461: Resource utilization in low-risk pregnant women after 39 weeks by body mass index

Abstract

To compare medical resource utilization in the antepartum and intrapartum periods in low-risk women according to their body mass index (BMI). Secondary analysis of data from a multi-center randomized control trial of induction of labor at 390/7 - 394/7 weeks compared with expectant management in low-risk nulliparous women. The primary outcome of this analysis is time spent in L&D from admission to delivery. Antepartum and intrapartum patients’ utilization of resources were defined a priori in the parent trial. BMI at randomization was categorized into 4 groups (≥40, 30-39, 25-29, < 25 kg/m2). Multivariable generalized linear modeling and logistic regression were performed and 99% confidence intervals were calculated. 6,058 women, with data available, were included in the analysis with 53% with BMI ≥30 kg/m2. There were no differences in gestational age at randomization or in primary trial group assignments between the BMI groups (Table 1). Every 5-unit increase in BMI was associated with an average 11% increase in time spent in L&D. Increasing BMI was not associated with an increase in antepartum resource utilization with the exception of blood tests and urinalysis. However, BMI was associated with higher odds of intrapartum resource utilization and longer total hospital length of stay (LOS) from admission to discharge (Table 2). For example, every 5-unit increase in BMI was associated with an increase in the odds by 26% in administration of antibiotics, 58% increase in placement of intrauterine pressure catheter, and an average 5% increase in total inpatient LOS from admission to discharge. There were no interactions between primary trial assignment groups (induction vs expectant management) and BMI for any of these associations. We provide contemporary data on the effect of BMI on resource utilizations in low-risk women. Higher BMI was associated with longer time from admission to delivery and total hospital LOS as well as more frequent utilization of intrapartum resources. The increasing prevalence of obesity in the US puts significant burden on L&D resources.View Large Image Figure ViewerDownload Hi-res image Download (PPT)