BEIGH, M.; MIR, M. F.; AMIN, R.; SHAFI, S. Role of transvaginal ultrasound in predicting preterm labor in singleton pregnancies. International Journal of Reproduction, Contraception, Obstetrics and Gynecology, [S. l.], v. 7, n. 2, p. 561–565, 2018. DOI: 10.18203/2320-1770.ijrcog20180172. Disponível em: https://www.ijrcog.org/index.php/ijrcog/article/view/4052. Acesso em: 2 oct. 2025.