The purpose of this study is to evaluate whether a blood pressure treatment strategy during pregnancy to achieve targets that are recommended for non-pregnant reproductive-age adults (<140/90 mmHg) compared ACOG- recommended standard during pregnancy (no treatment unless BP is severe) is effective and safe.
1. Women with chronic hypertension in pregnancy with new or untreated chronic
hypertension, blood pressure 140-159 systolic or 90-104 diastolic OR known chronic
hypertension on monotherapy and taking any antihypertensive and blood pressure
≤159/104 (including those with blood pressure <140/90);
2. Singleton; and
3. viable pregnancy <23 weeks of gestation.
1. Blood pressures prior to randomization ≥160 systolic or ≥105 diastolic (with or
2. Patients currently treated with >1 antihypertensive medication (more likely to have
severe chronic hypertension);
3. Multi-fetal pregnancy;
4. Known secondary cause of chronic hypertension;
5. High-risk co-morbidities for which treatment may be indicated:
- Class C or higher diabetes mellitus
- Chronic kidney disease - including baseline proteinuria (>300mg/24-hr, p/c ratio
>0.3, or persistent 1+ proteinuria*) or creatinine >1.2.
*If a dipstick value at screening is more than trace, a clean catch or catheter
urine should be obtained and re-tested by dipstick. If this shows trace or
absence of protein, the patient is included. If it again shows 1+ protein, the
patient is excluded until a 24-hr urine <300mg/24hr or p/c ratio is <0.3.
- Cardiac disorders: cardiomyopathy, angina, CAD
- Prior stroke
- Sickle cell disease;
6. Known major fetal anomaly;
7. Known fetal demise;
8. Suspected IUGR;
9. Membrane rupture or planned termination prior to randomization;
10. Plan to deliver outside the consortium centers (unless approved by the Clinical
Coordinating Center) or unlikely to follow-up in the opinion of study staff or
previous participation in this trial;
11. Contraindication to labetalol or nifedipine (e.g. know hypersensitivity); and (12)
Current substance abuse or addiction (cocaine, methamphetamine) *The minimum age
varies by center