Treatment with vaginal progesterone may help reduce certain risks that can occur when mothers are pregnant with twins and have a short cervix, which is a risk factor for preterm birth.
The findings come from an Ultrasound in Obstetrics and Gynecology meta-analysis of 6 studies encompassing 303 women pregnant with twins, all of whom had a cervical length of 25 mm or less in the midtrimester. Of these, 159 women received vaginal progesterone and 144 received a placebo or no treatment.
Women who received vaginal progesterone were 31% less likely to deliver before 33 weeks of pregnancy (43% of those in the placebo/no treatment group versus 31% of those in the vaginal progesterone group). Vaginal progesterone also reduced the rate of preterm delivery before 32 weeks and 34 weeks.
Infants born to patients who received vaginal progesterone had a 30% reduction in the rate of respiratory distress syndrome, the most common complication of prematurity (47% in the placebo/no treatment group versus 33% in the vaginal progesterone group), a 46% reduction in the rate of mechanical ventilation (27% in the placebo/no treatment group versus 16% in the vaginal progesterone group), and a 4% reduction in the risk of dying in the neonatal period (22% in the placebo/no treatment group versus 11% in the vaginal progesterone group).
"To date, clinical practice and national recommendations to prevent preterm birth and reduce related adverse outcome in twin pregnancies vary significantly because of a lack of convincing scientific evidence and regional variation in the interpretation of said evidence," said Basky Thilaganathan, Ultrasound in Obstetrics and Gynecology's Editor-in-Chief. "The findings of this individual patient data meta-analysis provide scientific evidence that treatment with vaginal progesterone in women with a short cervix and a twin pregnancy reduces the frequency of preterm birth and related serious adverse perinatal outcomes."