Results show that the mean systolic blood pressure in the third trimester was 114 mm Hg in women with a normal self-reported nightly sleep duration of nine hours in early pregnancy, 118.05 mm Hg in women who reported sleeping six hours or less per night, and 118.90 mm Hg in women with a nightly sleep duration of 10 hours or more in early pregnancy. After adjustments for potential confounders such as age, race and pre-pregnancy body mass index, mean systolic blood pressure was 3.72 mm Hg higher in short sleepers and 4.21 mm Hg higher in long sleepers. Similar results also were found for diastolic blood pressure.
"Both short and long sleep duration in early pregnancy were associated with increased mean third trimester systolic and diastolic blood pressure values," said lead author Doctor Michelle A. Williams.
The study also found an association between sleep duration and preeclampsia, a condition that involves pregnancy-induced hypertension along with excess protein in the urine. The risk of developing preeclampsia was almost 10 times higher in very short sleepers who had a nightly sleep duration of less than five hours during early pregnancy. Overall, about 6.3 percent of participants were diagnosed with either preeclampsia or pregnancy-induced hypertension without proteinuria.
"If our results are confirmed by other studies, the findings may motivate increased efforts aimed at exploring lifestyle approaches, particularly improved sleep habits, to lower preeclampsia risk," said Williams.
The study involved 1,272 healthy, pregnant women who completed a structured interview at 14 weeks gestation, on average. Sleep duration in early pregnancy was evaluated by the question, "Since becoming pregnant, how many hours per night do you sleep?" Only about 20.5 percent of women reported a sleep duration of nine hours per night, which was used as the "normal" reference category because prior research indicates that pregnant women tend to have longer sleep duration patterns. About 55.2 percent of women reported sleeping seven to eight hours per night, 13.7 percent slept six hours or less and about 10.6 percent slept 10 hours or more.
MEDICA.de; Source: American Academy of Sleep Medicine