As many mothers can attest, soon after the bliss of discovering you’re pregnant comes a tidal wave of questions and concerns. It’s hard to not feel buried under them while you sort through what’s real or hearsay, and what’s appropriate for your body and mind or not.
Often, without context, pregnant mamas are cautioned to not move their bodies in a particular way, leading to misunderstanding and fear. It also can be difficult to find up-to-date guidance as new research emerges. This stifles pregnant mamas from moving their bodies and reaping the benefits of regular movement – for themselves and their growing babies. I love giving mothers back their power with knowledge of what their bodies are capable of during pregnancy and how they can confidently practice the movement they love.
Avoiding lying on your back (also known as supine position) is one of those concerns that can limit movement. Doctors typically advise pregnant mothers to not lie on their backs during later pregnancy (second and third trimesters) because of the concern that the weight of the growing uterus and baby may compress their inferior vena cava, the largest vein in the body. There’s good reason for this warning, and it’s called Supine Hypotensive Syndrome. However, for many women, there also are ways to avoid this concern and safely exercise in supine positions.
Supine Hypotensive Syndrome
For anyone who’s experienced a compressed vena cava, you know very clearly what it feels like: light-headedness, nausea, sweating, increased heart rate and reduced blood pressure. Symptoms of Supine Hypotensive Syndrome usually occur within 3-10 minutes of lying down. It has been shown to occur in up to 15% of pregnant mothers when they’re at term. Thankfully, there’s an immediate remedy: simply rolling over to your left side, allowing the blood to flow fluidly again.
Studies on this syndrome have shown that lying on your back for long periods during late pregnancy can contribute to reduced uterine blood flow, potentially leading to fetal growth restriction and increased risk of late term stillbirth. This is why medical experts say sleeping on your side is safest because it avoids prolonged time on your back.
However, these studies also have shown that by moving in and out of supine position, there is no effect on the motility of blood through the vena cava. As it turns out, the nuisance of having to urinate so frequently during pregnancy, particularly while sleeping, partly guards against this syndrome!
Lying on Your Back During Exercise
With regard to exercise, it’s a good idea to not lie on your back for extended periods of time, but that’s rarely necessary. And if while lying on your back you begin to feel lightheaded, you can change positions and experience immediate relief. Simply adding a pillow to elevate your shoulders can prevent compression. Similarly, lifting your hips in bridge sequences allows the blood to continue moving smoothly.
Exercising on your back opens up a more versatile set of movements to practice – most often to strengthen your deep core muscles, and it’s a wonderful position to utilize if you’re someone who can tolerate it.
The most important indicator is your own body. If you sense unusual or uncomfortable symptoms while lying on your back, even for short durations, simply move to your left side. Try modifying the exercise with some elevation under your shoulders or change the movement entirely. There are many effective and challenging core exercises that do not require you to be on your back!
Please reach out to hello@navewell.com if you’d like guidance exploring safe and effective exercise during pregnancy, before or afterward.
References
Anderson, NH, Gordon, A., Li, M., Cronin, RS, Thompson, JMD, Raynes-Greenow, C.H., Heazell, AEP., Stacey, T., Culling, VM, Wilson, J, Askie, LM, Mitchell, EA, McCowan, LME (2019). Association of Supine Going-to-Sleep Position in Late Pregnancy With Reduced Birth Weight: A Secondary Analysis of an Individual Participant Data Meta-analysis. JAMA Network Open, 2(10).
Heazell A, Li M, Budd J, Thompson J, Stacey T, Cronin RS, Martin B, Roberts D, Mitchell EA, McCowan L. Association between maternal sleep practices and late stillbirth - findings from a stillbirth case-control study. BJOG. 2018 Jan;125(2):254-262.
McCowan LME, Thompson JMD, Cronin RS, Li M, Stacey T, Stone PR, Lawton BA, Ekeroma AJ, Mitchell EA. Going to sleep in the supine position is a modifiable risk factor for late pregnancy stillbirth; Findings from the New Zealand multicentre stillbirth case-control study. PLoS One. 2017 Jun 13
Mottola, MF, Nagpal, TS, Bgeginski, R, Davenport, MH, Poitras, VJ, Gray, CE, Davies, GA, Adamo, KB, Slater, LG, Barrowman, N, Barakat, R, Ruchat, S (2019). Is supine exercise associated with adverse maternal and fetal outcomes? A systematic review. British Journal of Sports Medicine 53:82-89.
Sherman C, Gauthier M, David M. Supine Hypotensive Syndrome of Pregnancy. In: Freeman BS, Berger JS. eds. Anesthesiology Core Review: Part Two Advanced Exam. McGraw Hill; 2016.
Silver, RM, et al. Prospective evaluation of maternal sleep position through 30 weeks gestation and adverse pregnancy outcomes. Obstetrics & Gynecology. 2019.