Neonatal respiratory outcomes in pregnancy induced hypertension: introducing a novel index

Abstract

Objective: To evaluate short-term respiratory outcomes, mortality and bronchopulmonary dysplasia (BPD) in preterm infants born to mothers with and without pregnancy induced hypertension (PIH).

Methods: Exposed infants <33 weeks’ gestation were matched to controls in a 1:2 ratio, based on gestation, sex and antenatal steroid exposure in this retrospective cohort study. Primary outcomes were a novel cumulative respiratory index (cRI) (product of mean airway pressure-hours and FiO₂-hours while on invasive ventilation during first 72 hours), mortality and BPD.

Results: Seventy-nine exposed infants were matched with 158 controls. cRI was higher in exposed infants (median 1854; IQR 186–13,901) versus controls (median 1359; IQR 210–11,302) but not statistically significant (p = .63). On conditional regression analysis, PIH did not predict cRI (adjusted β = 0.96; 95% CI = 0.79–1.17; p = .712). No association between PIH and mortality (unadjusted odds ratio [OR] = 3.14; 95% CI = 0.76–13.0; p=.11) was identified. PIH was significantly associated with BPD on univariate analysis (OR = 2.29; 95% CI = 1.02–5.17; p=.046), but not after adjustment (aOR = 1.26; 95% CI = 0.38–4.19; p=.7).

Conclusions: PIH was not associated with cRI, mortality or BPD in this study. Further validation of cRI and exploration of its relationship with PIH as well as neonatal outcomes is warranted.

Keywords:

• Gestational hypertension
• hypertensive disorder of pregnancy
• matched cohort
• preeclampsia
• cumulative respiratory index

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was funded by McMaster University Pediatrics Subspecialty Resident Research Award [ID 2000007347].