Neonatal outcomes of pregnancy in women with congenital heart disease

Background

Infants born to women with congenital heart disease (CHD) are at increased risk for adverse outcomes compared with the general population. There are few large, contemporary studies examining the relationship between CHD severity, maternal risk factors and neonatal outcomes.

Methods

Data on women with CHD who had a live birth from 2011 through 2014 in geographic areas in Georgia, North Carolina and Utah were analyzed. Maternal CHD was identified from clinical and administrative data collected for the CDC Lifespan CHD surveillance project. CHD was categorized as severe and non-severe (shunt, valve or shunt+valve lesions). Linked birth certificates provided information on neonatal outcomes and neonatal, maternal and pregnancy characteristics. Neonatal outcomes included preterm delivery (<37 weeks), low birth weight (<2,500 grams), small for gestational age (SGA), neonatal intensive care unit (NICU) admission, a composite of any adverse outcome (one or more of preterm delivery, SGA or NICU admission), and CHD. Neonatal outcomes were summarized using descriptive statistics. Differences by maternal CHD severity were assessed using Wilcoxon rank-sum and Chi-square tests for continuous and categorical variables, respectively. The association of maternal and pregnancy characteristics (race, pregestational diabetes (PGDM), hypertensive disorders of pregnancy (HDP), prior preterm birth, non-singleton pregnancy, maternal age, previous living live birth and CHD severity) with neonatal outcomes were assessed using logistic regression fit using generalized estimating equations clustered on mother and adjusted for mother’s age, birth year and geographical location of delivery.

Results

Of the 2,411 liveborn infants born to 1,982 women with CHD (34% with severe CHD), 19% were preterm, 18% were of low birth weight, 14% were SGA and 4.2% were diagnosed with CHD. Of the included infants, 25% required NICU and 40% experienced the composite adverse outcome. Infants born to mothers with severe CHD (vs non-severe) were more likely to experience the composite adverse outcome (aOR 2.1 [1.8, 2.5]) and CHD recurrence (aOR 17.1 [9.3, 31.5]). In a multivariable analysis, severe CHD (vs non-severe, aOR 2.2 [1.8, 2.7]), Black race (vs White, aOR 1.8 [1.4, 2.3]), PGDM (aOR 2.5 [1.3, 5.0]), hypertensive disorder of pregnancy (aOR 2.1 [1.5, 3.1]), prior preterm birth (aOR 2.0 [1.3, 3.1]), and non-singleton pregnancy (aOR 6.7 [3.8, 11.6]) were associated with increased risk of the composite adverse outcome.

Conclusions

Nearly half of infants born to women with CHD experienced the adverse composite neonatal outcome, with the highest risk among those born to women with severe CHD. In addition to CHD severity, risk factors for adverse neonatal outcomes among women with CHD included black race, hypertensive disorders of pregnancy, PGDM, prior preterm birth and non-singleton pregnancy. These findings can help provide individualized counseling about neonatal risks for women with CHD.