On April 1st, a new study conducted in New Zealand was released showing that sleeping on your side during pregnancy can greatly reduce your risk of having a stillbirth. The international study provided evidence that in performing this seemingly meaningless task, it can more than halve your risk of having a stillborn child, especially during the last 3 months of pregnancy.
With an estimated 2.64 million babies around the world dying before birth, researchers and mothers alike are eager to learn new ways of reducing that number. According to The Conversation, "This mega-study (known as individual participant data meta-analysis) has also confirmed the risk of stillbirth associated with sleeping on the back applies to [ALL] pregnant women in the last trimester of pregnancy".
The question remains as to why sleeping on your back poses such a risk to an unborn baby, with that risk getting more substantial the more you progress through your pregnancy. Through Magnetic Resonance Imaging (MRI), it was shown that when a pregnant woman lays on her back, her womb compresses a very important blood vessel called the inferior vena cava. Applying pressure to this vessel reduces blood flow to the womb by up to 80% which can starve an unborn baby of much-needed oxygen.
In order to reduce this risk, pregnant women are advised to sleep only on their side after the first trimester but especially during the third trimester when the womb is much heavier. The best thing to do is to always fall asleep on your side, even during naps. Many women say that even if they fall asleep on their side, they're often waking up on their back which is okay as long as you flip back onto your side upon realizing. If you find yourself waking up on your back a lot, propping a pillow up behind you may help prevent you from turning over.
According to the New Zealand study, some of the vast numbers of babies who die in utero annually can actually be prevented. The "mega-study has shown that if every pregnant woman went to sleep lying on her side after 28 weeks of pregnancy, approximately 6% of late stillbirths could be prevented. This could save the lives of about 153,000 babies each year worldwide".