Vanderbilt researchers believe progesterone could be the saving grace for some premature infants. Women with a known history of premature birth may reduce the risk of subsequent premature birth if progesterone is taken during the following pregnancy. Researchers studied health records from 1966 to 2011. More than 30 studies were found reporting the effects of progesterone dosed via injection, oral medication or vaginal solution. The results of the Vanderbilt study were published in Obstetrics & Gynecology via the American College of Obstetricians and Gynecologists.

Past studies included women with all sorts of medical histories. Some were pregnant with multiples and others suffered a shortened cervix, which shortened gestation, but all had experienced premature birth in a previous pregnancy. Not all women benefited from progesterone therapy. For instance, women pregnant with multiples did no experience statistically significant increases in gestation. However, some women in the study did show significant changes in pregnancy outcome though not all doctors and researchers are sold on the results.

Each pregnancy is a new experience with a new set of possible complications. There are many cases of recurrent premature labor and birth that clearly show a pattern in a particular woman’s life, but not all women who experience premature birth with one pregnancy will naturally give birth early in subsequent pregnancies. This is one of the inherent flaws in the study. There is no way of proving the progesterone affected gestational time, which is why researchers involved with the study, including lead author Dr. Frances E. Likis, believe further research is needed. “While we know that women have progesterone levels that go up in early pregnancy and remain elevated, we still don’t understand why giving extra progestogens would help them stay pregnant.”

Another problem with the study was the lack of information about infant complications or health issues that occurred after birth. Researchers need to look into the long-term consequences of progesterone treatment in the third trimester before the treatment can be considered a viable option to prevent premature birth. To research the outcome and viability of treatment, a much larger group of women need to be studied and the study needs to extend beyond birth for several years, at least, to gain a better understanding of overall benefit and outcome.


Likis FE, Edwards DR, Andrews JC, Woodworth AL, Jerome RN, Fonnesbeck CJ, McKoy JN, Hartmann KE. Progestogens for preterm birth prevention: a systematic review and meta-analysis.
Obstet Gynecol. 2012 Oct;120(4):897-907.