Oral Concurrent Session 2 - Clinical Obstetrics and Quality
Oral Concurrent Sessions
Bonnie L. Hermann, MD
Maternal-Fetal Medicine Fellow
UTHealth Houston
Houston, Texas, United States
Cassidy A. O'Sullivan, MD
OB/GYN Resident
Christiana Care Health System
Newark, Delaware, United States
Fabrizio Zullo, MD (he/him/his)
Ob/Gyn Resident
University of Rome La Sapienza
Rome, Lazio, Italy
Suneet Chauhan, DSc, MD
Christiana Care
Newark, Delaware, United States
Hector M. Mendez-Figueroa, MD
Associate Professor
McGovern Medical School at UTHealth
Houston, Texas, United States
The primary objective was to compare the rate of cesarean delivery (CD) among individuals with newborns with aberrant growth (i.e. small- or large-for gestational age; SGA or LGA) who were induced versus expectantly managed in the ARRIVE trial. The secondary objectives were to compare the rate of hypertensive disorders of pregnancy (HDP), composite neonatal and maternal adverse outcome (CNAO, CMAO) . We hypothesized that the rate of CD would be lower among those with newborns with aberrant growth who were induced versus those expectantly managed.
Study Design:
A secondary analysis of the ARRIVE trial was performed, with the inclusion criteria of known gestational age and birthweight (BW). Newborns were classified as SGA (BW < 10%) or LGA (BW > 90%), using the nomogram by Alexander et al. CNAO and CMAO are defined in the Table. Relative risks (RR), 95% confidence intervals (CI) and number needed to treat (NNT) were calculated.
Results:
The rate of aberrant growth was 14.0% (430/3,059) in the induced group and 13.9% (423/3,037) in the expectantly managed group (p= 0.17). CD rate among those with SGA or LGA newborns was significantly lower for those induced (21.6%) vs those expectantly managed (28.6%; RR 0.75, 95% CI 0.58-0.99). HDP also differed significantly between the two groups (9.7% vs 16.8%; RR 0.58; 95% CI 0.40-0.85).The NNT for induction to decrease the rate of CD and HDP among SGA or LGA was 14. The rate of CNAO was similar among the two groups: 7.2% in the induced vs. 7.7% in the expectantly managed group. Likewise, the CMAO—22.6% in the induced group versus 22.3% in the expectantly managed group—did not differ between the groups (p=0.91; Table).
Conclusion:
Among low-risk pregnancies with either SGA or LGA, induction at 39 weeks, compared to expectant management, was associated with 25% reduction in the rate of cesarean delivery and 42% reduction in hypertensive disorder, albeit with no difference in composite neonatal or maternal adverse outcomes. This finding provides support for induction of labor at 39 weeks especially for individuals with suspected neonatal aberrant growth.
