BODY MASS INDEX GAIN DURING PREGNANCY ADVERSELY AFFECTS LABOR PROCESS
Department of Obstetrics & Gynecology, Faculty of Medicine, Benha University
Objectives: To evaluate the effect of excessive body mass index gain (BMIG) on labor progress and its maternal outcome. Patients & Methods: The study included 554 pregnant women fulfilling the inclusion criteria. At time of booking, body height and weight were determined and body mass index (BMI) was calculated. At expected date for delivery, BMI was determined and the percentage of excess BMI gain (%EBMIG) was calculated. Maternal outcomes included the frequency of postdated (PD) labor, defined as pregnancy prolonged beyond 294 days, frequency of women required induction of labor, labor augmentation, instrumental labor and/or cesarean section (CS). The relation between %EBMIG and maternal outcomes was determined and the probable cutoff points of %EBMIG for prediction of labor-associated outcomes were determined. Results: Distribution of enrolled women among BMI grades significantly changed at expected time of delivery with significantly higher BMI compared to booking time. At expected time of delivery, all women got higher BMI with a mean %EBMIG of 19.8±7.1; range: 8-38%. Majority of women (n=286; 51.6%) got increased BMI in range of 10-20%, while 183 women (33%) had increased BMI in range of 20-30% and 64 women had %EBMIG of more than 30%. Forty-nine women had PD labor for a frequency of 8.8%. Two hundred and sixty-one (47.1%) women received induction of labor that resulted in spontaneous unaided vaginal delivery in 83 women, 96 women had instrumental delivery, while 82 had CS. There was positive significant correlation between %EBMIG during pregnancy and development of PD, requirement for labor induction, and augmentation and rate of CS. Kaplan-Meier analysis defined %EBMIG during pregnancy of 32.7, 25.2, 27.6 and 31.6% as the cutoff points for prediction of PD, need for induction of labor, need for labor augmentation and CS. Conclusion: Pregnant women with excessive weight grain during pregnancy are at a risk of postdated delivery by a frequency of 8.8% and requiring induction and augmentation of labor with high frequency. Failure to achieve vaginal delivery and need for CS is a frequent event. Labor-related complications are positively related to the extent of BMI gain during pregnancy. The %EBMIG of ≥25% could be a cutoff level for prediction of high frequency of labor-related complications.