Skip to main content
PMC home page
NIHPA Author Manuscripts logoLink to NIHPA Author Manuscripts
. Author manuscript; available in PMC: 2018 Dec 14.
Published in final edited form as: N Engl J Med. 2016 Jun 23;374(25):2501. doi: 10.1056/NEJMc1603067

Metformin versus Placebo in Obese Pregnant Women without Diabetes

Fatima C Stanford 1, Nasreen Alfaris 1, Madhusmita Misra 1
PMCID: PMC6294119  NIHMSID: NIHMS995339  PMID: 27332918

To the Editor:

Syngelaki et al. (Feb. 4 issue)1 describe the efficacy of metformin in reducing gestational weight gain in women with a bodymass index (BMI; the weight in kilograms divided by the square of the height in meters) of more than 35. Although their study does not show a reduction in the neonatal birth weight, their results underscore the ability of metformin to reduce gestational weight gain in women with moderate-to-severe obesity without diabetes.

One question is whether the exclusion of patients who were started on insulin after the oral glucose-tolerance test would alter the results of the study. Another question is whether a larger sample size would result in significant results for the proportion of women with miscarriages, premature births, or live births across groups. Studies have shown that metformin is safe during pregnancy, with efficacy in treating gestational diabetes mellitus and the polycystic ovary syndrome, and that the drug has no effect on the growth of several cancers.2,3 It would be interesting if the authors of this and concurrent studies were to consider whether the use of metformin during pregnancy in women who are obese (BMI, >30) and those who are not obese (BMI, ≤30) would decrease weight retention after birth.1,4 Postpartum weight retention contributes to obesity in all weight classes, and the use of metformin would be an attractive option to reduce this risk.5

Footnotes

No potential conflict of interest relevant to this letter was reported.

References

  • 1.Syngelaki A, Nicolaides KH, Balani J, et al. Metformin versus placebo in obese pregnant women without diabetes mellitus. N Engl J Med 2016; 374: 434–43. [DOI] [PubMed] [Google Scholar]
  • 2.Glueck CJ, Wang P, Kobayashi S, Phillips H, Sieve-Smith L. Metformin therapy throughout pregnancy reduces the development of gestational diabetes in women with polycystic ovary syndrome. Fertil Steril 2002; 77: 520–5. [DOI] [PubMed] [Google Scholar]
  • 3.Sivalingam VN, Myers J, Nicholas S, Balen AH, Crosbie EJ. Metformin in reproductive health, pregnancy and gynaecologi-cal cancer: established and emerging indications. Hum Reprod Update 2014; 20: 853–68. [DOI] [PubMed] [Google Scholar]
  • 4.Chiswick C, Reynolds RM, Denison F, et al. Effect of metformin on maternal and fetal outcomes in obese pregnant women (EMPOWaR): a randomised, double-blind, placebo-controlled trial. Lancet Diabetes Endocrinol 2015; 3: 778–86. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 5.Endres LK, Straub H, McKinney C, et al. Postpartum weight retention risk factors and relationship to obesity at 1 year. Obstet Gynecol 2015; 125: 144–52. [DOI] [PMC free article] [PubMed] [Google Scholar]

RESOURCES