Indomethacin Dosing and Constriction of the Ductus Arteriosus During Open Fetal Surgery for Myelomeningocele Repair.

INTRODUCTION

The use of perioperative tocolytic agents in fetal surgery is imperative to prevent preterm labor. Indomethacin, a well-known tocolytic agent, can cause ductus arteriosus (DA) constriction. We sought to determine whether a relationship exists between preoperative indomethacin dosing and fetal DA constriction.

MATERIALS AND METHODS

This is an IRB-approved, single-center retrospective observational case series of 42 pregnant mothers who underwent open fetal myelomeningocele repair. Preoperatively, mothers received either 1 (QD) or 2 (BID) indomethacin doses. Maternal anesthetic drug exposures and fetal cardiac dysfunction measures were collected from surgical and anesthesia records and intraoperative fetal echocardiography. Pulsatility Index was used to calculate DA constriction severity. Comparative testing between groups was performed using t- and chi-square testing.

RESULTS

DA constriction was observed in all fetuses receiving BID indomethacin and in 71.4% of those receiving QD dosing (p = 0.0002). Severe DA constriction was observed only in the BID group (35.7%). QD indomethacin group received more intraoperative magnesium sulfate (p < 0.0001). Minimal fetal cardiac dysfunction (9.5%) and bradycardia (9.5%) were observed in all groups independent of indomethacin dosing.

CONCLUSIONS

DA constriction was the most frequent and severe in the BID indomethacin group. QD indomethacin and greater magnesium sulfate dosing was associated with reduced DA constriction.

© 2018 S. Karger AG, Basel.