Paper: Subsequent pregnancy outcome after previous foetal death
Paper authors: JW Nijkampa, FJ Kortewega, JP Holma et al
Paper ref: 166 (2013) 37-42
When pregnancy ends in still birth it’s not only agonising for the parents at the time but also in subsequent pregnancies. Studies have reported that these women are at a zero to 20-fold increased risk of a subsequent foetal death or complication. To improve counselling for these parents and provide a reason for this devastating event, and to optimise care during subsequent pregnancies, it is imperative to know the underlying cause of the foetal death.
Current studies to date have lacked detail of the cause of death in either the first foetal death (the index still birth) or the subsequent adverse outcome pregnancy, largely due to using a number of classification systems and no uniformity in data collection. The need for this data was identified by a tertiary centre in the Netherlands who have recently published a retrospective cohort study.
The study included women with a still birth past 16 weeks gestation between January 1999 and December 2004. The study uses the Tulip classification to evaluate pregnancy outcomes; this includes comparing cause of death, contributing risk factors and co-morbidities in order to try to describe relationships between the index foetal death and subsequent foetal deaths. The report included 163 women, and the results revealed that the causes of the index foetal deaths were due to the following causes: congenital anomaly (15.3 percent), placental causes (47.8 percent), prematurity/immaturity (8.6 percent), infection (2.5 percent), other (4.3 percent), and unknown (21.5 percent).
Of the women in the study, 28 didn’t go on to have a subsequent pregnancy, 16 had a miscarriage before 16 weeks. One hundred and thirteen went on to have an ongoing single pregnancy and six went on to have a twin pregnancy. Subsequent pregnancy outcomes were analysed for 125 of these women.
From the ongoing subsequent pregnancies, seven went on to have a foetal death between 17-22 weeks gestation, five had a foetal death after 22 weeks, with the rest of the cohort going on to have a living child at 28 days. The 11 subsequent foetal deaths from the ongoing pregnancies were due to placental pathology (four), prematurity (three), congenital abnormality (one), and due to unknown causes despite investigations (three).
This study is limited due to its small sample size. With the small amount of data, however, the authors have reported that there appears to be a relationship between cause of death in the 11 index pregnancies and the cause of death in the subsequent pregnancy. However, to comment on significant causal-related associations, much larger numbers are needed.
This study highlights the need for clinicians to use a uniformed classification system for recording cause of foetal deaths, gaining autopsy and placental examinations. This would provide a greater insight into pathophysiological pathways leading to foetal death. It would also facilitate counselling, as well as informing these parents and tailoring subsequent antenatal care appropriately with the aim to ultimately reduce the risk of subsequent foetal deaths.