Maternal hypertensive disorders in pregnancy and risk of hypoxic-ischemia encephalopathy

Abstract

Background

Hypoxic–ischemic encephalopathy (HIE) is one of the most serious birth complications for neonates. Few studies reported the relationship between maternal blood pressure disorders and risk of neonatal HIE.

Objective

This study was conducted to examine whether maternal hypertensive disorders in pregnancy increase the risk of HIE.

Methods

The analyses were performed using data from a large population-based cohort study aiming to prevent neural tube defects by supplementation with folic acid. The subjects comprised 183,981 women with singleton live births delivered at gestational ages of 32–42 weeks, who registered in two southern provinces in China. Blood pressure was measured by trained health care workers at each prenatal visit. Diagnosis information on HIE was recorded at the time of delivery.

Results

Totally 19,298 women (10.49%) were diagnosed with maternal hypertensive disorders in pregnancy and 255 infants (1.4 per 1000) with HIE, respectively. Compared with the normotensive group, a great increment in the risk of HIE was observed in women with hypertensive disorders (adjusted RR = 2.40, 95% confidence interval [CI]: 1.79–3.22) after adjusting for maternal confounding factors. A greater association was presented among preterm (32–36 weeks) infants with an adjusted RR of 5.45 (95% CI: 2.79, 10.65) compared to a RR of 2.09 (95% CI: 1.49, 2.92) among full-term (37–42 weeks) infants (p for heterogeneity < .05). Further stratification analyses showed that no matter with or without small for gestational age (SGA), maternal hypertensive disorders were associated with the increased risk for HIE. Sensitivity analyses excluding infants with low or high birth weight did not appreciably change the findings.

Conclusions

Our present study demonstrated a positive association of maternal hypertensive disorders in pregnancy with the risk of neonatal HIE.

Keywords:

• Blood pressure
• cohort study
• hypertensive disorders
• Hypoxic–ischemic encephalopathy

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was funded by the cooperative agreement between the US Centers for Disease Control and Prevention and Peking University Health Science Center [U01 DD000293]. The funding sources were not involved in the study design, data analysis and interpretation, writing of the manuscript, or the decision to submit for publication.