Associations between social and behavioural factors and the risk of late stillbirth - findings from the Midland and North of England Stillbirth case-control study.

OBJECTIVE: To investigate behavioural and social characteristics of women who experienced a late stillbirth compared with women with ongoing live pregnancies at similar gestation. DESIGN: Case-control study. SETTING: 41 maternity units in the UK. POPULATION: Women who had a stillbirth ≥28 weeks' gestation (n = 287) and women with an ongoing pregnancy at the time of interview (n = 714). METHODS: Data were collected using an interviewer-administered questionnaire which included questions regarding women's behaviours (e.g. alcohol intake and household smoke exposure) and social characteristics (e.g. ethnicity, employment, housing). Stress was measured by the 10-item Perceived Stress Scale. MAIN OUTCOME MEASURE: Late stillbirth. RESULTS: Multivariable analysis adjusting for co-existing social and behavioural factors showed women living in the most deprived quintile had an increased risk of stillbirth compared with the least deprived quintile (adjusted odds ratio [aOR] 3.16; 95% CI 1.47-6.77). There was an increased risk of late stillbirth associated with unemployment (aOR 2.32; 95% CI 1.00-5.38) and women who declined to answer the question about domestic abuse (aOR 4.12; 95% CI 2.49-6.81). A greater number of antenatal visits than recommended was associated with a reduction in stillbirth (aOR 0.26; 95% CI 0.16-0.42). CONCLUSIONS: This study demonstrates associations between late stillbirth and socio-economic deprivation, perceived stress and domestic abuse, highlighting the need for strategies to prevent stillbirth to extend beyond maternity care. Enhanced antenatal care may be able to mitigate some of the increased risk of stillbirth. TWEETABLE ABSTRACT: Deprivation, unemployment, social stress & declining to answer about domestic abuse increase risk of #stillbirth after 28 weeks' gestation.

Gestational diabetes and the risk of late stillbirth: a case-control study from England, UK.

OBJECTIVE: To explore the separate effects of being 'at risk' of gestational diabetes mellitus (GDM) and screening for GDM, and of raised fasting plasma glucose (FPG) and clinical diagnosis of GDM, on the risk of late stillbirth. DESIGN: Prospective case-control study. SETTING: Forty-one maternity units in the UK. POPULATION: Women who had a stillbirth ≥28 weeks of gestation (n = 291) and women with an ongoing pregnancy at the time of interview (n = 733). METHODS: Causal mediation analysis explored the joint effects of (i) 'at risk' of GDM and screening for GDM and (ii) raised FPG (≥5.6 mmol/l) and clinical diagnosis of GDM on the risks of late stillbirth. Adjusted odds ratios (aOR) were estimated by logistic regression adjusted for confounders identified by directed acyclic graphs. MAIN OUTCOME MEASURES: Screening for GDM and FPG levels RESULTS: Women 'at risk' of GDM, but not screened, experienced 44% greater risk of late stillbirth than those not 'at risk' (aOR 1.44, 95% CI 1.01-2.06). Women 'at risk' of GDM who were screened experienced no such increase (aOR 0.98, 95% CI 0.70-1.36). Women with raised FPG not diagnosed with GDM experienced four-fold greater risk of late stillbirth than women with normal FPG (aOR 4.22, 95% CI 1.04-17.02). Women with raised FPG who were diagnosed with GDM experienced no such increase (aOR 1.10, 95% CI 0.31-3.91). CONCLUSIONS: Optimal screening and diagnosis of GDM mitigate the higher risks of late stillbirth in women 'at risk' of GDM and/or with raised FPG. Failure to diagnose GDM leaves women with raised FPG exposed to avoidable risk of late stillbirth. TWEETABLE ABSTRACT: Risk of #stillbirth in gestational diabetes is mitigated by effective screening and diagnosis.

Association between maternal sleep practices and late stillbirth - findings from a stillbirth case-control study.

OBJECTIVE: To report maternal sleep practices in women who experienced a stillbirth compared with controls with ongoing live pregnancies at similar gestation. DESIGN: Prospective case-control study. SETTING: Forty-one maternity units in the United Kingdom. POPULATION: Women who had a stillbirth after ≥ 28 weeks' gestation (n = 291) and women with an ongoing pregnancy at the time of interview (n = 733). METHODS: Data were collected using an interviewer-administered questionnaire that included questions on maternal sleep practices before pregnancy, in the four weeks prior to, and on the night before the interview/stillbirth. MAIN OUTCOME MEASURES: Maternal sleep practices during pregnancy. RESULTS: In multivariable analysis, supine going-to-sleep position the night before stillbirth had a 2.3-fold increased risk of late stillbirth [adjusted Odds Ratio (aOR) 2.31, 95% CI 1.04-5.11] compared with the left side. In addition, women who had a stillbirth were more likely to report sleep duration less than 5.5 hours on the night before stillbirth (aOR 1.83, 95% CI 1.24-2.68), getting up to the toilet once or less (aOR 2.81, 95% CI 1.85-4.26), and a daytime nap every day (aOR 2.22, 95% CI 1.26-3.94). No interaction was detected between supine going-to-sleep position and a small-for-gestational-age infant, maternal body mass index, or gestational age. The population-attributable risk for supine going-to-sleep position was 3.7% (95% CI 0.5-9.2). CONCLUSIONS: This study confirms that supine going-to-sleep position is associated with late stillbirth. Further work is required to determine whether intervention(s) can decrease the frequency of supine going-to-sleep position and the incidence of late stillbirth. TWEETABLE ABSTRACT: Supine going-to-sleep position is associated with 2.3× increased risk of stillbirth after 28 weeks' gestation. PLAIN LANGUAGE SUMMARY: Stillbirth, the death of a baby before birth, is a tragedy for mothers and families. One approach to reduce stillbirths is to identify factors that are associated with stillbirth. There are few risk factors for stillbirth that can be easily changed, but this study is looking at identifying how mothers may be able to reduce their risk. In this study, we interviewed 291 women who had a stillbirth and 733 women who had a live-born baby from 41 maternity units throughout the UK. The mothers who had a stillbirth were interviewed as soon as practical after their baby died. Mothers who had a live birth were interviewed during their pregnancies at the same times in pregnancy as when the stillbirths occurred. We did not interview mothers who had twins or who had a baby with a major abnormality. Mothers who went to sleep on their back had at least twice the risk of stillbirth compared with mothers who went to sleep on their left-hand side. This study suggests that 3.7% of stillbirths after 28 weeks of pregnancy were linked with going to sleep lying on the back. This study also shows that the link between going-to-sleep position and late stillbirth was not affected by the duration of pregnancy after 28 weeks, the size of the baby, or the mother's weight. Women who got up to the toilet once or more at night had a reduced risk of stillbirth. This is the largest of four similar studies that have all shown the same link between the position in which a mother goes to sleep and stillbirth after 28 weeks of pregnancy. Further studies are needed to see whether women can easily change their sleep position in late pregnancy and whether changing the position a mother goes to sleep in reduces stillbirth.