Youngstrom M, et al. - In this retrospective cohort study, the researchers intended to compare the perinatal outcomes of normotensive women with those of women with a history of chronic hypertension with normal blood pressures before 20 weeks of gestation, stratifying the latter by whether they were receiving antihypertensive medication. They found that women with chronic hypertension were at an increased risk of adverse perinatal outcomes compared with women without a diagnosis of chronic hypertension despite normal baseline blood pressures without medications before 20 weeks of gestation.

Methods

• From 2000 to 2014, a retrospective cohort study of all singletons with a history of chronic hypertension was conducted.
• Blood pressure greater than 140/90 mm Hg before 20 weeks of gestation, fetal anomalies, major medical problems other than hypertension, and diabetes were the exclusions in this study.
• A randomly selected group without a diagnosis of chronic hypertension was chosen using the same exclusion criteria for the same time period.
• After that, outcomes were compared among women without chronic hypertension, women with chronic hypertension on no antihypertensive medication but with blood pressures less than 140/90 mm Hg before 20 weeks of gestation, and women with chronic hypertension on antihypertensive medication with blood pressures less than 140/90 mm Hg before 20 weeks of gestation.
• A perinatal composite of stillbirth, neonatal death, respiratory support at birth, arterial cord pH less than 7, 5-minute Apgar score 3 or less, and seizures were the primary outcome .
• Preterm birth before 37 and 34 weeks of gestation, small for gestational age, and preeclampsia were the secondary outcomes evaluated.

Results

• According to the findings obtained, of 830 women with chronic hypertension and blood pressures less than 140/90 mm Hg before 20 weeks of gestation, 212 (26%) were not taking antihypertensive medication and 618 (74%) were.
• However, these groups were compared with 476 women without chronic hypertension.
• Findings revealed that women with hypertension were more likely to be older and have baseline renal disease and diabetes compared with women in the no hypertension group.
• It was found that the perinatal composite was more common in both hypertensive groups: no antihypertensive medication (9.9%) and antihypertensive medication (14.6%) compared with women in the control group (2.9%) (adjusted odds ratio [OR] 2.9, 95% CI 1.21–6.85 no antihypertensive medications compared with no chronic hypertension; adjusted OR 5.0, 95% CI 2.38–10.54 antihypertensive medications vs no chronic hypertension).
• It was noted that the risk of early preterm birth, small for gestational age, and preeclampsia was not significantly increased in women with chronic hypertension and no antihypertensive medications compared with women without chronic hypertension.