Sleep essential for mothers-to-be

London: Newly pregnant women who get less than five hours sleep a night are more likely to suffer from problems in birth, research shows.

They are ten times more at risk from pre-eclampsia, a condition which causes high blood pressure, leading to organ damage and even the death of the unborn baby.

It can also be fatal for the mother who, once diagnosed, is given a Caesarian or drugs to induce the birth prematurely. Mothers-to-be who get five hours sleep or less a night within the first 14 weeks are ten times more at risk, the American researchers found.

During sleep, a person's average blood pressure falls by between 10 and 20 per cent.

This means that those who sleep for fewer hours a night will have a higher-than-average blood pressure over a 24-hour period.

Scientists from Washington University believe that even though this increase in blood pressure is fairly small, it affects the way the heart functions throughout pregnancy.

Hormone levels

They also say that not getting enough sleep changes the levels of the hormones endothelin and vasopressin.

Both widen and restrict the size of the blood vessels throughout the body, which affects the blood pressure.

Oddly, the research also found that both women who sleep a lot and those who do not sleep enough have slightly higher blood pressure later on in pregnancy.

Those who sleep for six hours or less a night, or for more than ten hours, have an average reading 3.5 per cent higher than those who sleep for the recommended nine hours.

Health problems

Although people are encouraged to sleep for an average of seven or eight hours a night, pregnant women are advised to sleep for longer to ensure they do not become exhausted and develop health problems.

The scientists are not sure why sleeping a lot also increases blood pressure, but suspect it may be related to other conditions such as depression and breathing during sleep.