222 - Association Between Maternal Hypertension and Infant Neurodevelopmental Outcomes in Extremely Preterm Infants.

Maternal hypertension is associated with prematurity and its neonatal complications. It is unclear whether preterm infants exposed to maternal hypertension experience poorer neurodevelopmental outcomes compared to infants born prematurely without exposure to maternal hypertension.

Objective:

We aimed to assess the association between maternal hypertension and infant neurodevelopmental impairment (NDI) at 24 months among preterm infants born < 29 weeks’ gestation.

Design/Methods:

This retrospective study used data from two high-level neonatal units in Montreal, Quebec, 2011-2017. Our cohort included infants born between 23⁺⁰ and 28⁺⁶ weeks’ gestation. Exposure was maternal hypertension with/without small for gestational age (SGA). Outcomes were the presence of any or significant NDI; each was a composite of the presence of cerebral palsy, developmental delay (Bayley Scales of Infant and Toddler Development, third edition), hearing and/or visual impairment (at 18 to 24 months). Multivariable logistic regression models were used to calculate crude and adjusted odds ratios (ORs) with 95% confidence intervals (CIs) assessing associations between maternal hypertension with/without SGA and any or significant NDI, adjusting for gestational age as a continuous variable, rupture of membranes >24 hours, singleton status, diabetes and SGA status.

Results:

Of 1019 preterm infants, we included 647 infants (median gestational age 26 weeks, IQR: 25-28), of which 96 (15%) were exposed to maternal hypertension and 71 (7%) were exposed to maternal hypertension with SGA (Table 1). Compared with infants born to normotensive mothers, infants exposed to maternal hypertension had a higher risk of any NDI (n=55/96 (57%) vs. n=252/551 (46%); adjusted OR: 2.29; 95%CI=1.36-3.87) and significant NDI (n=21/96 (22%) vs n=86/551 (16%); adjusted OR: 2.01, 95% CI=1.02-3.95) at their follow-up (Table 2 & 3). When evaluating the interaction between SGA status and exposure to hypertension, the interaction term was not significantly associated with the infant's adverse outcome (Table 3). However, when only evaluating SGA infants exposed to a hypertensive environment to non-SGA infants exposed to a normotensive environment (Table 3), maternal hypertension was strongly associated with any NDI (OR: 4.88; 95%CI=1.80-13.22) and significant NDI (OR: 6.91; 95%CI=2.50-19.12).


Conclusion(s):

In this cohort of infants born < 29 weeks, maternal hypertension was associated with a higher risk of NDI at their follow-up. These results suggest a pronounced impact of in-utero exposure to a maternal hypertensive environment on fetal brain development.