Researchers have found that vaginal progesterone treatments can reduce the risk of preterm births, neonatal complications and fatalities in pregnant women with a short cervix or who are having twins.
According to the Centers for Disease Control and Prevention, any birth that occurs before the 37th week of pregnancy is considered preterm. Preterm births greatly increase the risk for infant death and long term disability. In 2015, preterm births accounted for roughly 1 of every 10 infants born in the United States. For women pregnant with twins, the risk of experiencing a preterm birth is five-to-six times more likely.
Researchers at the National Institutes of Health, the Wayne State University School of Medicine, the Detroit Medical Center, and other institutions in the United States and abroad worked together on a meta-analysis of individual patient data to study the effects of vaginal progesterone treatments on the rate of preterm delivery for over 300 women.
Progesterone is a hormone released by the female body after ovulation, during the latter half of the menstrual cycle. The hormone helps to sustain a pregnancy after the egg has been fertilized.
There are different methods of progesterone supplementation including injection, vaginal insertion of gels or suppositories and oral capsules. Progesterone injections are generally given in the buttocks with a syringe and needle once daily. This process typically results in high levels of progesterone in your blood.
Vaginal insertions of a gel, a tablet, or a suppository can occur anywhere from one to three times daily. Vaginal gel is available in pre-filled applicators – the gel coats the walls of the vagina, resulting in a controlled, steady release of progesterone. Vaginal progesterone suppositories are placed into the vagina two or three times a day as are vaginal tablets. Oral progesterone capsules can result in side effects such as bloating, drowsiness, irritability and nausea.
In the new study, published in Ultrasound in Obstetrics and Gynecology, looked at women who were pregnant with twins, all of whom had a cervical length of 25 mm or less in the mid-trimester. Of these women, 159 were given vaginal progesterone and 144 were given a placebo or no treatment. Women who received the vaginal progesterone were 31 percent less likely to deliver before 33 weeks of pregnancy. Infants born to these patients who received vaginal progesterone were found to have a reduction in the rate of respiratory distress syndrome, in the rate of mechanical ventilation and in the risk of dying in the neonatal period.
“The findings represent persuasive evidence that treatment with vaginal progesterone in women with a short cervix and a twin gestation reduces the frequency of preterm birth, neonatal complications such as respiratory distress syndrome, and importantly, neonatal death,” said one of the study’s authors, Roberto Romero, M.D., chief of the Perinatology Research Branch of the Eunice Kennedy Shriver National Institute of Child Health and Human Development.
This study is the first intervention to successfully address preterm birth and could greatly impact the rate of babies born too soon.