989: Obstetric outcomes and placental findings in gestational diabetes patients according to pre-gestational weight and weight gain

Abstract

We aimed to assess clinical outcomes and placental lesions among gestational diabetes patients according to pre-gestational weight and weight gain during pregnancy. This was a cohort of all GDM deliveries at our institution during 2009-2015. We defined two groups: high BMI group - pre-gestational BMI >30 and or gestational weight gain>20 kg, and normal BMI group. Placentas were examined by a single pathologist and described according to new Redline classification. Placental weight (PW) was noted, as were additional histopathological findings. 685 deliveries with a diagnosis of GDM were reviewed (3.2% of all deliveries). BMI status was available for 429 patients, of which 221 (51.5%) had a high BMI and 208 (48.3%) had a normal BMI. Pathological reports were available for 144 of these patients. Similar age, gravidity and parity were noted in both groups, but high BMI patients displayed a higher rate of GDMA2 (41.6% vs. 30.2%, p=0.01). Despite similar gestational age at delivery, high BMI patients’ birth weight was significantly higher (3475 ± 508 gr vs. 3242 ± 503 gr, p<0.001) with more large for gestational age neonates (33.1% vs. 13.9%, p<0.001), and a trend for more cesarean deliveries (CD), 49.3% vs. 40.8%, p=0.07. By logistic regression, past CD and high BMI were independently associated with CD, while GDM type and birth weight were non-significant. Placental weight was increased among high BMI patients. However, this did not retain significance after adjustment for birth weight, and GDM type. No differences were demonstrated in other placental histological findings. GDM pregnancies accompanied by increased weight gain or elevated pre-gestational BMI are associated with adverse obstetric outcomes, despite similar placental findings. Patient should be advised regarding these outcomes, as gestational weight gain may determine delivery mode.