Sweden has cancelled a major study of women whose pregnancy continued beyond 40 weeks after six babies died. The Guardian reports that the research was halted a year ago after five stillbirths and one early death in the babies of women allowed to continue their pregnancies into week 43. “Our belief is that it would not have been ethically correct to proceed” with the study, the researchers concluded.
The report says there is no international consensus on how to manage healthy pregnancies lasting more than 40 weeks, although it is generally accepted that there is an increased risk of adverse effects for mother and baby beyond 41 weeks. But because the risks are small, research into late-term pregnancies requires large numbers of women in order to achieve statistical significance. Led by University of Gothenburg’s Sahlgrenska University Hospital, the Swedish post-term induction study (Swepis) set out to survey 10,000 women at 14 hospitals.
The report says women in their 40th week of pregnancy were invited to join the study and divided randomly into two groups, with labour induced at the beginning of either week 42 or week 43, unless it occurred spontaneously.
When abruptly halted in October 2018, the study had involved only a quarter of the target number of expectant mothers. But the six deaths were already judged to indicate a significantly increased risk for women induced at the start of week 43. No infants died in the group whose pregnancies were ended a week earlier.
The report says although concern about the findings was first reported by Swedish television in the summer, researchers have declined to make the results public, or to speak to the media, until their work is published in a medical journal. But details are contained in a doctoral thesis by one of the researchers, recently made available on Gothenburg University’s website.
The immediate consequences of the study “may be a change of the clinical guidelines to recommend induction of labour no later than at 41+0 gestational weeks”, its author concludes.
Sahlgrenska hospital announced that it would change its pregnancy management policies based on the results of Swepis trial.The Guardian report Gothenburg University material