Chronic Hypertension and Pregnancy (CHAP) Project (CHAP)

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.

Inclusion Criteria: 

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.

Exclusion Criteria:
1.Blood pressures prior to randomization ≥160 systolic or ≥105 diastolic (with or without treatment);
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
◦Retinopathy
◦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