Effects of nifedipine on fetal pulmonary blood flow in preterm labor

Abstract

Objective: To determine the effect of nifedipine on the fetal pulmonary system by acceleration/ejection time ratio of the fetal main pulmonary artery Doppler waveform. Methods: This prospective study was conducted in a high-risk pregnancy clinic with pregnant women who required nifedipine treatment to prevent preterm labor between 24 and 34 weeks of gestation. An ultrasound examination that included measurements of the acceleration time (AT), ejection time (ET), and AT/ET ratio (PATET) were performed before and 48 h after the first nifedipine dose. Results: Forty-three pregnant women were included in this study. AT and PATET found higher in the after nifedipine group when compared with before nifedipine group. When the ET parameters were compared, no differences were detected between the groups. Conclusion: Nifedipine increases fetal pulmonary blood flow which appears to increase AT and PATET on Doppler parameters in pregnant women with preterm labor after 48h treatment.

Özet

Amaç: Fetal ana pulmoner arter Doppler dalga formunun h›zlanma/ ejeksiyon zaman› oran›yla nifedipinin fetal pulmoner sistem üzerindeki etkisini belirlemek. Yöntem: Bu prospektif çal›flma, bir yüksek riskli gebelik klini¤inde gebeli¤in 24 ile 34. haftalar› aras›nda preterm do¤umu önlemek için nifedipin tedavisine ihtiyaç duyan gebelerle gerçeklefltirildi. ‹lk nifedipin dozundan önce ve 48 saat sonras›nda h›zlanma zaman› (AT), ejeksiyon zaman› (ET) ve AT/ET oran› (PATET) ölçümlerini içeren bir ultrason muayenesi yap›ld›. Bulgular: Bu çal›flmaya 43 gebe dahil edildi. AT ve PATET de- ¤erleri, nifedipin öncesi gruba k›yasla nifedipin sonras› grupta daha yüksek bulundu. ET parametreleri karfl›laflt›r›ld›¤›nda, gruplar aras›nda hiçbir farkl›l›k bulunmad›. Sonuç: Nifedipin fetal pulmoner kan ak›fl›n› art›rmaktad›r ve bu da, 48 saatlik tedavi sonras›nda preterm do¤um yapan gebelerde Doppler parametrelerindeki AT ve PATET de¤erlerini art›rmaktad›r.