Blood pressure change across pregnancy in white European and south Asian women: Analysis using data from the born in Bradford cohort

Publication authors

Farrar D.; Santorelli G.; Lawlor D.; Macdonald-Wallis C.; Tuffnell D.; Sheldon T.


Introduction Hypertensive disorders of pregnancy (HDP) affect increasing numbers of women and are associated with maternal and infant morbidity and mortality. Early recognition and treatment improve outcomes; however, it is unclear if patterns of blood pressure (BP) change and prevalence of HDP are influenced by ethnicity.

Aim: To determine whether patterns of BP change differ between white European (WE) and south Asian (SA) women and the prevalence of HDP, using current National Institute for Health and Care Excellence (NICE) recommended criteria.

Methods Linear spline models, with five parameters (8, 8-24, 24-30, 30-36, >36 weeks of gestation) and prevalence estimates of HDP were produced using data from the Born in
Bradford study. Results Of 10 535 eligible women, 4444 were WE and 5427 were SA. Unadjusted analysis suggests that SA women have significantly lower systolic (SBP) and diastolic (DBP) BP than WE women from early pregnancy and that this difference continues to term. Mean difference in SBP between the two groups at <8 weeks and at >36 weeks was -4.80 mmHg (95% CI -4.81 to -4.79) and -5.27 mmHg (95% CI -5.31 to -5.23), respectively. In all, 1050 (24%; 95% CI 22.4-24.8) WE and 690 (13%; 95% CI 11.5-13.6) SA women developed hypertension and 487 (13%; 95% CI 11.5-13.6) WE and 350 (7%; 95% CI 6.2-7.6) SA women developed preeclampsia.

Conclusion SA women have significantly lower DBP and SBP early in pregnancy than WE women; this pattern continues to term. Using current (NICE) threshold criteria, SA women are less likely to develop HDP. Further research is needed to examine variations in the risk of adverse outcomes for graded increases in BP.