Impact of Chronic Hypertension and Antihypertensive Treatment on Adverse Perinatal Outcomes: Systematic Review and Meta‐Analysis

Abstract

Background Maternal chronic hypertension is associated with adverse pregnancy outcomes. Previous studies examined the association between either chronic hypertension or antihypertensive treatment and adverse pregnancy outcomes. We aimed to synthesize the evidence on the effect of chronic hypertension/antihypertensive treatment on adverse pregnancy outcomes. Methods and Results Medline/PubMed, EMBASE, and Web of Science were searched; we included observational studies and assessed the effect of race/ethnicity, where possible, following a registered protocol (CRD42019120088). Random‐effects meta‐analyses were used. A total of 81 studies were identified on chronic hypertension, and a total of 16 studies were identified on antihypertensive treatment. Chronic hypertension was associated with higher odds of preeclampsia (adjusted odd ratio [aOR], 5.43; 95% CI, 3.85–7.65); cesarean section (aOR, 1.87; 95% CI, 1.6–2.16); maternal mortality (aOR, 4.80; 95% CI, 3.04–7.58); preterm birth (aOR, 2.23; 95% CI, 1.96–2.53); stillbirth (aOR, 2.32; 95% CI, 2.22–2.42); and small for gestational age (SGA) (aOR, 1.96; 95% CI, 1.6–2.40). Subgroup analyses indicated that maternal race/ethnicity does not influence the observed associations. Women with chronic hypertension on antihypertensive treatment (versus untreated) had higher odds of SGA (aOR, 1.86; 95% CI, 1.38–2.50). Conclusions Chronic hypertension is associated with adverse pregnancy outcomes, and these associations appear to be independent of maternal race/ethnicity. In women with chronic hypertension, those on treatment had a higher risk of SGA, although the number of studies was limited. This could result from a direct effect of the treatment or because severe hypertension during pregnancy is a risk factor for SGA and women with severe hypertension are more likely to be treated. The effect of antihypertensive treatment on SGA needs to be further tested with large randomized controlled trials.

Chronic hypertension and risk of preterm delivery: National Longitudinal Study of Adolescents to Adult Health

“…Chronic hypertension, defined as systolic blood pressure (SBP) ≥140 mmHg or diastolic blood pressure (DBP) ≥90 mmHg diagnosed before pregnancy or <20 weeks, is associated with two to three times increased risk of preterm delivery. [4][5][6][7][8][9] Placental pathology studies suggest this may be due to altered placentation, leading to reduced functional capacity of the placenta and impaired delivery of nutrients and oxygen to the fetus. 10,11 Thus, clinical recommendations suggest pregnant people with chronic hypertension receive increased surveillance of foetal growth and, potentially, antihypertensive medication.…”

“…Pre‐pregnancy maternal blood pressure plays a role in the development and vascular modelling of the placenta and is related to risk of preterm delivery. Chronic hypertension, defined as systolic blood pressure (SBP) ≥140 mmHg or diastolic blood pressure (DBP) ≥90 mmHg diagnosed before pregnancy or <20 weeks, is associated with two to three times increased risk of preterm delivery 4‐9 . Placental pathology studies suggest this may be due to altered placentation, leading to reduced functional capacity of the placenta and impaired delivery of nutrients and oxygen to the fetus 10,11 …”

Mediterranean Diet and Lifestyle Habits during Pregnancy: Is There an Association with Small for Gestational Age Infants? An Italian Single Centre Experience

“…Indeed, it is well-known that SGA is associated with nulliparity as a direct consequence of physiological conditions, supposing that each following pregnancy the body becomes more efficient [23]. As for pregnancy-related diseases, the percentage of women not developed gestational diabetes or pregnancy-induced hypertension was significantly higher in the non-SGA women than their counterparts confirming the role of gestational diabetes and hypertension as risk factors for neonatal complications, such as SGA [32,33].…”

Role of Antihypertensive Treatment and Blood Pressure Control in the Occurrence of Adverse Pregnancy Outcomes: a Population-Based Study of Linked Electronic Health Records

“…20 However, the 2 meta-analyses highlighted the risk of small-forgestational-age infants in women treated with β-blockers compared with the untreated hypertensive group. 5,20 Research based on real-world evidence, using routinely collected data from electronic health records have been conducted to evaluate and compare the effectiveness and safety of medicine, 30 and a few prior observational studies used data from electronic health record to assess the patterns and effect of the use of antihypertensive treatment during pregnancy. 10,[31][32][33] Most of the previous cohort studies of women with CH compared pregnancy outcomes without separating treated and untreated hypertensive groups.…”