Elective cesarean delivery is ineffective in protecting against in-utero meconium exposure of fetal myelomeningocele

Abstract

MECONIUM EXPOSURE OF FETAL MYELOMENINGOCELE CARL ROSE, JOSEPHINE WYATT-ASHMEAD, ANDREW PARENT, JAMES BOFILL, ALEXANDRA ASHMEAD, JOHN MORRISON, University of Mississippi Medical Center, Obstetrics & Gynecology, Jackson, Mississippi, University of Mississippi Medical Center, Pathology, Jackson, California, University of Mississippi Medical Center, Neurosurgery, Jackson, Mississippi, University of Mississippi Medical Center, Jackson, Mississippi OBJECTIVE: To determine if elective cesarean section following confirmation of fetal lung maturity but prior to onset of labor prevents in-utero meconium exposure of neural tissue in parturients with fetal myelomeningocele. STUDY DESIGN: In this retrospective case series 32 (17 male/15 female) with prenatally-diagnosed myelomeningocele underwent elective cesarean birth over a 4.5 year period. The mean EGA was 37.2 weeks and delivery followed confirmation of fetal lung maturity. All myelomeningoceles were repaired promptly (2.4 days) and the sacs were sent for pathologic examination. Amniotic membranes were also examined for evidence of microscopic meconium and intrauterine infection. Additionally, 23 placentas underwent histopathologic gross and microscopic examination. RESULTS: Gross meconium staining was noted in 3 cases. Meconium staining was detected microscopically in 32/32 (100%) of amniotic membrane samples and all (23/23) placental specimens demonstrated meconium histiocytosis while features of acute infection were noted in only 3/23 (13%). CONCLUSION: Fetuses with myelomeningoceles typically have intrinsically defective gastrointestinal function and are likely to pass meconium in-utero remote from term. Unfortunately, elective cesarean delivery prior to labor does not protect against exposure to potentially toxic meconium. Antenatal surgical repair could prove effective at reducing or mitigating destructive effects of meconium on open neural tissue. S170 SMFM Abstracts