Maternal weight gain and pregnancy outcomes in twin gestations

1. In a large cohort of women with twin gestations, gestational weight gain very often falls outside of established recommendations, contributing to adverse outcomes like preterm birth.

Evidence Level Rating: 2 (Good)

Pre-pregnancy BMI and gestational weight gain (GWG) are important determinants of pregnancy outcomes, with adverse effects seen in both insufficient and excessive weight gain. With regards to twin gestations, there are limited data as to the optimal range of GWG; as such, the Institute of Medicine (IOM) provides only provisional guidelines concerning GWG. This retrospective cohort study spanning 17 years sought to both clarify the recommendations from the IOM and delineate optimal GWG in twin gestations. 1,274 women met study inclusion criteria, with 247 included in the low-risk cohort (i.e. those with no risk factors and normal outcomes) and 1,027 in the high-risk cohort. Of those included for analysis, 43 were underweight, 777 were of normal weight, 278 were overweight, and 176 were obese. The primary outcome was preterm birth. It was found that almost half of the women in this cohort gained weight above or below current IOM recommendations. Low GWG was found to be associated with an increased risk of preterm birth and birthweight < 10th percentile, especially among women in the normal weight and obese cohorts. However, there was a reduction in the incidence of hypertensive disorders among these women. For those experiencing high GWG, there was an increased risk of hypertensive disorders but a reduction in the risk of birthweight < 10th percentile. Finally, for the obese cohort, the estimation of optimal GWG at 37 weeks of 9.3 to 16.3 kg appears to be more predictive of adverse outcomes than the IOM recommendation of 11.3 to 19.1 kg. These findings highlight GWG as a modifiable risk factor for adverse outcomes in twin gestations. Further, prospective studies are needed to optimize current recommendations to further enhance future outcomes.

Click to read the study in AJOG

Image: PD

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