Are Long Periods of Undisturbed Sleep a Cause of Stillbirth?

Researchers explore how maternal sleep habits during pregnancy may be associated with fetal health.

According to the Stillbirth Collaborative Research Network (SCRN), there are many likely causes and contributing factors to fetal deaths. A recent study, published in the journal Birth, explores how maternal sleep habits during pregnancy may impact fetal health. Researchers believe that maternal sleep studies may help them identify interventions and better advise women of potentially modifiable risk factors for stillbirths.

In the study, researchers analyzed an online survey of 153 women who had experienced a late stillbirth, as well as 480 women who were either in their third trimester or had recently given birth to a live baby. The survey’s findings suggested a link between stillbirths and mothers who slept for long, undisturbed periods. This connection appeared to be independent of other known risk factors.

Many pregnant women report disrupted sleep or waking up in the middle of the night. It appears that these disrupted sleep patterns may be a protective response.

Understanding Maternal Health and Sleep Patterns

The body’s autonomic nervous system regulates blood pressure, and low blood pressure has been linked to fetal growth problems, preterm birth, and stillbirth. Blood pressure reaches its lowest point during sleep, but surges when someone awakens. Therefore, it’s possible that when a pregnant woman wakes up, this brief increase in blood pressure may reduce her risk of stillbirth.

The researchers noted that additional studies are required to investigate the relationship between the autonomic nervous system, which regulates bodily function, and the hormonal system and how both systems are regulated during sleep in late pregnancy.

At this time, we cannot reach any conclusions about the relationship between sleep and stillbirth without more research. Additionally, very disrupted sleep has been associated with poor pregnancy outcomes. Therefore, pregnant women should not begin waking themselves at night.

Stillbirth Has Many Contributing Factors

While some grieving parents want a clear explanation for their loss, stillbirth often has many contributing factors. Sometimes, we can’t fully identify the cause of death. These are the most common causes of stillbirth:

Pregnancy and Labor Complications

Pregnancy complications, including preterm labor, pregnancy with twins or triplets, and placental abruption, when the placenta separates from the womb and fails to provide nutrients and oxygen to the fetus, likely cause one-third of all stillbirths.

Problems with the Placenta

The placenta is an organ that provides oxygen and nutrients to a fetus and removes waste products from their blood. Issues with the placenta and insufficient blood flow contribute to almost 25% of stillbirths. These deaths tend to occur after 24 weeks of pregnancy.

Birth Defects

Genetic and structural birth defects contribute to more than 10% of all stillbirths.


An infection with the fetus or placenta is a likely cause of 10 % stillbirths before week 24.

Umbilical Cord Issues

This type of stillbirth tends to occur toward the end of pregnancy when the cord can get knotted or squeezed, cutting off oxygen to the developing fetus. It is responsible for about one in ten stillbirths.

High Blood Pressure Disorders

Chronic high blood pressure or preeclampsia, pregnancy-related high blood pressure, are the cause of some stillbirths. This factor is more common toward the end of the second trimester and the beginning of the third trimester.

Maternal Complications

Health-related issues, such as diabetes, are a probable or a possible cause in fewer than one in ten stillbirths. Advanced maternal age, diabetes, obesity, smoking, and drug abuse are among well-established risk factors for stillbirths. Research also suggests that smoking tobacco or marijuana, taking prescription painkillers, or using illegal drugs during pregnancy may double or even triple the risk of stillbirth.

Statistics tell us that stillbirth affects about 1 in 160 pregnancies in the United States. That is about 24,000 stillborn babies in the country every year. According to the Centers for Disease Control and Prevention, that number is about ten times the number of sudden infant death syndrome (SIDS) deaths.

Nearly half of all stillbirths happen after 28 weeks of pregnancy, and many remained unexplained.

While many of the risk factors associated with stillbirths cannot be modified once pregnancy has begun, it is important to continue to research every potential intervention that may help prevent poor pregnancy outcomes.

Black Women Face a Higher Risk of Stillbirth

In the United States,  black women are twice as likely as white or Hispanic women to have a stillborn baby. The SCRN study noted that women who had experienced financial, emotional, traumatic, or partner-related stress during the year before their delivery were twice as likely to have a stillbirth than those who had not. Among women in general, black women are more likely to experience at least three stressful events during that time period, which may be a causal link to their higher incidences of stillbirths.

Reducing the Risk of Stillbirth

If you know the risk factors and signs to look out for, you may reduce your risk of stillbirth. To help improve you and your child’s health, Canopy Health encourages all expecting mothers to seek out high-quality prenatal care and education.

Speak to your doctor or midwife about any concerns and discuss ways you can help reduce the risk of stillbirth during pregnancy:

  • See your doctor or midwife at the recommended visitation schedule. Tests and measurements during pregnancy can help identify potential problems.
  • Eat healthily and keep active. While pregnancy is not a time to diet, being overweight or obese can increase the risk of pregnancy complications. During pregnancy, you should follow a healthy diet, including healthy snacks, and exercise.
  • Do not smoke. Stop if you already smoke. See a doctor or pharmacist about a smoking cessation program. Be mindful of passive smoking (breathing smoke from other people’s cigarettes) is also harmful in pregnancy.
  • Avoid alcohol. To ensure your baby is not harmed by alcohol, do not drink while pregnant.
  • Sleep on your side. Sleeping on your back during pregnancy doubles the risk of stillbirth after 28 weeks of pregnancy.
  • Tell your doctor or midwife about any illegal drug use. It can help you and your baby.
  • Get your seasonal flu shot. Pregnant women are more at risk for flu complications, such as bronchitis and pneumonia. The vaccine also passes some protection to your newborn during the first few months of the baby’s life.
  • Avoid sick people. When possible, avoid contact with anyone who has an infectious disease.
  • Wash your hands. Reduce the risk of infection, particularly before preparing food, after using the toilet, or changing a diaper.
  • Prepare and store food safely.
  • Avoid some foods. Unpasteurized milk, raw or undercooked meats, some cheeses are not recommended. Check with your doctor or midwife.

Moreover, if any of the following events occur, contact your doctor or midwife right away. Do not wait until the next appointment, or after the weekend, even if in the middle of the night:

  • Baby’s movements have reduced
  • Bleeding from your vagina
  • Unusual vaginal discharge
  • Blurred vision, severe headache, swelling
  • Itching, particularly on your hands and feet, could be a sign of a liver disorder, obstetric cholestasis

If you believe you may be at-risk or have experienced a stillbirth and have questions or need support or grief counseling, please seek help from your obstetrician, primary care physician, or the following resource: HAND (Helping After Neonatal Death) of the Bay Area, a local non-profit organization.


Mostavfavi, B. (2019, January 22). Long periods of undisturbed sleep may be associated with stillbirth. M Health Lab. Retrieved from

What are possible causes of stillbirth? (2016, December 1). Eunice Kennedy Shriver National Institute of Child Health and Human Development. Retrieved from

Your pregnancy and baby Guide (2018, May 21). National Health Service.Reducing the risk of stillbirth (2018, May 21). NHS. Retrieved from