Why Pregnant Women Should Sleep On Their Sides

A new study has found that the advice for pregnant women to sleep on their sides has proven to be beneficial to the unborn baby’s well-being.

Researchers from the University of Auckland have discovered that there is a solid evidence that pregnant women sleeping on their sides can help the baby’s well-being as it allows more foetal activity.

The research, published in the Journal of Physiology, found that when a mother slept on her back, her baby was less active, but when she sleeps on her left or right side, the baby’s foetal activity, which is one measure of a baby’s well-being, goes up.

The study was composed of 30 healthy pregnant women, with healthy singleton pregnancies, between 34-38 weeks, and were studied in their home with researchers setting up an infrared video camera to record their spontaneous sleep positions. The heart rate of both women and their bubs were also recorded continuously overnight using an ECG.

The researchers found that women most often fell asleep on their left sides and remained in that position for more than half of the night. However, women did spend a median of one hour and 23 minutes asleep on their backs.

They also noted that many pregnant women go to the loo frequently. “The timing of arising to toilet was spread widely throughout the night,” the researchers said.

As to the unborn baby’s activities, they were most active when their mums were on their sides, and moved the most in the hours between 9 pm and 1am.

So how does foetal activity relate to a baby’s well-being? “Decreased foetal movements are associated with adverse pregnancy outcomes including hypoxia at birth or stillbirth,” the researchers explained.

The researchers also noted that maternal back sleeping in late pregnancy may have an effect on an unhealthy baby. “In the situation where the baby may not be healthy, such as those with poor growth, the baby may not tolerate the effect of maternal back sleeping,” they said.

“Our findings make sense as lying on the back in late pregnancy is associated with physical effects that can compromise the baby’s well-being,” said lead researcher Professor Lesley McCowan. “These include a reduction in the mother’s cardiac output (the amount of blood pumped by the heart per minute), a reduced blood flow to the uterus, and lower oxygen levels in the baby”.

Another University of Auckland study done earlier this year found that women who sleep on their backs during the third trimester are almost four times more likely to experience a stillbirth.

Source: Essentialbaby.com.au