The relationship between active/passive smoking and spontaneous preterm birth: Data from a multicenter study.

Background: Prematurity is considered to be the leading cause of death in children under 5 years of age, with one child dying every 2 s. Smoking is known to be one of the factors associated with prematurity, with both immediate and late consequences. However, it is difficult to obtain concrete data on the relationship between smoking and spontaneous preterm birth.

Association between cervical length and gestational age at birth in singleton pregnancies: a multicentric prospective cohort study in the Brazilian population.

Background: Short cervical length measured during the second trimester of pregnancy is an important risk factor for spontaneous preterm birth (sPTB). The aim of this study is to identify the association between mid-pregnancy cervical length (CL) and gestational age at birth in asymptomatic singleton pregnant women.

Methods: This is a prospective cohort study involving singleton pregnant women who participated in the screening phase of a Brazilian multicenter randomized controlled trial (P5 trial) between July 2015 and March 2019.

Cervical length distribution among Brazilian pregnant population and risk factors for short cervix: A multicenter cross-sectional study.

Objective: Since there are populational differences and risk factors that influence the cervical length, the aim of the study was to construct a populational curve with measurements of the uterine cervix of pregnant women in the second trimester of pregnancy and to evaluate which variables were related to cervical length (CL) ≤25 mm.

Materials And Methods: This was a multicenter cross-sectional study performed at 17 hospitals in several regions of Brazil. From 2015 to 2019, transvaginal ultrasound scan was performed in women with singleton pregnancies at 18 0/7 to 22 6/7 weeks of gestation to measure the CL.

Perinatal Outcomes and Factors Associated with Ethnic Group in cases of Preterm Birth: the Multicenter Study on Preterm Birth in Brazil.

Objective:  To investigate the characteristics of women who had preterm birth (PTB) and related outcomes according to ethnicity.

Methods:  A secondary analysis of a multicenter cross-sectional study conducted in Brazil. Women who had PTB were classified by self-report as white and non-white.

Pessary Plus Progesterone to Prevent Preterm Birth in Women With Short Cervixes: A Randomized Controlled Trial.

Objective: To test the effectiveness of cervical pessary in addition to vaginal progesterone for the prevention of preterm birth in women with midpregnancy short cervixes.

Methods: We performed a multicenter, open-label, randomized controlled trial in 17 perinatal centers. Asymptomatic women with singleton or twin pregnancies and cervical lengths of 30 mm or less, measured at 18 0/7-22 6/7 weeks of gestation, were randomized to cervical pessary plus vaginal progesterone (pessary plus progesterone group) or vaginal progesterone only (progesterone-only group) (200 mg/day).