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‘Significant’ stillbirth risk in pregnancies beyond 40 weeks, study warns

Women should be informed of their increased risk of stillbirth if they continue their pregnancy beyond term, researchers have warned.

An analysis found that the risk of stillbirth increased for every week that a pregnancy continued beyond 37 weeks, with the biggest risk increases seen between 40 and 43 weeks’ gestation.

Women who continued their pregnancy to 41 weeks had a significant 64% increased risk of stillbirth compared to those who delivered at 40 weeks.

The increased risk equated to one additional stillbirth per 1,449 women who continued their pregnancy to 41 weeks.

They also found that black women were between 1.5 and two times as likely to experience stillbirth at any gestational age when compared to white women.

The research looked at the results of 13 separate studies, including over 15 million pregnancies.

The researchers said in the paper: ‘Pregnancies that continued to 41 weeks—currently still considered normal term gestation—had a small but significant increase in the risk of stillbirth compared to those delivered at 40 weeks.

‘Any discussion with women considering prolonging their pregnancy beyond 41 weeks gestation should be include information on the absolute risk increase, and the effects of induction of labour on mode of delivery and perinatal outcomes.

‘There is a need to assess the acceptability of early delivery at term to parents and healthcare providers to avoid the small risk of stillbirth.’

PLOS One 2019, online 2 Jul