Maternal blood pressure, cord glucocorticoids, and child neurodevelopment at 2 years of age: A birth cohort study

Abstract

BACKGROUND Pregnancy hypertensive disorders have impaired neurodevelopment in offspring. We aimed to explore the association of normal range maternal blood pressure (BP) with child neurodevelopment, as well as the possible role of placental 11-beta-hydroxysteroid dehydrogenase type 2 (11β-HSD2) therein. METHODS Among 1,008 mother–child pairs recruited in Wuhan, China, in 2013–2015, we measured maternal third-trimester BP (systolic BP (SBP) and diastolic BP (DBP)) and cord glucocorticoids (cortisol and cortisone), a marker reflecting placental 11β-HSD2 activity. We evaluated child neurodevelopment using the Bayley Scales of Infant Development (BSID) with obtaining the Mental and Psychomotor Development Index (MDI and PDI). Multiple regression and mediation analysis were performed to estimate the effect. RESULTS Each 5 mm Hg increase in maternal third-trimester SBP was associated with 1.54 points decrease in MDI (95% confidence interval (CI) = –2.60 –0.48) and 1.23 points decrease in PDI (95% CI = –2.14, –0.31); similar association was observed between DBP and BSID (adjusted β = –1.32; 95% CI = –2.53, –0.10 for MDI and –1.37; 95% CI = –2.42, –0.33 for PDI). Also, we found significant associations between cord cortisol/cortisone ratio and PDI (adjusted β = 2.95; 95% CI = 0.91, 4.99), as well as between maternal BP and cord cortisol/cortisone ratio (adjusted β = –0.03; 95% CI = –0.06, –0.01 for both SBP and DBP). Mediation analysis revealed that cord cortisol/cortisone ratio explained 6.29% of the association between SBP and PDI, and 6.85% between DBP and PDI. CONCLUSIONS Increased maternal normal range BP may affect child neurodevelopment. Furthermore, placental 11β-HSD2 activity might be involved in the process.