As soon as a woman becomes pregnant, she is inundated with all forms of information from well-meaning people, some of whom feel they are experts on the subject because they have had a pregnancy themselves. Unfortunately, there are many myths and misconceptions that have been perpetuated from generation to generation.
- “If you sleep on your back, the baby will not be able to breath”
- “You cannot sleep on your back from the time you conceive until the time the baby is born.”
- “Doctor, I woke up during the night and found myself flat on my back. Is my baby okay?”
“You should not lie directly on your side or on your belly as it will cause deformities of the baby’s limbs.”
There is a scientific basis behind the advice we give women about sleeping positions in pregnancy, but this sometimes gets lost in translation when passed on by others. Below is my attempt to give you the facts.
Beyond 24 weeks the uterus is heavy enough to block off the veins returning blood from the lower half of the body.
If you lie flat on your back, the vena cava (major vein) is compressed and blood returning to the heart is decreased. As a result, the blood pumped out by the heart is also decreased, which means, there is less blood getting to the placenta. Babies can cope with this for a short period of time, but if you lie flat for long periods of time, the baby will become distressed and suffer from low oxygen levels. It does not affect baby’s breathing as unborn babies DO NOT BREATH.
To combat this you can lie flat as long as you are tilted about 15 degrees to either side. In a semi-reclined position (i.e. 30 degree head up tilt) you only need a 10 degree side tilt. The best way to sleep in a semi-reclined position is to put a bean bag at the top half of your bed and throw a sheet over it. The bean bag will then hold its form. Pillows can be used but they tend to move in the night and you find yourself lying flat on your back. If you wake up flat on your back, don’t panic. Your baby will tell you it is okay when it moves. Babies have quiet periods for up to 45 minutes so you should feel a movement within 60 minutes if you sit quietly and wait.
Lying directly on your side is perfectly okay in pregnancy. Your baby has fluid around it that will cushion it and protect it. Lying on your belly is also okay for the same reasons, but beyond the first trimester, this becomes uncomfortable and women choose to avoid this position.