book to get if you are not sure whether you want to nurse or not, or if you think you should but are not really crazy about the idea. Good for spouses too. Good book, but don't make it your only nursing manual; use it in tandem with another nursing manual like Nursing Mother's Companion or Womanly Art of Breastfeeding. Contains a few sizist remarks but still overall a good asset.


Things That Interfere With Breastfeeding

Blomquist, HK et al. Supplementary Feeding in the Maternity Ward Shortens the Duration of Breast Feeding. Acta Paediatr. November 1994. 83(11):1122-1126.

Feeding routines of a maternity unit and subsequent feeding patterns then of 521 infants were analyzed in a prospective study. 25% of the babies studied received supplementary feeds of human milk or formula by bottle on the third day, the indications for this being, among others, maternal diabetes or gestational diabetes. At 3 months, 65% were still being exclusively breastfed. However, of the ones who were not, risk factors included maternal age <25, maternal smoking, initial weight loss greater than 10%, and neonatal feeding. Babies given supplements in the maternity unit had 4x the risk of not being breastfed at 3 months than those babies not given supplements. "Thus the administration of supplementary donor's milk or formula during the early neonatal period was associated with an increased risk of a short duration of breast feeding, even after adjustment for a number of potential confounders."

Righard, L and Alade, MO. Breastfeeding and the Use of Pacifiers. Birth. June 1997. 24(2):116-120.

82 exclusively breastfeeding mother-infant pairs were followed up for 4 months to study the effect of pacifier use on breastfeeding duration. "The breastfeeding rate at 4 months was 91% in the nonpacifier group and 44% in the pacifier group (p = 0.03). An incorrect superficial nipple-sucking technique at the breast from the start combined with pacifier use resulted in early weaning in most cases. To promote successful breastfeeding and to reduce nursing problems, an incorrect sucking technique should be prevented or corrected, and the use of pacifiers should be avoided or restricted."

Cronenwett, L et al. Single Daily Bottle Use in the Early Weeks Postpartum and Breastfeeding Outcomes. Pediatrics. 1992. 990(5):760-66.

Found that "30% of mothers whose babies received bottles in the hospital reported severe breastfeeding problems, as compared with 14% of those whose babies did not."

Perez-Escamilla, R et al. The Association Between Cesarean Delivery and Breast-Feeding Outcomes Among Mexican Women. American Journal of Public Health. June 1996. 86(6):832-836.

Examined the impact of a c-section on the initiation and duration of breastfeeding in 2517 Mexican women. "Cesarean section was a risk factor for not initiating breast-feeding (odds ratio [OR]=0.64...) and for breast feeding for less than 1 month (OR=0.58...). It is desirable to provide additional breast-feeding support during the early postpartum period to women who deliver via cesarean sections."

Willis, CE and Livingsone, V. Infant Insufficient Milk Syndrome Associated with Maternal Postpartum Hemorrhage. Journal of Human Lactation. June 1995. 11(2):123-126.

Examines a possible association between 'insufficient milk syndrome' and maternal postpartum hemorrhage. Ten consecutive cases of this were identified. Maternal postpartum blood loss ranged from 500-1500 ml in 8 cases; in 2 cases, it was noted simply as 400++ and 200++ instead. 6 mothers experienced a significant drop of hemoglobin, and 2 had a big drop in blood pressure for >20 minutes. All infants were 'failing to thrive'. "These data serve to heighten awareness of insufficient milk syndrome as a potential consequence of postpartum hemorrhage. Early postpartum review of all breastfeeding mothers and infants is strongly encouraged."

Freed, GL et al. Pediatrician Involvement in Breast-Feeding Promotion: A National Study of Residents and Practitioners. Pediatrics. September 1995. 96(3 Pt 1):490-494.

"This study was designed to assess pediatricians' knowledge, attitudes, training, and activities related to breast-feeding promotion" through the use of a random survey mailing to pediatricians and pediatric residents (over a thousand responded). "Their clinical knowledge and experience did not suggest a high degree of competency." For example, a number were not aware of breastfeeding's protective effect against ear infections, and many recommended inappropriate breastfeeding termination or formula supplementation. "Only 64% of practitioners and 52% of residents knew that supplementing during the first few weeks of life may cause breast-feeding failure." For both groups, prior personal breastfeeding experience (themselves or their spouses) was a major determinant of knowledge and activity. "Residents reported that the breast-feeding instruction provided during training was primarily in lecture format, with limited clinical opportunities to practice skills needed to assist breast-feeding mothers...These results indicate that residency training does not adequately prepare pediatricians for their role in breast-feeding promotion. Improvements in residency training and innovative continuing education programs should be implemented to help pediatricians meet the needs of their breast-feeding patients."


Contraception, Breastfeeding, and GD

Kjos, SL. Contraception in Diabetic Women. Obstetrics and Gynecology Clinics of North America. 23(1): 243-258. March 1996.

Excellent overview of the concerns and considerations for contraception in diabetic women. Covers women with pre-existing diabetes before pregnancy as well as women who had gestational diabetes but does not lump them together for consideration. Has one brief mention only of breastfeeding considerations when prescribing oral contraceptives; certainly needs to cover more thoroughly the potential effects on milk supply and concerns about hormonal influence on infants. However, this is certainly not an unusual omission in this type of article. A very valuable resource in spite of this.

Kjos, SL et al. Contraception and the Risk of Type 2 Diabetes Mellitus in Latina Women with Prior Gestational Diabetes Mellitus. Journal of the American Medical Association. August 12, 1998. 280:533-538. Available for viewing at

Most recent research on the use of the progestin-only minipill and its relationship to the subsequent development of full-blown diabetes. Found that mini-pill users had nearly triple the risk of developing subsequent diabetes, while the standard low-dose combination pill seemed to be safe. However, the study concentrated mostly on Hispanic women, who have a much higher rate of development of diabetes anyhow, and many of the participants were also obese, which could affect the results as well. Although this is the first *large-scale* study to look at the effects of oral contraceptives on diabetes, the authors acknowledge that it's not clear how the results should be applied to other ethnic groups.


Breastfeeding and Obesity

Kramer, MS. Do Breastfeeding and Delayed Introduction of Solid Foods Protect Against Subsequent Obesity? Journal of Pediatrics. June 1981. 98(6):883-887.

Previous studies examining whether breastfeeding was protective against later obesity tended to find mixed results. This study faults previous studies for methodologic flaws (Type II error, confounding variables, and non-blinding) and conducted its own case-control study of 1172 adolescents. Raw data revealed a significantly elevated risk in 'overweight' subjects of not being breastfed. Delaying solid foods was found to be irrelevant. "We conclude that breast-feeding does protect against later obesity and attribute the conflicting results of previous studies to insufficient attention to methodologic standards."

Kramer, MS et al. Determinants of Weight and Adiposity in the First Year of Life. Journal of Pediatrics. January, 1985. 106(1):10-14.

Examined 462 full-term healthy infants in the first year of life. Examined the roles of various factors in 'adiposity' in the first year. Found that birth weight, duration of bfing, gender, etc. did influence BMI somewhat, though "the ability to preduct which babies will be heavy or obese during the first year is limited" [and Kmom doubts the value of such a task]. However, it did find that even after adjusting for confounding factors, breastfeeding did offer some protective effect against 'obesity'.

Strbak, V et al. Late Effects of Breast-Feeding and Early Weaning: Seven-Year Prospective Study in Children. Endocr Regul. June 1991. 25(1-2):53-57.

"The effect of breastfeeding on some clinical and thyroid function parameters was studied in a prospective longitudinal study from birth up to 7 years of age. At the ages 1-7 years, the obesity rates observed in children breast-fed for less than 3 months were substantially higher than in children who had been breast-fed over longer intervals." [Notes other findings but this is the relevant one here.]

Elliot, KG et al. Duration of Breastfeeding Associated with Obesity During Adolescence. Obes Res. November 1997. 5(6):538-541.

Examined the relationship between duration of breastfeeding and obesity in a white rural population where confounding factors of race was absent and socioeconomic status was expected to be minimal. When examined independently, <2 months of bfing WAS associated with adolescent obesity, but only in lower socioeconomic groups. But when sex, birthweight, and socioeconomic status was figured in as confounding variables, the association disappeared.

Dewey, KG et al. Breast-Fed Infants are Leaner than Formula-Fed Infants at 1 y of Age: The DARLING Study. American Journal of Clinical Nutrition. February 1993. 57(2):140-5.

Dewey, KG et al. Growth of Breast-Fed and Formula-Fed Infants from 0 to 18 Months: The DARLING Study. Pediatrics. June 1992. 89(6 Pt 1):1035-41.

Dewey, KG. Growth Characteristics of Breast-Fed Compared to Formula-Fed Infants. Biol Neonate. 1998. 74(2):94-105.

All three of these publications note essentially the same conclusion: that breast-fed infants tend to be leaner than their formula-fed counterparts. Contends that this is because breastfed infants tend to have a lower energy intake than formula-fed infants, and also a lower metabolic rate. Notes that evidence to date does not suggest that there are any adverse consequences associated with a lower intake or slower weight gain in breastfed babies, that in general breastfed infants have similar activity levels, head circumference, and less illness and perhaps enhanced cognitive development.

von Kries, R et al. Breast Feeding and Obesity: Cross Sectional Study. British Medical Journal. July 17, 1999. 319(7203):147-50.

9357 German children aged 5 and 6 were evaluated by parental questionnaire about early feeding, diet, and lifestyle factors, and heights/weights of the children were collected. 'Overweight' was defined as above the 90th percentile in Body Mass Index of all enrolled German children; 'Obesity' was defined as a BMI above the 97th percentile. "The prevalence of obesity in children who had never been breast fed was 4.5% as compared with 2.8% in breastfed children. A clear dose-response effect was identified for the duration of breast feeding on the prevalence of obesity: the prevalence was 3.8% for 2 months of exclusive breast feeding, 2.3% for 3-5 months, 1.7% for 6-12 months, and 0.8% for more than 12 months. Similar relations were found with the prevalence of being overweight." Even after adjusting for confounding factors, bfing was a significant protective factor against developing obesity (odds ratio 0.75) or being overweight (odds ratio 0.79). "In industrialized countries promoting prolonged breast feeding may help decrease the prevalence of obesity in childhood. Since obese children have a high risk of becoming obese adults, such preventive measures may eventually result in a reduction in the prevalence of cardiovascular diseases and other diseases related to obesity." (perhaps type II diabetes?)


Breastfeeding and Type I Diabetics: Lessons to be Learned

Ferris, AM et al. Lactation Outcome in Insulin-Dependent Diabetic Women. Journal of the American Dietetic Association. March 1988. 88(3): 317-322.

30 women with Type I Diabetes (IDDM) and 30 non-diabetic matched controls were studied in 1984 for 6 weeks. 16 of the IDDM mothers intended to breastfeed, 14 did not. Of the mothers who chose bfing, most had less severe stages of IDDM; none of the mothers with more advanced stages of IDDM chose to try to bf. In keeping with typical hospital interference of the early 80s, none of the bfing mothers, diabetic or controls, were able to room in with their babies, and nearly all received some supplementation. Babies were also routinely separated from their mothers, breastfeeding or bottlefeeding, and breastpumps were almost totally unavailable during the initial separation as well. IDDM mothers who wanted to bf basically did not get to start nursing until about 3 days after the birth; non-diabetic controls who wanted to bf got to start nursing within about 12 hours or so (although shorter, this is still far too long and reflects outmoded policies of that day. Babies should be nursed immediately after birth). Babies of IDDM pregnancies were placed in neonatal care units and given formula and other supplementation for about the first 3 days. IDDM babies were documented as receiving significantly more formula than controls, and the more formula that was given by day 2, the less breastfeeding persisted over time. IDDM mothers also experienced more problems with let-down, illness, fever, and mastitis, not surprising considering that they didn't get to nurse for 3 days postpartum and mostly did not have access to breastpumps either. Of the IDDM mothers who quit nursing, most cited irritability of the baby and poor suckling ability; likely caused by the significant amount of previous supplementation and problems with nipple confusion from bottle use. IDDM mothers who bfed needed more total calories; of the bfing IDDM mothers who chose to quit nursing, many consumed less calories (even while nursing) than those who kept nursing. IDDM mothers who bfed lost significantly more weight after the birth, and had much lower fasting glucose values (82 mg/dl vs. 120 mg/dl), despite higher caloric intakes and similar insulin dosages to those who did not nurse. Despite all the interference, breastfeeding rates were similar between IDDM mothers and non-diabetic controls at 6 weeks, an excellent testament to the dedication of these mothers in view of all the interference! Long-term bfing rates were not measured, but other studies have found lower rates of breastfeeding among diabetic mothers.

Ferris, AM et al. Perinatal Lactation Protocol and Outcome in Mothers With and Without Insulin-Dependent Diabetes Mellitus. American Journal of Clinical Nutrition. July 1993. 58(1):43-8

33 women with IDDM were compared with 33 matched control subjects and 11 reference subjects for 84 days postpartum. The 'control' mothers were matched for mode of delivery and other factors, since diabetic women have a notoriously high c-section rate (70% in this study!!!) which might affect lactation. 'Reference' women were those who had normal vaginal delivery with a minimum of intervention and medication. Women with IDDM spend significantly less time with their babies after delivery than the control subjects or reference subjects (they only saw their babies 19% of the time in the first 2 days!). IDDM babies were breastfed for the first time at about 26 hours postpartum on average, whereas the control subjects first breastfed at about 11 hours postpartum and the reference subjects at 4.6 hour pospartum (all very pitiful; babies should be nursed immediately after birth!). Once again, women in all groups were not encouraged to use pumps in the interim; this combined with the lack of breastfeeding contact with the baby after birth meant that the IDDM mothers' milk "came in" much later. More IDDM mothers also discontinued bfing within 42 days postpartum, probably because they used more formula supplementation and tended to nurse less frequently, and they also tended to perceive that their infants had more feeding problems as well (small wonder!). However, the study speculates that feeding problems are probably due to the 'reduced ability to respond' that some IDDM babies have, rather than the effects of significant separation, heavy-duty maternal medications during delivery, major formula supplementation and nipple confusion, and the common problem of jaundice. The study also blamed the IDDM group's greater use of formula, less frequent bfing, and earlier weaning on the diabetes, suggesting that "an adequate milk supply may never be produced by some women with IDDM." They acknowledged that early separation and supplementation etc. might have some effect on this, but that this "cannot explain the long-term differences in feeding behavior...throughout the course of lactation by the mothers with IDDM." (Ridiculous! Although poor blood sugar control CAN affect lactogenesis, the early separation and supplementation can and HAS been shown to influence later weaning and supplementation patterns in non-diabetic women too.)

Practice Points: Translating Research Into Practice. Preparing Pregnant Women with Diabetes for Special Breast-Feeding Challenges. Journal of the American Dietetic Association. June 1998. 98(6):648.

Offers practical tips on helping type I diabetics establish breastfeeding. Among other things, suggests a light snack before or during nursing, checking blood sugar levels before nursing, etc. Notes the 'Honeymoon Period", in which many type I moms experience a need for only about half of the insulin dosage needed in pregnancy, so careful adjustments of insulin and food intake must be done. Also notes that "studies show that the first 1 to 1.5 hours of life are critical for encouraging the baby to latch on to the nipple properly, which in turn stimulates milk production and helps mother and baby to bond. Women with type 1 diabetes sometimes face obstacles, however, in staying with their babies immediately after birth...A baby-friendly hospital makes providions for such separations and assists the mother in pumping and storing her milk, which aids in establishing a good milk supply and prevents engorgement. An eye dropper can be used to give the breast milk in the nursery, thus avoiding the introduction of formula and artificial nipples that can reduce the baby's interest in breast-feeding."


Breastfeeding and Type II Diabetes

Benz, J. Antidiabetic Agents and Lactation. Journal of Human Lactation. March 1992. 8(1):27-28.

"If the dose of insulin and adequate carbohydrate intake is ensured, most diabetic mothers taking insulin will be able to breastfeed satisfactoriy. Compared to the dose before pregnancy, the required insulin dose probably will be substantially reduced during breastfeeding. The American Academy of Pediatrics recommends tolbutamide as the preferred oral hypoglycemic agent during the breastfeeding period; however, the infant should be monitored closely for signs of jaundice. The mother should be monitored using a method specific for glucose, since lacturia may interfere with nonspecific methods of urine glucose measurement. It is important to monitor for ketones in the mother because acetone is excreted in breastmilk and may adversely affect the infant's liver."


PolyCystic Ovarian Syndrome, GD, and Nursing

*Please note that PCO, PCOS, PCOD etc. all refer to essentially the same condition. However, they are umbrella terms for a wide variety of symptoms and problems, and many PCO women are somewhat dissimilar in their presenting symptoms and disease effects. For more information, please see the websites as or

Anttila, L et al. Polycystic Ovaries in Women with Gestational Diabetes. Obstetrics and Gynecology. July 1998. 92(1):13-16.

Retrospectively examined 31 women with gd to 30 healthy controls matched by age and Body Mass Index (BMI). 14 women with gd had polycystic ovaries (44%) compared to only 2 control women (6%). No difference was found in BMI or in weight gain in pregnancy, nor in the observed mean birth weight of the infants between groups. "Polycystic ovaries were a common finding among women with GDM. The data suggest that women with PCO are at risk for developing GDM and should be screened accordingly.

Holte, J et al. High Prevalence of Polycystic Ovaries and Associated Clinical, Endocrine, and Metabolic Features in Women with Previous Gestational Diabetes Mellitus. Journal of Clinical Endocrinological Metabolism. April 1998. 83(4):1143-1150.

Examined 34 women with GDM and 36 controls with uncomplicated pregnancies. 41% of the gd women had polycystic ovaries, compared to 3% of the controls. GD women also had more hirsutism (excess body hair), irregular menstrual cycles, and higher BMI. When they sub-analyzed the gd mothers into 2 groups----those with polycystic ovaries and those without, the pco gd moms were younger, had a higher fat ratio, higher blood lipids, higher concentrations of androgen-type hormones, and a higher rate of pregnancy-induced hypertension (50% vs. 15%). "In conclusion...signs of polycystic ovary syndrome were much increased in women with a history of GDM. Compared with the women with normal ovaries and previous GDM, those with polycystic ovaries formed a distinct subgroup that may be more prone to develop various features of the insulin resistance syndrome."

Radon, PA et al. Impaired Glucose Tolerance in Pregnant Women with Polycystic Ovary Syndrome. Obstetrics and Gynecology. August 1999. 94(2):194-7.

22 women with PCOS were compared with 66 controls without PCOS, matched for age and weight. 41% of the women with PCOS got gd, whereas only 3% of controls did. Of the women with PCOS, 23% got pre-eclampsia vs. 1.5% of controls. "Women with PCOS are at increased risk of glucose intolerance and preeclampsia during pregnancy."

Urman, B et al. Pregnancy in Infertile PCOD Patients: Complications and Outcome. Journal of Reproductive Medicine. 1997. 42:501-505.

47 singleton pregnancies of women with PCOD were compared with those of 100 healthy controls. Significantly more PCOD women than controls had gd (13% vs. 2%). Pregnancy-induced hypertension was also more common in PCO moms (25% vs. 8%), as was severe pre-eclampsia (11% vs. 2%). However, the incidence of complications was not greater among obese PCOD patients compared to lean PCOD patients. Notes that another study found that glucose intolerance was particularly increased among the subset of women who were resistant to clomiphene citrate when attempting conception.

Lanzone, A et al. Polycystic Ovary Disease. A Risk Factor for Gestational Diabetes? Journal of Reproductive Medicine. April 1995. 40(4):312-6.

Examined the effect of higher pre-pregnancy levels of insulin on glycemic control in 12 women with PCOD once they became pregnant. Compared these women to 12 control women and 10 gd patients. 17% of the hyperinsulinemic PCOD patients got gd, and 25% got Impaired Glucose Tolerance in pregnancy. "In spite of their large increase in insulin secretion observed during pregnancy, patients with PCOD may develop a derangement of glycemic control, probably related to their pregestational insulinemic status."

Lesser, KB and Garcia, FA. Association Between Polycystic Ovary Syndrome and Glucose Intolerance During Pregnancy. Journal of Maternal Fetal Medicine. September 1997. 6(5):303-307.

Compared restrospectively the rates of gd among 24 PCO subjects and 44 general infertility control group subjects. More PCO women had a positive gd screening test, but the rate of gd was no higher than in other women with infertility.

Paradisi, G et al. Endocrino-Metabolic Features in Women with Polycystic Ovary Syndrome During Pregnancy. Human Reproduction. March 1998. 13(3):542-546.

Found a rate of 38% gd in women with PCO. Followed the concentrations of insulin and glucose over the course of pregnancy in PCO women, and found that early alteration of insulin sensitivity and secretion was particularly associated with the development of glucose tolerance abnormalities.


Breastfeeding in Pregnancy and Tandem Nursing

Moscone, S.R. and Moore, M.J. Breastfeeding During Pregnancy. Journal of Human Lactation. 1993. 9(2):83-88.

Studied the experiences of a group of mothers who conceived while breastfeeding and were highly motivated to continue breastfeeding. "Breastfeeding following conception did not appear to adversely affect the course of pregnancy among this group of women...a search of the medical literature of the past four years shows no published data specifically contraindicating continued nursing after conception." Their babies were born healthy and of appropriate birth weight.

Lawrence, Ruth A., M.D. Breastfeeding: A Guide for the Medical Profession. Third Edition. St. Louis: C.V. Mosby Company, 1989.

One of the classic breastfeeding texts used by professional lactation consultants and doctors. "There is no need to hastily wean the first infant from the is possible to lactate througout pregnancy and then to have two infants at the breast has been done by mothers who wish to maintain both infants at the breast that it can be done without any apparent effect on the nourishment of the new infant. Counseling of such a mother should take into account the mother's resources to get adequate rest, nourishment, and psychologic support to withstand the added demand on her, physically and mentally."

Mohrbacher, Nancy and Julie Stock. The Breastfeeding Answer Book. La Leche League International. 1997 Revised Edition. Available from

The ULTIMATE reference about breastfeeding and medical issues. Many local LLL chapters or leaders will have a copy of this book. Has a chapter on Breastfeeding During Pregnancy and Tandem Nursing (pp. 344-352). "A well-nourished mother should have no difficulty providing for both the unborn baby and the nursing child, if he is more than a year old. But it is important for her to gain weight at the appropriate rate and eat nutritious foods, as well as get sufficient rest. For some mothers, it may be necessary to consume extra calories while breastfeeding during pregnancy. Some mothers take extra vitamin supplements as a precaution...There is no documented danger to mother or fetus when mothers breastfeed through a healthy pregnancy. Although uterine contractions are experienced during breastfeeding, they are a normal part of pregnancy...uterine contractions also occur during sexual activity, which most couples continue during pregnancy. Even though some breastfeeding mothers notice stronger and more frequent contractions in later pregnancy, this does not seem to pose a danger to the unborn baby during a normal pregnancy...Medical reasons to consider weaning during pregnancy include uterine pain or bleeding, a history of premature delivery, or continued loss of weight by mother during pregnancy...During the last few months of pregnancy the milk changes to colostrum in preparation for the birth. The mother need not be concerned that the nursing child will 'use up' all the colostrum--no matter how much he nurses, colostrum will still be available at birth for the newborn."

Nichols-Johnson, Victoria, M.D. Tandem Nursing - Before and After. ABM NEWS and VIEWS: The Newsletter of The Academy of Breastfeeding Medicine. 1996. 2(1):6-7.

"One of the primary fears of nursing through a pregnancy stems from the fear that stimulation of the nipples by breastfeeding will cause the onset of premature labor. Although stimulation of the nipples causes the release of oxytocin, normal pregnancies do not seem to be adversely affected by this release during nursing. There may be some cramping while nursing, but this does not simulate contractions which produce dilation of the cervix. In contrast, weaning is advisable for women who have a history a multiple early pregnancy losses, preterm labor, or who are carrying muliple fetuses...Given a normal pregnancy, the decision to continue nursing an older sibling should be based on what is comfortable for the mother and child."

La Leche League Pamphlet. Nursing Two: Is It For You?. Available from

Discusses the issues of nursing through pregnancy and tandem-nursing siblings, and gives mothers encouragement and support for whatever decision they choose to make.

Nursing Mothers' Association of Australia. Breastfeeding Through Pregnancy and Beyond. 1993. May be available from professional lactation consultants and sometimes also from La Leche League leaders.

Discusses nutrition, miscarriage concerns, breast tenderness, nursing fears, handling disapproval, weaning if desired, tandem nursing two siblings after the new baby is born, etc. "In a normal, healthy pregnancy, with adequate rest and nutrition, there is usually no reason not to continue [nursing], and to [nurse] both babies after the newborn arrives."

Bumgarner, Norma Jane. Mothering Your Nursing Toddler. Newly revised edition. Available through

Classic book on continuing to nurse into toddlerhood and beyond, including a chapter on nursing in pregnancy and tandem-nursing. Great for women needing support in their decision to continue nursing beyond age one.



Copyright 1998-1999 KMom@Vireday.Com. All rights reserved. No portion of this work may be reproduced or sold, either by itself or as part of a larger work, without the express written permission of the author; this restriction covers all publication media, electrical, chemical, mechanical or other such as may arise over time.

[ Back to Kmom Area ]