Predicting nifedipine responses in preterm labor: a risk score incorporating ABCG2 polymorphisms and clinical factors

Background: Nifedipine, a substrate of ATP-binding cassette superfamily G member 2 (ABCG2), is a tocolytic agent. This study aimed to construct a scoring system by exploring the association between ABCG2 polymorphisms and the treatment response of nifedipine in pregnant women. Methods: This study was conducted at a tertiary medical center. Eight single-nucleotide polymorphisms from the ABCG2 gene were selected. The adjusted OR (AOR) were calculated using multivariable analysis. A risk scoring system was constructed by dividing the AOR of independent risk factors by the minimum AOR to predict treatment failure. Results: A total of 69 patients were analyzed for treatment failure. Maternal age ≥33 years, contraction interval <4 minutes, and contraction intensity ≥20 mmHg were clinical risk factors associated with treatment failure. Patients with the ABCG2 rs2622604 and rs4148157 experienced an 8.6-fold and 4.3-fold increased risk of treatment failure, respectively. The predicted risks of treatment failure of patients who scored 0, 1–2, 3–4, 5–6, 7–8, and 9 points were 2.8%, 9.1%, 26.0%, 55.4%, 81.4%, and 93.9%, respectively. Conclusion: This novel risk scoring system may aid clinicians in identifying patients less likely to respond to nifedipine, improving individualized care in preterm labor management.