Elevated gestational BP ups risk of low birthweight, impaired maternal health
Rapid blood pressure (BP) elevations during the second trimester of pregnancy may pose an increased risk of delivering a low birthweight (LBW) infant, as well as contribute to impaired maternal liver, kidney and coagulation functions, according to a study presented at the 2018 American Heart Association (AHA) Scientific Sessions in Chicago, Illinois, US.
The analysis involved 21,620 women from a birth cohort in Wuhan, China who delivered live singletons between 37 and 44 weeks of gestation. None of the women gave birth to babies with birth defects, had pre-eclampsia, and used tobacco and consumed alcohol during pregnancy. [AHA 2018, abstract MP68]
Women who delivered LBW infants (<2,500 g) had dramatic increases in systolic (S)BP or diastolic (D)BP in two instances: between 15 and 24 weeks of gestation and after 28 weeks of gestation. In logistic regression models, the risk of LBW increased by up to 240 percent in high gestational SBP (≥140 mm Hg; odds ratio [OR], 3.40; 95 percent CI, 1.66–6.98; p=0.0009) and DBP (≥90 mm Hg; OR, 1.98; 1.07–3.65; p<0.03) categories.
Interestingly, preclinical high SBP (120–139 mmHg) was also associated with a higher risk of LBW (OR, 1.40; 1.02–1.91; p=0.036).
Aside from LBW risk, unfavourable effects on maternal health were seen. At late pregnancy, elevated gestational SBP and DBP correlated with significant alterations in liver enzymes, blood urea nitrogen, creatinine, uric acid levels, and activated partial thromboplastin time and prothrombin time.
“Hypertensive disorders of pregnancy are the leading causes of maternal morbidity and major health issues for women and their infants,” said one of the investigators, Dr Jie Hu from the Brown University School of Public Health in Rhode Island, US.
Such disorders have been associated with increased risk of stillbirth, foetal growth restriction (FGR), adverse birth outcomes, young adulthood cardiovascular diseases and maternal postpregnancy hypertension.
According to Hu, the present data demonstrate that elevated maternal BP at second trimester contributes to FGR and that gestational prehypertension (SBP 120–139 mm Hg; DBP 80–89 mm Hg) influences FGR and maternal health.