Less-tight versus tight control of hypertension in pregnancy

Diana Lee, PharmD Candidate 2015 Mercer University College of Pharmacy

Hypertension during pregnancy occurs in approximately 10% of all pregnant women. Gestational and preexisting hypertension before 34 weeks are associated with an increased risk of perinatal and maternal complications, such as intracerebral hemorrhage, poor fetal growth and well-being. The treatment of severe hypertension during pregnancy (>160/110 mm Hg) is considered to be well established. However, the benefit of antihypertensive therapy for mild-to-moderately elevated blood pressure (< 160/110) have not been demonstrated.1

Title: Less-tight versus tight control of hypertension in pregnancy2
Design Open, multicenter, international, randomized, controlled trial
Objective To compare less-tight control with tight control of nonproteinuric, nonsevere hypertension in pregnancy with respect to perinatal and maternal outcomes
Study Groups Women at 14 weeks 0 days to 33 weeks 6 days of gestation who had nonsevere, nonproteinuric preexisting or gestational hypertension, office diastolic blood pressure of 90 to 105 mmHg and a live fetus were divided into less-tight control (target diastolic blood pressure (DBP), 100 mm Hg) group and tight control (target DBP, 85 mm Hg) group.
Methods Patients were randomly assigned in a 1:1 ratio to less-tight control (n=493) or tight control (n=488) until delivery. Data on blood-pressure measurements performed in an outpatient setting and cointerventions (e.g., clinic visits and fetal ultrasound examinations) were collected from the patient’s diaries at 14 to 20, 21 to 28, 29 to 33, and 34 to 40 weeks of gestation and at delivery. Outcome data was obtained from maternal and infant charts. A maternal questionnaire was also administered when the baby was at least 36 weeks to identify post discharge maternal or neonatal complications.
Duration 36 weeks
Primary Outcome Measure Composite of pregnancy loss or high-level neonatal care for more than 48 hours during the first 28 postnatal days or discharge.
Baseline Characteristics The median maternal age at expected date of delivery was approximately 34 years of age with a little less than half having a body-mass index of 30 or greater. About 33% were nulliparous and had an average 24 weeks of gestation.   Approximately ¾ had preexisting hypertension with the other ¼ having gestational hypertension.
Results Pregnancy loss occurred in three percent of the patients (15/493) in the less-tight control group and 2.7% (13/488) in the tight-control group (OR 1.14; 95% CI 0.53 to 2.45). Patients receiving high-level neonatal care for >48 hours was 29.4% (141/480) in the less-tight control group and 29% (139/479) in the tight control group (OR 1.00; 95% CI 0.75 to 1.33).
Adverse Events Common Adverse Events: Not reported
Serious Adverse Events: Not reported
Percentage that Discontinued due to Adverse Events: Not reported
Study Author Conclusions We found no significant between-group differences in the risk of pregnancy loss, high-level neonatal care, or overall maternal complications, although less-tight control was associated with a significantly higher frequency of severe maternal hypertension.

Based on this study alone, either tight-control or less-tight control does not seem to be more beneficial than the other. Although this trial was a larger trial than previous studies, this particular trial does not seem to provide much clarity to the existing literature for the treatment of hypertension in pregnancy. Physicians should use their professional judgment and carefully monitor their patients until we have clearly established hypertension treatment benefit verse risk in this patient population.

References:

  1. Podymow T, August P. Update on the use of antihypertensive drugs in pregnancy. Hypertension. 2008;51:960-969.
  2. Magee LA, Dadelszen PV, Rey E, et al. Less-tight versus tight control of hypertension in pregnancy. N Engl J Med. 2015;372(5):407-416.
Advertisements

One thought on “Less-tight versus tight control of hypertension in pregnancy

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s