580 Maternal factors influence delivery route more than fetal factors in prenatally diagnosed congenital heart disease

Abstract

For poorly understood reasons, women with prenatally diagnosed congenital heart disease (CHD) have demonstrated increased cesarean delivery (CD) rates, with no discernable improvement in outcomes. We aim to examine indications for delivery, indications for CD and risk factors associated with CD. Retrospective cohort of 322 singleton pregnancies prenatally diagnosed with moderate to severe CHD requiring surgical intervention in first year of life. Patients with Trisomy 13 or 18 were excluded. We compared contributing maternal and fetal factors for correlation with delivery route. Statistical analysis was completed by Chi-square and Fisher exact tests to compare categorical variables and two-tailed unpaired T-test for continuous variables. Logistic regression risk ratios were utilized to estimate effect size. In the cohort, 147 women underwent CD (rate 46%, 95%CI 40, 51%). Of all CD, 31.3% (95%CI 23.8, 38.7) were secondary to urgent fetal indications. Maternal indications accounted for 42.2% of CD (95%CI 34.2, 50.2%). If CD occurred during labor, 66.7% (95%CI 51.3, 82.1) were due to abnormal fetal heart rate tracing. However, 79.7% of inductions resulted in vaginal delivery (VD) (95%CI 72.8, 86.8) and spontaneous labor resulted in VD in 84.7% (95%CI 75.3, 94.2). Factors significantly associated with CD include morbid obesity (RR 3.0, 95%CI 1.5, 6.1), diabetes (RR 3.9, 95%CI 2.0, 7.3) and severe pre-eclampsia (6.0, 95%CI 1.7, 21.4). Late preterm and early term deliveries were associated with a higher CD rate (2.3, 95%CI 1.2, 4.3 and 1.7, 95%CI 1.1, 2.7, respectively). Fetal growth restriction was associated with CD (RR 3.8, 95%CI 1.6, 9.2). Of the 10 most frequent CHD diagnoses encountered, only hypoplastic left heart was associated with CD (OR 1.9, 95%CI 1.02, 3.4). Although the CD rate is higher in women with fetal CHD, most indications for CD are maternal. Induction and spontaneous labor are successful in this patient population.View Large Image Figure ViewerDownload Hi-res image Download (PPT)