Treatment for Mild Chronic Hypertension during Pregnancy.

BACKGROUND: The benefits and safety of the treatment of mild chronic hypertension (blood pressure, <160/100 mm Hg) during pregnancy are uncertain. Data are needed on whether a strategy of targeting a blood pressure of less than 140/90 mm Hg reduces the incidence of adverse pregnancy outcomes without compromising fetal growth. METHODS: In this open-label, multicenter, randomized trial, we assigned pregnant women with mild chronic hypertension and singleton fetuses at a gestational age of less than 23 weeks to receive antihypertensive medications recommended for use in pregnancy (active-treatment group) or to receive no such treatment unless severe hypertension (systolic pressure, ≥160 mm Hg; or diastolic pressure, ≥105 mm Hg) developed (control group). The primary outcome was a composite of preeclampsia with severe features, medically indicated preterm birth at less than 35 weeks' gestation, placental abruption, or fetal or neonatal death. The safety outcome was small-for-gestational-age birth weight below the 10th percentile for gestational age. Secondary outcomes included composites of serious neonatal or maternal complications, preeclampsia, and preterm birth. RESULTS: A total of 2408 women were enrolled in the trial. The incidence of a primary-outcome event was lower in the active-treatment group than in the control group (30.2% vs. 37.0%), for an adjusted risk ratio of 0.82 (95% confidence interval [CI], 0.74 to 0.92; P<0.001). The percentage of small-for-gestational-age birth weights below the 10th percentile was 11.2% in the active-treatment group and 10.4% in the control group (adjusted risk ratio, 1.04; 95% CI, 0.82 to 1.31; P = 0.76). The incidence of serious maternal complications was 2.1% and 2.8%, respectively (risk ratio, 0.75; 95% CI, 0.45 to 1.26), and the incidence of severe neonatal complications was 2.0% and 2.6% (risk ratio, 0.77; 95% CI, 0.45 to 1.30). The incidence of any preeclampsia in the two groups was 24.4% and 31.1%, respectively (risk ratio, 0.79; 95% CI, 0.69 to 0.89), and the incidence of preterm birth was 27.5% and 31.4% (risk ratio, 0.87; 95% CI, 0.77 to 0.99). CONCLUSIONS: In pregnant women with mild chronic hypertension, a strategy of targeting a blood pressure of less than 140/90 mm Hg was associated with better pregnancy outcomes than a strategy of reserving treatment only for severe hypertension, with no increase in the risk of small-for-gestational-age birth weight. (Funded by the National Heart, Lung, and Blood Institute; CHAP ClinicalTrials.gov number, NCT02299414.).

Blood Pressure Control in Pregnant Patients with Chronic Hypertension and Diabetes: Should <130/80 be the Target?

BACKGROUND: The Chronic Hypertension and Pregnancy Study (CHAP) demonstrated that a target blood pressure of <140/90 mm Hg during pregnancy is associated with improved perinatal outcomes. Outside of pregnancy, pharmacologic therapy for patients with diabetes and hypertension is adjusted to a target blood pressure of <130/80 mm Hg. During pregnancy, patients with both diabetes and chronic hypertension may also benefit from tighter control with a target blood pressure (BP) <130/80 mm Hg. OBJECTIVE: We compared perinatal outcomes in patients with hypertension and diabetes who achieved BP <130/80 versus 130-139/80-89 mm Hg. STUDY DESIGN: This was a secondary analysis of a multi-center randomized controlled trial. Participants were included in this secondary analysis if they had diabetes diagnosed prior to pregnancy or at <20 weeks' gestation and at least two recorded BP measurements prior to delivery. Average systolic and diastolic BP were calculated using ambulatory antenatal BPs. The primary composite outcome was preeclampsia with severe features, indicated preterm birth <35 weeks, or placental abruption. Secondary outcomes were components of the primary outcome, cesarean delivery, fetal or neonatal death, neonatal intensive care unit (NICU) admission, and small for gestational age (SGA). Comparisons were made between those with an average systolic BP <130 mm Hg and average diastolic BP <80 mm Hg and those with an average systolic blood pressure 130-139 mm Hg or diastolic blood pressure 80-89 mm Hg using Student's t-test and chi-squared tests. Multivariable log-binomial regression models were used to evaluate risk ratios between blood pressure groups for dichotomous outcomes while accounting for baseline covariates. RESULTS: Of 434 participants included, 150 (34.6%) had an average blood pressure less than 130/80 mm Hg. Participants with an average blood pressure less than 130/80 were more likely to be on antihypertensive medications at the start of pregnancy and more likely to have newly diagnosed DM prior to 20 weeks. Participants with an average blood pressure less than 130/80 mm Hg were less likely to have the primary adverse perinatal outcome (19.3% vs 46.5%, adjusted relative risk (aRR) 0.43, 95% CI 0.30-0.61, p<0.01), with decreased risks specifically of preeclampsia with severe features (aRR 0.35, 95% CI 0.23-0.54) and indicated preterm birth prior to 35 weeks (aRR 0.44, 95% CI 0.24-0.79). The risk of NICU admission was lower in the lower blood pressure group (aRR 0.74, 95% CI 0.59-0.94). No differences were noted in cesarean delivery (aRR 1.04, 95% CI 0.90-1.20), fetal or neonatal death (aRR 0.59, 95% CI 0.12-2.92). SGA less than the 10th percentile was lower in the lower blood pressure group (aRR 0.37, 95% CI 0.14-0.96). CONCLUSION: In those with chronic hypertension and diabetes prior to 20 weeks, achieving an average goal blood pressure of <130/80 mm Hg may be associated with improved perinatal outcomes.

Long-term neurodevelopmental follow-up of children exposed to pravastatin in utero.

BACKGROUND: Preeclampsia, especially before term, increases the risk of child neurodevelopmental adverse outcomes. Biological plausibility, preclinical studies, and pilot clinical trials conducted by the Eunice Kennedy Shriver National Institute of Child Health and Human Development and the Obstetric-Fetal Pharmacology Research Centers Network support the safety and use of pravastatin to prevent preeclampsia. OBJECTIVE: This study aimed to determine the effect of antenatal pravastatin treatment in high-risk pregnant individuals on their child's health, growth, and neurodevelopment. STUDY DESIGN: This was an ancillary follow-up cohort study of children born to mothers who participated in the Obstetric-Fetal Pharmacology Research Centers Network pilot trials of pravastatin vs placebo in individuals at high risk of preeclampsia (ClinicalTrials.gov; identifier NCT01717586). After obtaining written informed consent (and assent as appropriate), the parent was instructed to complete the Child Behavior Checklist. To assess the child's motor, cognitive, and developmental outcomes, a certified and blinded study psychologist completed child motor, cognitive, emotional, and behavioral assessments using validated tools. Given the small number of individuals in the studies, the 10- and 20-mg pravastatin groups were combined into 1 group, and the results of the pravastatin group were compared with that of the placebo group. RESULTS: Of 40 children born to mothers in the original trial, 30 (15 exposed in utero to pravastatin and 15 to placebo) were enrolled in this follow-up study. The time of follow-up, which was 4.7 years (interquartile range, 2.5-6.9), was not different between children in the pravastatin group and children in the placebo group. There was no difference in the child's body mass index percentiles per sex and corrected age, the rates of extremes of body mass index percentiles, or the report of any other medical or developmental complications between the 2 groups. No child born in the pravastatin group had any limitation in motor assessment compared with 2 children (13.3%) who walked with difficulty and 4 children (26.7%) who had reduced manual abilities in the placebo group. Moreover, children born to mothers who received pravastatin had a higher general mean conceptual ability score (98.2±16.7 vs 89.7±11.0; P=.13) and a lower frequency (15.4% vs 35.7%; P=.38) of having a score of <85 (ie, 1 standard deviation lower than the mean) compared with those in the placebo group. Finally, there was no difference in the parents' report on the Child Behavior Checklist between the 2 groups. CONCLUSION: This study reported on the long-term neuromotor, cognitive, and behavioral outcomes among children exposed to pravastatin in utero during the second and third trimesters of pregnancy. Although the data were limited by the original trial's sample size, no identifiable long-term neurodevelopmental safety signal was evident with the use of pravastatin during pregnancy. This favorable neonatal risk-benefit analysis justifies continued research using pravastatin in clinical trials.

Optimal Timing of Delivery for Pregnant Individuals With Mild Chronic Hypertension.

OBJECTIVE: To investigate the optimal gestational age to deliver pregnant people with chronic hypertension to improve perinatal outcomes. METHODS: We conducted a planned secondary analysis of a randomized controlled trial of chronic hypertension treatment to different blood pressure goals. Participants with term, singleton gestations were included. Those with fetal anomalies and those with a diagnosis of preeclampsia before 37 weeks of gestation were excluded. The primary maternal composite outcome included death, serious morbidity (heart failure, stroke, encephalopathy, myocardial infarction, pulmonary edema, intensive care unit admission, intubation, renal failure), preeclampsia with severe features, hemorrhage requiring blood transfusion, or abruption. The primary neonatal outcome included fetal or neonatal death, respiratory support beyond oxygen mask, Apgar score less than 3 at 5 minutes, neonatal seizures, or suspected sepsis. Secondary outcomes included intrapartum cesarean birth, length of stay, neonatal intensive care unit admission, respiratory distress syndrome (RDS), transient tachypnea of the newborn, and hypoglycemia. Those with a planned delivery were compared with those expectantly managed at each gestational week. Adjusted odds ratios (aORs) with 95% CIs are reported. RESULTS: We included 1,417 participants with mild chronic hypertension; 305 (21.5%) with a new diagnosis in pregnancy and 1,112 (78.5%) with known preexisting hypertension. Groups differed by body mass index (BMI) and preexisting diabetes. In adjusted models, there was no association between planned delivery and the primary maternal or neonatal composite outcome in any gestational age week compared with expectant management. Planned delivery at 37 weeks of gestation was associated with RDS (7.9% vs 3.0%, aOR 2.70, 95% CI, 1.40-5.22), and planned delivery at 37 and 38 weeks was associated with neonatal hypoglycemia (19.4% vs 10.7%, aOR 1.97, 95% CI, 1.27-3.08 in week 37; 14.4% vs 7.7%, aOR 1.82, 95% CI, 1.06-3.10 in week 38). CONCLUSION: Planned delivery in the early-term period compared with expectant management was not associated with a reduction in adverse maternal outcomes. However, it was associated with increased odds of some neonatal complications. Delivery timing for individuals with mild chronic hypertension should weigh maternal and neonatal outcomes in each gestational week but may be optimized by delivery at 39 weeks.

Effects of Antihypertensive Therapy During Pregnancy on Postpartum Blood Pressure Control.

OBJECTIVE: To compare differences in postpartum blood pressure (BP) control (BP below 140/90 mm Hg) for participants with hypertension randomized to receive antihypertensive treatment compared with no treatment during pregnancy. METHODS: This study was a planned secondary analysis of a multicenter, open-label, randomized controlled trial (The CHAP [Chronic Hypertension and Pregnancy] trial). Pregnant participants with mild chronic hypertension (BP below 160/105 mm Hg) were randomized into two groups: active (antihypertensive treatment) or control (no treatment unless severe hypertension, BP 160/105 mm Hg or higher). Study outcomes were BP control below 140/90 mm Hg (primary) and medication nonadherence based on a composite score threshold (secondary) at the 6-week postpartum follow-up visit. Participants without follow-up BP measurements were excluded from analysis of the BP control outcome. Participants without health care professional-prescribed antihypertensives at delivery were excluded from the analysis of the adherence outcome. Multivariable logistic regression was used to adjust for potential confounders. RESULTS: Of 2,408 participants, 1,684 (864 active, 820 control) were included in the analysis. A greater percentage of participants in the active group achieved BP control (56.7% vs 51.5%; adjusted odds ratio [aOR] 1.22, 95% CI, 1.00-1.48) than in the control group. Postpartum antihypertensive prescription was higher in the active group (81.7% vs 58.4%, P<.001), and nonadherence did not differ significantly between groups (aOR 0.81, 95% CI, 0.64-1.03). CONCLUSION: Antihypertensive treatment of mild chronic hypertension during pregnancy was associated with better BP control below 140/90 mm Hg in the immediate postpartum period.

Mean Arterial Pressure and Neonatal Outcomes in Pregnancies Complicated by Mild Chronic Hypertension.

OBJECTIVE: To estimate the association between mean arterial pressure during pregnancy and neonatal outcomes in participants with chronic hypertension using data from the CHAP (Chronic Hypertension and Pregnancy) trial. METHODS: A secondary analysis of the CHAP trial, an open-label, multicenter randomized trial of antihypertensive treatment in pregnancy, was conducted. The CHAP trial enrolled participants with mild chronic hypertension (blood pressure [BP] 140-159/90-104 mm Hg) and singleton pregnancies less than 23 weeks of gestation, randomizing them to active treatment (maintained on antihypertensive therapy with a goal BP below 140/90 mm Hg) or standard treatment (control; antihypertensives withheld unless BP reached 160 mm Hg systolic BP or higher or 105 mm Hg diastolic BP or higher). We used logistic regression to measure the strength of association between mean arterial pressure (average and highest across study visits) and to select neonatal outcomes. Unadjusted and adjusted odds ratios (per 1-unit increase in millimeters of mercury) of the primary neonatal composite outcome (bronchopulmonary dysplasia, retinopathy of prematurity, necrotizing enterocolitis, or intraventricular hemorrhage grade 3 or 4) and individual secondary outcomes (neonatal intensive care unit admission [NICU], low birth weight [LBW] below 2,500 g, and small for gestational age [SGA]) were calculated. RESULTS: A total of 2,284 participants were included: 1,155 active and 1,129 control. Adjusted models controlling for randomization group demonstrated that increasing average mean arterial pressure per millimeter of mercury was associated with an increase in each neonatal outcome examined except NEC, specifically neonatal composite (adjusted odds ratio [aOR] 1.12, 95% CI, 1.09-1.16), NICU admission (aOR 1.07, 95% CI, 1.06-1.08), LBW (aOR 1.12, 95% CI, 1.11-1.14), SGA below the fifth percentile (aOR 1.03, 95% CI, 1.01-1.06), and SGA below the 10th percentile (aOR 1.02, 95% CI, 1.01-1.04). Models using the highest mean arterial pressure as opposed to average mean arterial pressure also demonstrated consistent associations. CONCLUSION: Increasing mean arterial pressure was positively associated with most adverse neonatal outcomes except NEC. Given that the relationship between mean arterial pressure and adverse pregnancy outcomes may not be consistent at all mean arterial pressure levels, future work should attempt to further elucidate whether there is an absolute threshold or relative change in mean arterial pressure at which fetal benefits are optimized along with maternal benefits. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov , NCT02299414.

Pregnancy Outcomes of Nifedipine Compared With Labetalol for Oral Treatment of Mild Chronic Hypertension.

OBJECTIVE: To evaluate maternal and neonatal outcomes by type of antihypertensive used in participants of the CHAP (Chronic Hypertension in Pregnancy) trial. METHODS: We conducted a planned secondary analysis of CHAP, an open-label, multicenter, randomized trial of antihypertensive treatment compared with standard care (no treatment unless severe hypertension developed) in pregnant patients with mild chronic hypertension (blood pressure 140-159/90-104 mm Hg before 20 weeks of gestation) and singleton pregnancies. We performed three comparisons based on medications prescribed at enrollment: labetalol compared with standard care, nifedipine compared with standard care, and labetalol compared with nifedipine. Although active compared with standard care groups were randomized, medication assignment within the active treatment group was not random but based on clinician or patient preference. The primary outcome was the occurrence of superimposed preeclampsia with severe features, preterm birth before 35 weeks of gestation, placental abruption, or fetal or neonatal death. The key secondary outcome was small for gestational age (SGA) neonates. We also compared medication adverse effects between groups. Relative risks (RRs) and 95% CIs were estimated with log binomial regression to adjust for confounding. RESULTS: Of 2,292 participants analyzed, 720 (31.4%) received labetalol, 417 (18.2%) received nifedipine, and 1,155 (50.4%) received no treatment. The mean gestational age at enrollment was 10.5±3.7 weeks; nearly half of participants (47.5%) identified as non-Hispanic Black; and 44.5% used aspirin. The primary outcome occurred in 217 (30.1%), 130 (31.2%), and 427 (37.0%) in the labetalol, nifedipine, and standard care groups, respectively. Risk of the primary outcome was lower among those receiving treatment (labetalol use vs standard adjusted RR 0.82, 95% CI, 0.72-0.94; nifedipine use vs standard adjusted RR 0.84, 95% CI, 0.71-0.99), but there was no significant difference in risk when labetalol was compared with nifedipine (adjusted RR 0.98, 95% CI, 0.82-1.18). There were no significant differences in SGA or serious adverse events between participants receiving labetalol and those receiving nifedipine. CONCLUSION: No significant differences in predetermined maternal or neonatal outcomes were detected on the basis of the use of labetalol or nifedipine for treatment of chronic hypertension in pregnancy. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, NCT02299414.

Perinatal Outcomes Associated With Management of Stage 1 Hypertension.

OBJECTIVE: To evaluate the association between maternal blood pressure (BP) below 130/80 mm Hg compared with 130-139/80-89 mm Hg and pregnancy outcomes. METHODS: We conducted a planned secondary analysis of CHAP (Chronic Hypertension and Pregnancy), an open label, multicenter, randomized controlled trial. Participants with mean BP below 140/90 mm Hg were grouped as below 130/80 mm Hg compared with 130-139/80-89 mm Hg by averaging postrandomization clinic BP throughout pregnancy. The primary composite outcome was preeclampsia with severe features, indicated preterm birth before 35 weeks of gestation, placental abruption, or fetal or neonatal death. The secondary outcome was small for gestational age (SGA). RESULTS: Of 2,408 patients in CHAP, 2,096 met study criteria; 1,328 had mean BP 130-139/80-89 mm Hg and 768 had mean BP below 130/80 mm Hg. Participants with mean BP below 130/80 mm Hg were more likely to be older, on antihypertensive medication, in the active treatment arm, and to have lower BP at enrollment. Mean clinic BP below 130/80 mm Hg was associated with lower frequency of the primary outcome (16.0% vs 35.8%, adjusted relative risk 0.45; 95% CI 0.38-0.54) as well as lower risk of severe preeclampsia and indicated birth before 35 weeks of gestation. There was no association with SGA. CONCLUSION: In pregnant patients with mild chronic hypertension, mean BP below 130/80 mm Hg was associated with improved pregnancy outcomes without increased risk of SGA. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov , NCT02299414.

Breastfeeding initiation and duration among people with mild chronic hypertension: a secondary analysis of the Chronic Hypertension and Pregnancy trial.

BACKGROUND: Increased duration of breastfeeding improves maternal cardiovascular health and may be especially beneficial in high-risk populations, such as those with chronic hypertension. Others have shown that individuals with hypertension are less likely to breastfeed, and there has been limited research aimed at supporting breastfeeding goals in this population. The impact of perinatal blood pressure control on breastfeeding outcomes among people with chronic hypertension is unknown. OBJECTIVE: This study aimed to evaluate whether breastfeeding initiation and short-term duration assessed at the postpartum clinic visit differed according to perinatal blood pressure treatment strategy (targeting blood pressure <140/90 mm Hg vs reserving antihypertensive treatment for blood pressure ≥160/105 mm Hg). STUDY DESIGN: We performed a secondary analysis of the Chronic Hypertension and Pregnancy trial. This was an open-label, multicenter, randomized trial where pregnant participants with mild chronic hypertension were randomized to receive antihypertensive medications with goal blood pressure <140/90 mm Hg (active treatment) or deferred treatment until blood pressure ≥160/105 mm Hg (control). The primary outcome was initiation and duration of breastfeeding, assessed at the postpartum clinic visit. We performed bivariate analyses and log-binomial and cumulative logit regression models, adjusting models for variables that were unbalanced in bivariate analyses. We performed additional analyses to explore the relationship between breastfeeding duration and blood pressure measurements at the postpartum visit. RESULTS: Of the 2408 participants from the Chronic Hypertension and Pregnancy trial, 1444 (60%) attended the postpartum study visit and provided breastfeeding information. Participants in the active treatment group had different body mass index class distribution and earlier gestational age at enrollment, and (by design) were more often discharged on antihypertensives. Breastfeeding outcomes did not differ significantly by treatment group. In the active and control treatment groups, 563 (77.5%) and 561 (78.1%) initiated breastfeeding, and mean durations of breastfeeding were 6.5±2.3 and 6.3±2.1 weeks, respectively. The probability of ever breastfeeding (adjusted relative risk, 0.99; 95% confidence interval, 0.93-1.05), current breastfeeding at postpartum visit (adjusted relative risk, 1.01; 95% confidence interval, 0.94-1.10), and weeks of breastfeeding (adjusted odds ratio, 0.87; 95% confidence interval, 0.68-1.12) did not differ by treatment group. Increased duration (≥2 vs <2 weeks) of breastfeeding was associated with slightly lower blood pressure measurements at the postpartum visit, but these differences were not significant in adjusted models. CONCLUSION: In a secondary analysis of the cohort of Chronic Hypertension and Pregnancy trial participants who attended the postpartum study visit and provided breastfeeding information (60% of original trial participants), breastfeeding outcomes did not differ significantly by treatment group. This suggests that maintaining goal blood pressure <140/90 mm Hg throughout the perinatal period is associated with neither harm nor benefit for short-term breastfeeding goals. Further study is needed to understand long-term breastfeeding outcomes among individuals with chronic hypertension and how to support this population in achieving their breastfeeding goals.