Screening and prevention of preterm birth in twin pregnancies

Preterm birth (PTB) is commonest cause of perinatal mortality and morbidity in multiple pregnancies with significant long-term sequelae. The etiology of PTB is multifactorial. Universal screening by a transvaginal assessment of cervical length (CL) at midtrimester scan is recommended for all women with twin pregnancies. Women with CL ≤ 25 mm should be offered prophylactic vaginal progesterone to mitigate the risk of PTB. Other modalities like home uterine activity monitoring, digital cervical examination, fetal fibronectin (FFN) assessment, and screening for infections are not recommended. History-indicated cerclage is not advised in unselected twin pregnancies, but a combination of physical examination-indicated cerclage, tocolytics, and antibiotics may be considered in twin pregnancies with a dilated cervix prior to 24 weeks’ gestation. Routine use of cervical pessary is not advised and should be limited to research settings. Neither transvaginal CL nor FFN assessment is supported by evidence to predict the risk of PTB in symptomatic women with multiple pregnancies. More research is warranted to develop and validate algorithms to predict PTB to provide individualized care to these high-risk pregnancies. • Preterm birth in multiple pregnancies – multifactorial; major contributor to perinatal mortality and morbidity. • Universal screening for preterm birth is recommended by midtrimester transvaginal cervical length assessment; cutoff 25mm. • Vaginal progesterone is recommended to reduce the risk of preterm birth in twin pregnancies with cervical length ≤25mm. • Physical examination-indicated cerclage with antibiotics and tocolysis is recommended in twins with dilated cervix <24 weeks. • Cervical pessary: existing literature does not support its routine use in the prevention of preterm birth in twin pregnancies.