Study Examines Maternal Sleep and Stillbirth Risk

Understanding Stillbirth

A recent study published in the journal *Birth* explored the relationship between maternal sleep and the risk of stillbirth, defined as fetal death occurring at or after 28 weeks of pregnancy. Various factors contribute to stillbirth, including advanced maternal age, obesity, smoking, pre-eclampsia, and diabetes during pregnancy. Since stillbirth is a preventable occurrence, numerous studies have aimed to identify and mitigate risk factors.

Research Collaboration

The Study of Trends and Associated Risks for Stillbirth Consortium, in collaboration with the Star Legacy Foundation and various parental support groups, conducted this study to analyze the impact of maternal sleep habits on stillbirth risk.

Study Methodology

Researchers administered an online survey targeting two distinct groups: women who experienced stillbirth within one month prior to the survey and those in late pregnancy or who had recently given birth to a live child (within four weeks). Participants answered questions regarding their nap durations, night-time sleep length, frequency of awakenings, sleep quality, and any sleep medications used. The survey also collected data on participants’ country of origin and ethnicity (Caucasian or non-Caucasian). Exclusions were made for women under 18 years, those with multiple fetuses or congenital anomalies, and non-English speakers.

Key Findings

The study revealed that mothers with a history of stillbirth reported longer night-time sleep. The duration of daytime naps was similar between both groups. Interestingly, mothers who had experienced stillbirth reported fewer nighttime awakenings, with many indicating improved sleep quality during the last month of pregnancy. While previous research suggested that sleeping in a supine position might increase stillbirth risk, this study did not establish a similar connection.

Potential Benefits of Nighttime Awakenings

The study highlighted that sleep disturbances, such as sleep-disordered breathing and short sleep duration, can lead to complications like gestational hypertension, gestational diabetes, pre-eclampsia, fetal growth restriction, and pre-term birth. Intermittent awakenings during sleep can elevate blood pressure, which may benefit both mother and baby by improving blood flow. Conversely, prolonged uninterrupted sleep may lead to low blood pressure and hinder fetal blood circulation.

International Study Coverage

One of the strengths of this study is its international scope, although the majority of participants were Caucasian. Non-Hispanic women exhibited a higher stillbirth risk, indicating a need for further research into racial factors affecting stillbirth rates.

Study Limitations

The study faced limitations related to data collection, as mothers had to recall their sleep habits. This reliance on memory may have affected the accuracy of the data. Additionally, the absence of objective measures, such as polysomnography, limited the reliability of the findings.

Implications for Maternal Health

Co-author Louise O’Brien stated, “Our findings add to research indicating that maternal sleep plays a role in fetal wellbeing. Studies aiming to reduce stillbirths should consider maternal sleep as this is a potentially modifiable risk factor.” Understanding maternal sleep’s role could help identify effective interventions to better advise women.

Conclusion

Stillbirth has a profound emotional impact on families, and while the causes are often unknown, many are preventable. Continued research into the risk factors for stillbirth, particularly focusing on the neurohormonal mechanisms of maternal sleep, is essential for enhancing maternal and fetal health outcomes.

References

O’Brien L, Warland J, Stacey T, Heazell A, Mitchell E. Maternal sleep practices and stillbirth: Findings from an international case-control study. *Birth*. 2019; Long periods of undisturbed sleep during pregnancy may be associated with stillbirth [Internet]. EurekAlert!. 2019 [cited 14 February 2019]. Available from: https://eurekalert.org/pub_releases/2019-01/mm-u-lpo011719.php