Response to Anti-hypertensives in Pregnant and Postpartum Patients

Hypertensive disease in pregnancy is a major cause of maternal morbidity and mortality. This condition is responsible for about 12% of the maternal deaths in the United States.

Currently, if pregnant patients present with severe hypertension they are either given IV labetalol, IV hydralazine of nifedipine based on individual provider preference. There are few studies in the literature comparing oral nifedipine and IV labetalol with mixed data showing either they are equally effective or a faster time to achieving target blood pressure for patients who received nifedipine.

In this study, the investigators will evaluate if there is a difference in time to achieve goal blood pressure in pregnant and postpartum patients who are treated with nifedipine and labetalol for severe range blood pressures defined as greater than 160/110. These anti-hypertensives are first line therapy for management of severe range blood pressures in pregnancy and postpartum by the American Congress of Obstetricians and Gynecologist (ACOG).

• Nifedipine (Drug): Nifedipine 10mg oral will be given and the MAP will then be calculated 20 minutes after medication is given. If SBP is ≥160mmHg or DBP is ≥110mmHg, nifedipine 20mg oral will be given and the MAP will then be calculated 20 minutes after medication is given. If SBP is ≥160mmHg or DBP is ≥110mmHg, nifedipine 20mg oral will be given and the MAP will then be calculated 20 minutes after medication is given and institution specific protocol will be performed.
• Labetalol (Drug): Labetalol 20mg IV will be given over 2 minutes and the MAP will then be calculated 10 minutes after medication is given. If SBP is ≥160mmHg or DBP is ≥110mmHg, labetalol 40mg IV will be given over 2 minutes and the MAP will then be calculated 10 minutes after medication is given. If SBP is ≥160mmHg or DBP is ≥110mmHg, labetalol 80mg IV will be given over 2 minutes and the MAP will then be calculated 10 minutes after medication is given. If SBP is ≥160mmHg or DBP is ≥110mmHg, then another medication will be chosen based on institution specific protocol.

Primary outcomes

• Time to Achieve Non Severe Range Blood Pressure [Ten minute intervals from the time of the first severe range blood pressure, up to 1 hour]: Time to achieve goal blood pressure, that is, non severe range blood pressures after medication received.
• Number of Participants to Achieve Non Severe Range Blood Pressure [up to 1 hour]: Number of participants by ethnicity to achieve goal blood pressure, that is, non severe range blood pressures after medication received.

Secondary outcomes

• Frequency of Genetic Variants of Genes [up to 1 year]: the frequency of variant alleles in different receptors involved in the response to labetalol and nifedipine administration in the pregnant and postpartum population.
• Number of Participants With Medication Side Effects [assessed 10 minutes to 1 hour after medication is given]: Number of participants with side effect profile to assess the rate of side effects from IV labetalol and oral nifedipine

Sex: Female, ages: 18 Years to 55 Years, accepts healthy volunteers

Inclusion Criteria:

* pregnant patients from 20 weeks to up to 6 weeks postpartum
* between the ages of 18-55.
* persistent severe range blood pressures (2 readings or more within 15 minutes) of either 160mmHg systolic or 110mmHg diastolic.

Exclusion Criteria:

* multiple gestation
* patients with non-reassuring fetal heart rate (category 3)
* patients with abruptio placenta
* patients with renal impairment
* history of heart failure
* history of cardiac arrhythmia
* use of anti-hypertensive medications in the past 24 hours
* patients with allergies or medical contraindications to labetalol or nifedipine.

Participant flow

Outcome results

• Time to Achieve Non Severe Range Blood Pressure (Primary), Median, minutes: Intravenous Labetalol 10 (10 to 20); Oral Nifedipine 20 (20 to 30)
• Number of Participants to Achieve Non Severe Range Blood Pressure (Primary), Count of participants, Participants: Intravenous Labetalol 33; Oral Nifedipine 31
• Frequency of Genetic Variants of Genes (Secondary)
• Number of Participants With Medication Side Effects (Secondary), Count of participants, Participants: Intravenous Labetalol 6; Oral Nifedipine 10

Adverse events

Time frame: 1 hour

Other adverse events by term

Limitations and caveats: Small sample size and the study was not double blind

• Study Protocol and Statistical Analysis Plan (PDF, 2017-11-01)

• Lois Brustman, MD, Study director, Icahn School of Medicine at Mount Sinai
• Howard Minkoff, MD, Study director, Icahn School of Medicine at Mount Sinai
• Poroshat Shekarloo, MD, Principal investigator, Icahn School of Medicine at Mount Sinai