Women who experience a pregnancy loss in their second trimester are at increased risk of complications during future pregnancies, according to new research from the University of Aberdeen.
Experts say the findings highlight an urgent need for more research, clearer clinical guidance, better follow-up care and dedicated support pathways for women affected by second trimester pregnancy loss (STPL).
Despite the serious physical and emotional impact of STPL, there are currently no national UK guidelines setting out how best to manage care in future pregnancies. Researchers say this gap leaves women and clinicians without consistent advice on monitoring, prevention strategies and specialist referral - and that standardised care pathways, similar to those introduced after stillbirth, are now needed to reduce risk and improve outcomes.
Researchers found during the pregnancy following an initial STPL, spontaneous premature birth, another second trimester loss, early miscarriage and pre-eclampsia are all more likely to occur. Whilst the overall risk remains small, and women should be reassured, the findings do suggest that there is a greater risk compared to women who had not had a previous STPL.
The study, published in BJOG: An International Journal of Obstetrics & Gynaecology, was funded by Tommy’s, the pregnancy and baby charity. The team of researchers from the University of Aberdeen and Tommy’s Maternal and Fetal Health Research Centre at the University of Manchester investigated whether STPL or termination for medical reasons (TFMR) were associated with future adverse pregnancy outcomes.
Led by Dr Andrea Woolner, Senior Clinical Lecturer at the University of Aberdeen and Honorary Consultant Obstetrician & Early Pregnancy Lead at NHS Grampian, the team examined data from 65,592 women from Aberdeen with first and second pregnancies recorded from 1950 to 2017.
The findings showed that women who had a STPL in their first pregnancy were at significantly greater risk of spontaneous premature birth in the next pregnancy (4.3% compared with 1.5%). Women with STPL in their first pregnancy were also twice as likely to have another second trimester loss (3.7% compared with 1.1%) though researchers offer reassurance that the overall risk remains low.
Women who had an initial STPL were also found to be more likely to have an early miscarriage (8.7% compared with 5%) and were more than twice as likely to have pre-eclampsia in their second pregnancy (23.4% compared with 11.7%).
Women who had a TFMR in their first pregnancy were however not at higher risk of having a spontaneous premature birth after a TFMR.
The researchers say this is reassuring for women who have had a TFMR, but because the study included a small number of people, more research is needed.
The authors say it is vital that future research is aimed at understanding why the initial loss has occurred and whether these different pathological processes explain the reasons for adverse outcomes in future pregnancies.
Dr Woolner said: “Women who have a loss in the second trimester are at greater risk of premature birth, another second trimester loss and other adverse pregnancy outcomes. This is similar to previous evidence for women who have had a stillbirth before, women with placental conditions such as pre-eclampsia and also women who have had recurrent miscarriages.
“We need to consider how women with a history of STPL are looked after in future pregnancies and carry out more research to determine the pathophysiology of STPL, so the risk can be mitigated in the first place but also in the next pregnancy.”
She suggests that as a result of the increased risks identified, “offering specialist premature birth clinics or dedicated pregnancy loss clinics for future antenatal care might be appropriate but we need further evidence to guide best practice.”
“Women who have had a second trimester loss should be counselled that they have a higher risk of complications, including premature birth. However, the overall risk is still low, and the available evidence is limited,” Dr Woolner added.
“I’d like to reassure women that the risks we have identified are still small – the majority of women won’t develop complications after a second trimester loss, but importantly, we have identified this is a high-risk group so that future research and care can be planned accordingly.”
Professor Alex Heazell, Director of Tommy’s Maternal and Fetal Health Research Centre says: “This study adds to a growing body of data that a prior pregnancy loss or stillbirth is associated with a higher risk of problems in a future pregnancy. We think this is because some causes of pregnancy loss can recur. We need further research to show whether specialist care and treatment in future pregnancies can reduce this risk.”
Dr Jyotsna Vohra, Director of Research, Programmes and Impact at Tommy’s, said: “Women and birthing people experiencing pregnancy or hoping to conceive again after a previous loss inevitably face anxiety and uncertainty.
“These findings show we need to offer families in this situation the best possible care and support, at the same time as driving forward research to understand how we can prevent the heartbreak of pregnancy and baby loss for more people.”