Gestational Age of Delivery in Pregnancies Complicated by Chronic Hypertension

Abstract

Objective To identify the gestational age of planned delivery in pregnancies complicated by chronic hypertension that minimizes the risk of perinatal death and severe adverse events. Methods This was a retrospective cohort study of all singletons complicated by hypertension. Detailed patient-level information was collected by chart review, including indication for delivery. Planned delivery at 36–36.6, 37–37.6, 38–38.6, and 39–39.6 weeks was compared to expectant management beyond each respective gestational age. Patients were excluded for fetal anomalies, inaccurate dating, and major medical problems other than hypertension, diabetes or renal disease. The primary outcome was a composite of stillbirth, neonatal death, assisted ventilation, cord pH<7.0, 5-minute Apgar ≤3, and neonatal seizures. Secondary outcomes were preeclampsia, severe preeclampsia, primary cesarean, and infant length of stay >5 days. Groups were compared using Student’s t-test and χ2 tests. Results Six hundred eighty three women with hypertension reached 36 weeks. Patients with planned delivery <39 weeks were more likely to have baseline renal disease. Prior to 37 weeks, planned delivery was associated with a statistically significant increase in the primary composite adverse neonatal outcome (10.0% versus 2.6%, p=0.04); after 38 weeks, expectant management was associated with a non-statistically significant increase in the primary composite outcome (0% versus 2.3%, p=0.40). Expectant management beyond 39 weeks was associated with a statistically significant increase in severe preeclampsia (0 versus 10.3%, p=0.001). Conclusion Expectant management beyond 39.0 weeks was associated with increasing incidence of severe preeclampsia; planned delivery prior to 37 weeks was associated with an increase in adverse neonatal outcomes. Further, well-powered studies are needed to delineate the optimal gestational age of delivery.

Hypertensive Disorders of Pregnancy

“… Supplemental Vitamin C and E are not recommended and may in fact be associated with worse pregnancy outcomes (73).  Indications for delivery are similar to those of pre-eclampsia (see below); if no such indication arises delivery at 39 weeks appears optimum (77) Notes:…”

“…Though it is unlikely to be done at primary health care level, health providers should work to ensure this is available in the tertiary hospital setting. 77  Women in LMICs are usually referred to tertiary hospitals to receive all tests.…”

Diabetes during Pregnancy: A Maternal Disease Complicating the Course of Pregnancy with Long-Term Deleterious Effects on the Offspring. A Clinical Review

“…To improve pregnancy outcomes and minimize perinatal death, Harper et al compared perinatal outcomes of planned deliveries at 37, 38, 39, and 40 weeks to expectant management. In 4905 diabetic pregnancies—of them, 1012 insulin-dependent—the risk of perinatal death at any gestational age examined was low (3/1000 births), including patients who were insulin-dependent whose risk was 6/1000 births or fewer [ 177 ]. The risk of a composite adverse neonatal outcome that included assisted ventilation >30 min, birth injury, seizures, or 5-min Apgar score ≤ 3 was <2%.…”

Out of Office Blood Pressure Measurement in Pregnancy and the Postpartum Period

“…The accurate determination of BP during pregnancy is essential, as both under- and over-treatment of HTN may result in harm to the mother and/or fetus [23, 24]. Inadequate treatment increases the risk of placental abruption and maternal stroke, while over-treatment with antihypertensive medication can potentially reduce placental perfusion pressure resulting in placental insufficiency, fetal growth restriction, and premature delivery [1, 25–28]. Currently, decisions surrounding antihypertensive therapy for most individuals with HTN, regardless of pregnancy status, are primarily based on office BP which is only a brief snapshot and a poor surrogate for a patient’s ‘true’ BP [29, 30].…”