Both the quantity and quality of sleep are obviously important during pregnancy — you are after all sleeping for two and not just one — but the way you sleep is also vital.
Sowmya, a mother to a five-month-old girl in Bengaluru, had a greater volume of amniotic fluid than usual during her pregnancy. “I wanted to instinctively shift to a position I was used to, or in which I was more comfortable,” she says. “But in the third trimester, I couldn’t turn abruptly. When I wanted to move or turn, I woke up each time. I had to sit up, turn and then go back to sleep.”
In the first trimester, the stomach has not grown large enough to interfere with sleep, so sleeping in any position — lying on the back, on either side, or on the stomach — is fine. As the belly grows bigger in the second trimester, sleeping may start becoming uncomfortable. At this stage, it is best to avoid sleeping on the back or on the front.
“There is an important artery behind the uterus – the inferior vena cava, which supplies blood to the heart,” says Dr Rama Shankarnarayan, gynaecologist and IVF specialist in Bengaluru. “In the second and third semesters, the uterus grows bigger and presses down on the inferior vena cava, slightly reducing the blood supply. The liver is a big organ, so when lying on the back or on the right, it gets pressed on, impairing the functioning of liver and bile secretion. While lying on the back, the uterus applies pressure on the kidneys.”
How to sleep during pregnancy?
“As my belly grew, it was difficult to sleep comfortably. Walking around was challenging, so I spent a lot of time lying on my back,” says Madhuri, mother to a seven-month-old boy in Bengaluru.
Pregnant women spend a lot of time sleeping in the supine position (on their back). One of the reasons for this is that as they gain weight and the size of their abdomen increases, it is no longer convenient to move or turn while lying down. However, research shows that lying on the back may affect the mother and the fetus negatively.
Compared to the lateral (on the side) position, lying on the back causes a higher number of breathing problems, leading to poor quality of sleep. The symptoms are worse in women who have obstructive sleep apnoea, a condition where the upper airway (muscles at the back of the throat) relaxes several times while sleeping, leading to sudden starts and stops while breathing.
Because of the size of the stomach, this can also cause backache and pressure the vena cava, the principal vein in the body. This restricts blood flow and causes dizziness.
The mother’s body pumps lesser blood in the supine position and her oxygen saturation (amount of oxygen in her red blood cells) decreases. Lying on the back also reduces the flow of blood to the legs and increases the heart rate of the mother and the fetus. Sleeping in this position for long periods, especially during the third trimester, affects fetal development.
Best sleep positions during pregnancy
Sleeping on the side has been shown to lead to a marked improvement in maternal oxygen saturation. It improves blood flow to the heart, kidneys and uterus. More oxygen and other nutrients are also delivered to the fetus.
Madhuri was anxious about maintaining the correct sleeping positions during pregnancy. “In the third trimester I slept on my left, following my doctor’s advice,” she says. “But I used to panic, feeling like I was putting too much pressure on the baby. I slept on my back sometimes, but I read that it was bad for the baby, so I consciously stopped.”
It is standard practice to turn a pregnant woman on her side for procedures like ultrasound and abdominal palpation. In situations of fetal distress, a condition where the oxygen levels in the fetus are low, the woman in labour is shifted to the side to improve blood circulation.
“My patients get so scared that they might roll off on the wrong side when they are asleep,” says Dr Shankarnarayan. “They become so conscious about sleeping on the left side that the stress disrupts their sleep. Sleeping on the left is preferred, but there is nothing wrong with moving to another position while sleeping. Sleeping well is the most important thing.”
There is no harm in sleeping on the stomach in the first few months, but as the belly grows, it may affect the spine and organs adversely, so it isn’t recommended.
Best sleeping position for a pregnant woman
Modifying sleep positions, therefore, can lead to better outcomes for the mother and the fetus.
Sleeping on the left side with the legs curled is usually the most comfortable during pregnancy sleeping positions. Making a habit of sleeping on the side from the first trimester will help at a later stage; continuing this through the second trimester will make sleeping on the left comfortable when the belly has grown big enough to disrupt sleep and cause discomfort.
Using a pillow under the belly or between the legs is another option. Keeping a few pillows at the lower back may also relieve some pressure. Supporting the body with pillows on the side may give relief to sore hips.