Aspirin to Prevent Preeclampsia in Women With Elevated Blood Pressure and Stage 1 Hypertension (ASPPIRE)

To determine if low dose aspirin reduces the incidence of hypertensive disorders of pregnancy (gestational hypertension, preeclampsia, eclampsia, and HELLP syndrome) in pregnant women with stage 1 hypertension and elevated blood pressure.

Inclusion Criteria:

• Singleton pregnancy
• Elevated blood pressure (At least 2 systolic BP 120-129 mm Hg within 1 year pre-pregnancy until 20 weeks gestational age on at least 2 separate healthcare encounters) or Stage 1 hypertension (At least 2 systolic BP 130-139 and/or diastolic BP 80-89 within 1 year pre-pregnancy until 20 weeks gestational age on at least 2 separate healthcare encounters)
• Speaks English or Spanish
• Informed and written consent
• Confirmed single live intrauterine pregnancy (confirmed by positive cardiac motion by transvaginal or transabdominal ultrasound)

Exclusion Criteria:

• Chronic hypertension
• Pre-gestational diabetes
• Chronic renal disease

  - diagnosis of stage 1 chronic kidney disease or higher and/or GFR <60 mL/min with duration at least 3 months and/or history of kidney transplantation and/or undergoing peritoneal or hemodialysis

• Systemic lupus erythematous
• Antiphospholipid antibody syndrome (diagnosis made by having 1 or more clinical criteria and 1 or more laboratory criteria)
  • Clinical criteria: venous thrombosis, arterial thrombosis, obstetric complications (3 or more unexplained consecutive spontaneous abortions <10 weeks gestation, 1 or more unexplained deaths of a morphologically normal fetus after 10 weeks gestation, 1 or more premature births before 34 weeks gestation attributable to placental insufficiency, including severe preeclampsia or fetal growth restriction)
  • Laboratory criteria: lupus anticoagulant, anti-cardiolipin IgG or IgM with titer >99th percentile, anti-beta 2 glycoprotein IgG or IgM with titer >99th percentile. Laboratory result must be positive twice at least 12 weeks apart
• Multifetal gestation
• 20 weeks gestation at time of randomization based on American College of Obstetricians and Gynecologists dating criteria. Dating will be based on last menstrual period (LMP) if regular, sure LMP is available that agrees with ultrasound dating. Otherwise, earliest ultrasound will be used for dating purposes.
• Prior history of hypertensive disorder of pregnancy
• Current pregnancy with known chromosomal, genetic, major malformations or fetal demise, or planned termination of pregnancy
• Women with contraindications to taking aspirin (bleeding diathesis such as Von Willebrand's disease, peptic ulcer disease, aspirin hypersensitivity, nasal polyps, asthma with aspirin-induced bronchospasm, severe liver disease).
• Concurrent participation in another study that influences risk of preeclampsia
• Women who do not plan to deliver within the YNHH system