This protocol describes a seamless Phase II/III, randomized, double-blind clinical trial evaluating the efficacy and safety of daily low-dose aspirin (81 mg) plus lansoprazole (30 mg) in pregnant individuals at high risk for preterm birth when compared to existing standard of care, identified through biomarker-enriched screening. Participants will be enrolled between 12-16+6 weeks' gestation and followed through delivery and postpartum. The primary objective is to determine whether the investigational combination reduces the incidence of preterm birth before 37 weeks of gestation compared with placebo.
Age: 18 to 45 years at the time of informed consent.
Pregnancy: Singleton intrauterine pregnancy confirmed by ultrasound.
Gestational Age: Between 12+0 and 16+6 weeks' gestation at randomization, based on first- or early second-trimester ultrasound dating.
Prior spontaneous preterm birth (<37 weeks),
Hypersensitivity / Contraindications
Known hypersensitivity, allergy, or intolerance to aspirin, other salicylates, lansoprazole, or other proton pump inhibitors (PPIs).
History of aspirin-exacerbated respiratory disease (AERD), including asthma, nasal polyps, or bronchospasm triggered by aspirin or other NSAIDs.
History of anaphylaxis or severe hypersensitivity to any component of the study drugs.