Increasing SBP in pregnancy tied to worse maternal, foetal outcomes

A moderately increasing trend in systolic blood pressure (SBP) in pregnant mothers increases the risk of adverse maternal and foetal outcomes, a recent study has found.

The study included 63,724 pregnant women who had had their blood pressures measured throughout pregnancies. The main outcomes were maternal variables, such as placental abruption, premature rupture of membranes and perinatal haematoma, and foetal outcomes, including low birth weight, preterm birth and low Apgar scores at 1–5 minutes.

Four different SBP trajectories emerged: low-stable (104.08–119.81 mm Hg; n=31,853), moderate-stable (116.71–129.17 mm Hg; n=30,507), high-decreasing (120.52–156.93 mm Hg; n=229) and moderate-increasing (118.89–144.38 mm Hg; n=1,135).

Babies born to mothers in the high-decreasing or moderate-increasing SBP trajectory groups tended to have lower birth weights than their low-stable or moderate-stable counterparts. Apgar score at 1 or 5 minutes was also lower in foetuses in the moderate-increasing group.

Logistic regression models confirmed these associations. Relative to low-stable babies, those born to mothers with moderate-increasing SBP were significantly more likely to have low birth weight (adjusted odds ratio [OR], 6.30, 95 percent confidence interval [CI], 5.00–7.94), preterm birth (adjusted OR, 2.99, 95 percent CI, 2.40–3.71), and low Apgar scores at 1 or 5 minutes (adjusted OR, 2.05, 95 percent CI, 1.25–3.35).

SBP patterns also affected maternal outcomes. Women with moderate-increasing SBP were at greater risk of placental abruption (adjusted OR, 4.17, 95 percent CI, 2.22–7.84), premature rupture (adjusted OR, 1.51, 95 percent CI, 1.22–1.87) and prenatal haematoma (adjusted OR, 7.36, 95 percent CI, 2.73–19.83).