It’s a common piece of advice given to expectant mothers: when you’re pregnant, especially in your later months, you should always sleep on your left side. But what if you find yourself drifting to your right side? Or maybe you just can’t get comfortable on your left? Many pregnant women worry if sleeping on their right side could harm their baby. So, why can’t I sleep on my right side while pregnant, and is it really that bad if you do? New research offers some reassuring answers, especially for early and mid-pregnancy.
Concerns about sleeping positions during pregnancy often stem from the idea that certain positions might restrict blood flow, potentially impacting both mother and baby. Let’s delve into what the science says and what you actually need to consider about your sleep posture during pregnancy.
Understanding the Concerns: Why the Left Side Recommendation?
The recommendation to sleep on the left side during pregnancy is not arbitrary. It’s rooted in the anatomy of the pregnant body and the major blood vessels within it. The theory is that sleeping on your back or right side in later pregnancy could put pressure on the inferior vena cava, a large vein that carries blood back to your heart from your lower body. Similarly, pressure could be placed on the aorta, the main artery carrying blood from your heart to the rest of your body.
Alt text: A pregnant woman peacefully sleeps on her left side in bed, supported by a pillow between her knees, illustrating a comfortable sleep position during pregnancy.
This potential compression of major blood vessels has led to concerns about reduced blood flow to the uterus and placenta, which are vital for fetal health. Previous studies, though often small and relying on women’s recall after adverse events, had suggested links between sleeping on the back or right side and higher risks of stillbirth, restricted fetal growth, and preeclampsia – a serious high blood pressure condition in pregnancy.
Reassuring News: Research on Sleep Position Up to 30 Weeks
However, a significant study funded by the National Institutes of Health (Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)) provides a different perspective, at least for the earlier stages of pregnancy. This robust research, published in Obstetrics & Gynecology, investigated the sleep positions of over 8,700 pregnant women and their pregnancy outcomes.
Researchers from the University of Utah School of Medicine, led by Dr. Robert M. Silver, analyzed data from the Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-Be (nuMoM2b). This study followed first-time mothers and collected detailed information about their sleep habits at two points in pregnancy: between 6 and 13 weeks and again between 22 and 29 weeks. Women reported their typical sleep positions when going to bed and waking up, categorizing them as mostly left side, mostly right side, both sides equally, mostly back, mostly front, or other positions.
The findings were reassuring. The study revealed that sleeping on the right side or back, up to 30 weeks of pregnancy, did not increase the risk of stillbirth, small for gestational age babies, or pregnancy-related high blood pressure disorders. In fact, adverse pregnancy outcomes were no more common in women who predominantly slept on their right side or back compared to those who favored their left side or any other position.
To further validate these findings, the researchers conducted a smaller, more objective analysis. They looked at a subgroup of over 400 women who used devices to monitor their sleep positions. Even in this group, women who spent more than 50% of their sleep time on their back did not have a higher risk of adverse outcomes than those who spent less time on their backs. This helps to address concerns about recall bias in studies relying solely on self-reported sleep positions.
Alt text: A graph illustrating the relationship between maternal sleep positions (left side, right side, back, other) and the percentage of adverse pregnancy outcomes in a large NIH-funded study, showing no significant increase in risk for right-side or back sleepers up to 30 weeks.
What Does This Mean for You?
This research offers significant reassurance to pregnant women. If you find yourself more comfortable sleeping on your right side, or if you wake up on your back, especially during your early and mid-pregnancy (up to 30 weeks), this study suggests there is likely no cause for alarm.
Key Takeaways:
- Early and Mid-Pregnancy Comfort: Sleeping on your right side or back during early and mid-pregnancy (before 30 weeks) does not appear to increase the risk of major pregnancy complications like stillbirth, fetal growth restriction, or preeclampsia.
- Listen to Your Body: Comfort is crucial for sleep, especially when pregnant. If you naturally find yourself on your right side and are in your first or second trimester, you can likely relax and prioritize getting restful sleep.
- Not a Free Pass for Late Pregnancy: It is important to note that this study specifically looked at sleep positions up to 30 weeks of gestation. The researchers themselves acknowledge that this study does not provide information about sleep positions in late pregnancy (after 30 weeks). Therefore, the advice to favor left-side sleeping, especially in the third trimester, may still hold.
Important Considerations and Further Research
While this study is reassuring, it’s essential to remember:
- Late Pregnancy: The study’s findings are limited to pregnancies up to 30 weeks. The potential risks associated with back or right-side sleeping in the late third trimester may still exist. Further research is needed to investigate sleep positions in later pregnancy.
- Individual Advice: Always consult with your healthcare provider for personalized advice regarding sleep positions during your pregnancy. If you have specific risk factors or concerns, your doctor can provide guidance tailored to your individual situation.
- Comfort and Sleep Quality: Regardless of position, prioritizing overall sleep quality during pregnancy is vital. If you are comfortable and sleeping well on your right side in early or mid-pregnancy, and your doctor has no concerns, then focus on getting restful sleep.
In conclusion, for many pregnant women in their first and second trimesters, worrying about occasionally sleeping on their right side can be put to rest. Focus on getting comfortable and prioritizing sleep, while staying informed and consulting with your healthcare provider for personalized advice throughout your pregnancy journey.
Reference:
Silver, RM, et al. Prospective evaluation of maternal sleep position through 30 weeks gestation and adverse pregnancy outcomes. Obstetrics & Gynecology. 2019. DOI: 10.1097/AOG.0000000000003458.
