Women are up to four times more likely to experience stillbirth if they had a stillbirth in the previous pregnancy, scientists, including one of Indian-origin, have found.
"Stillbirth is one of the most common adverse obstetric outcomes and a traumatic experience for parents," said Sohinee Bhattacharya and colleagues from the University of Aberdeen, Scotland.
"Couples who have experienced a stillbirth need to understand why it happened and want to know the risk for future pregnancies," Bhattacharya said.
Researchers undertook systematic review and meta-analysis to examine the link between stillbirth in an initial pregnancy and risk of stillbirth in a subsequent pregnancy.
They analysed thirteen cohort and 3 case-control studies from high-income countries including Australia, Scotland, the US, Denmark, Israel, the Netherlands, Norway and Sweden.
The definition of stillbirth was foetal death at more than 20 weeks' gestation or a birth weight of at least 400g.
Data was collected for 3,412,079 women. Of these, 3,387,538 (99.3 per cent) women had a previous live birth and 24,541 (0.7 per cent) women had a stillbirth in an initial pregnancy.
Stillbirths occurred in the subsequent pregnancy for 14,283 women: 606 of 24,541 (2.5 per cent) in women with a history of stillbirth and 13,677 of 3,387,538 (0.4 per cent) in women with no history.
Twelve studies assessed the risk of stillbirth in second pregnancies. Analyses showed that women who had a stillbirth in an initial pregnancy had a nearly fivefold increased risk of stillbirth in a second pregnancy.
This risk is higher than stillbirth linked with medical conditions such as diabetes or hypertension.
After adjusting for confounding factors such as maternal age, maternal smoking and level of deprivation, the increased risk was up to fourfold higher.
Pre-pregnancy counselling services should be provided to women who had a stillbirth, the researchers said, as well as advice on changing these lifestyle factors such as smoking and obesity that are both linked to an increased risk of stillbirth.
Pregnancies should be closely monitored, and antenatal interventions and care be offered at the first sign of increased risk of distress or danger, researchers added.
The study is published in The BMJ journal.
