No significant difference in complications in pregnant women with high blood pressure

Prematurely inducing labour in pregnant women with high blood pressure or pre-eclampsia between 34 and 37 weeks of pregnancy does not lead to fewer complications for this group as compared to inducing labour at 37 weeks. Premature delivery does, however, lead to more frequent respiratory problems in newborns. These are the results of a study led by UMCG researchers of more than 700 women in 51 hospitals in the Netherlands. Their findings have been published in the leading medical journal The Lancet.

Ten percent of pregnant women suffer from high blood pressure or high blood pressure combined with protein in the urine (pre-eclampsia). This can lead to potentially life-threatening complications for mother and child. The question is whether it is better to immediately induce labour to prevent these complications from developing, or to wait and induce at 37 weeks, thus eliminating the risk of complications from premature birth for the child.

Gynaecologists from 51 hospitals in the Netherlands invited their pregnant patients suffering from high blood pressure to take part in the study. More than 700 women responded and were randomly assigned to a ‘waiting’ group or an ‘induced labour’ group. Labour was also induced earlier in patients in the ‘waiting’ group if this was deemed a medical necessity.

The study shows that the risk of complications for the mother as a result of waiting is lower than expected, and that the difference between the two groups is not significant enough to draw conclusions (three percent of the pregnant women who waited suffered complications versus one percent of the pregnant women who were induced). However, newborns in the group that was induced early suffered more respiratory problems (six percent) than those in the group that waited until 37 weeks (two percent). The researchers therefore conclude that women with high blood pressure or pre-eclampsia between 34 and 37 weeks of pregnancy can safely wait, unless they need to be induced because mother or child are too ill to wait until 37 weeks.

According to the researchers, follow-up studies should focus on determining the best indications for delivery for women with high blood pressure or pre-eclampsia between 34 and 37 weeks of pregnancy. ‘Our study shows that inducing early labour in all women with high blood pressure or pre-eclampsia between 34 and 37 weeks offers too little benefit to justify the negative consequences of a premature birth for the child,’ says Kim Broekhuijsen, clinical researcher at the UMCG. ‘But if we can predict which women are likely to suffer complications, we can induce this particular group earlier while allowing other women to safely proceed with their pregnancy until 37 weeks. In this way we can prevent complications from high blood pressure without inducing unnecessary premature births.’

The participating gynaecologists are members of the Dutch Consortium for Healthcare Evaluation and Research in Obstetrics and Gynaecology. The study was coordinated by the UMCG and conducted over a period of four years.

Link to the publication: http://www.thelancet.com/journals/lancet/article/PIIS0140-6736(14)61998-X/abstract

More information on the study and the consortium of gynaecologists:

http://www.studies-obsgyn.nl/home/page.asp?page_id=326

http://www.studies-obsgyn.nl/hypitat2/page.asp?page_id=641

http://www.watverwachtu.nl/page.asp?page_id=68