When Should We Induce a Normal Post-Term Pregnancy - 42 Weeks, 41 Weeks or Earlier?

Jouko Pirhonen

University Hospital of North Norway, Norway

*Correspondence to: Dr. Jouko Pirhonen, University Hospital of North Norway, Norway.

Copyright © 2019 Dr. Jouko Pirhonen. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

An upcoming article from Sweden (Swepis=Swedish post-term induction study) has been discussed widely even before it is published in the BMJ. The authors conclude that the risk for fetal demise of post-term pregnancy in week 42 compared to week 41 was so high that the study was interrupted before it was fulfilled. The final number of pregnant women in this study was 2760. Six foetuses in total died in the group of women who waited to be induced in week 42 of pregnancy (one fetus had heart failure, and another died during neonatal period).

The induction of post-term pregnancies varies between Scandinavian countries. Sweden has been more conservative, and more often Swedes wait until 42 weeks before inducing the post-term delivery. In other Scandinavian countries, most often the induction takes place earlier than in Sweden.

When this article is published, it is of interest to see why the results are as they are. Were there some other factors which could cause the difference between 41 and 42 weeks? What about risk factors? Were all the pregnancies so called normal pregnancies? And further, does the number of cesarean sections increase due to earlier induction? Induction with prostaglandins has some rare complications, such uterine rupture, especially for women with earlier cesarean delivery. A pregnancy is a completely normal situation. Why should we change the natural process? Thus, we must evaluate advantages contra disadvantages if we change the practice of induction.

The results of this study are significantly worse than in earlier studies. Further, this study was a randomised study. However, this was not necessary because the data could have been available using a longitudinal approach as well. Therefore, the easiest way to check the status in other countries is just to see the fetal demise statistics in post-term pregnancies, and you will get the exact estimate for the length of pregnancy.