Time between pregnancies plays no part in risk of another stillbirth

Women who have experienced a stillbirth are no more likely to have another stillborn or premature baby if they fall pregnant again within one year or wait longer between pregnancies, new research led by Curtin University has found.

The research, published in The Lancet journal, examined birth records from Finland, Norway and Western Australia between 1980 and 2016 and found that a total of 14,452 births occurred after a stillbirth, with 63 per cent of women conceiving within 12 months.

Senior author Dr Gavin Pereira, from the School of Public Health at Curtin University, said previous research suggested that women needed sufficient time to recover from a previous pregnancy to reduce the risk of fetal growth restriction and preterm birth.

“The World Health Organisation recommends waiting at least two years following live birth, and at least six months following spontaneous or induced abortion to reduce the risk of adverse birth outcomes in the following pregnancy, but there is no recommendation for the waiting time following a stillbirth,” Dr Pereira said.

“By combining birth records from Finland, Norway, and Australia, we were able to examine the length of time between pregnancies after stillbirths and whether women were at greater risk of preterm birth, giving birth to smaller babies, and stillbirth in a future pregnancy.

“We found that a total of 14,452 births occurred after a stillbirth, including 4,170 from Finland, 6,761 from Norway, and 3,521 from Western Australia. Sixty-three per cent of women conceived within 12 months and this was not associated with increased risk of adverse birth outcomes in the subsequent pregnancy.”

Lead author Dr Annette Regan, also from Curtin’s School of Public Health, said this was one of the largest known international studies to investigate the effect of delaying pregnancy following a stillbirth.

“We were able to demonstrate that conception of the next child within 12 months after a stillbirth was not associated with an increased risk of adverse pregnancy outcomes. The research may have important implications for families who have experienced a stillbirth,” Dr Regan said.

“Our findings should provide reassurance to women who wish to become pregnant or unexpectedly become pregnant shortly after a stillbirth.”

The research was co-authored by researchers from the School of Public Health and the School of Nursing, Midwifery and Paramedicine at Curtin University, Telethon Kids Institute, University of Sydney, National Institute for Health and Welfare in Finland, Karolinska Institute in Sweden, University of Bristol and Bristol Medical School in the UK, and the Norwegian Institute of Public Health in Norway.

The research paper titled, ‘Association between interpregnancy interval and adverse birth outcomes in women with a previous stillbirth: an international cohort study,’ can be found online here.

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