Not enough evidence to say if rest is helpful in preventing pre-eclampsia and its complications for women with normal blood pressure during pregnancy.
Pre-eclampsia is a serious complication of pregnancy occurring in about 2% to 8% of women. It is identified by increased blood pressure and protein in the urine, but women often suffer no symptoms initially. It can, through constriction of the blood vessels in the placenta, interfere with food and oxygen passing to the baby, thus inhibiting the baby's growth and causing the baby to be born too soon. Women can be affected through problems in their kidneys, liver, brain, and clotting system. Rest has been proposed as being beneficial for women at increased risk of pre-eclampsia, including those with normal blood pressure. There are also possible adverse effects such as the potential for increasing the risk of blood clots in the legs, and the impact considerable periods of rest on women's lives and that of their families. The review of trials found two small studies, of not very good quality, and there were insufficient data to say what the potential benefits and harms might be. Further studies are needed, and in the meantime women will be guided by their own beliefs and reasoning, as well as those of their caregivers.
Daily rest, with or without nutrient supplementation, may reduce the risk of pre-eclampsia for women with normal blood pressure, although the reported effect may reflect bias and/or random error rather than a true effect. There is no information about outcomes such as perinatal mortality and morbidity, maternal morbidity, women's views, adverse effects, and costs. Current evidence is insufficient to support recommending rest or reduced activity to women for preventing pre-eclampsia and its complications. Whether women rest during pregnancy should therefore be a matter of personal choice.
Women at risk of pre-eclampsia or gestational hypertension are sometimes advised to rest. Whether this, overall, does more good than harm is unclear.
To assess the effects of rest or advice to reduce physical activity during pregnancy for preventing pre-eclampsia and its complications in women with normal blood pressure.
We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (January 2010).
Studies were included if they were randomised trials evaluating the effects of rest or advise to reduce physical activity for preventing pre-eclampsia and its complications in women with normal blood pressure.
Two review authors independently selected trials for inclusion and extracted data. Data were double checked for accuracy.
Two small trials (106 women) of uncertain quality were included. Both recruited women with a singleton pregnancy at moderate risk of pre-eclampsia from 28 to 32 weeks' gestation. There was a statistically significant reduction in the relative risk of pre-eclampsia with four to six hours rest per day (one trial, 32 women; relative risk (RR) 0.05, 95% confidence interval (CI) 0.00 to 0.83), but not of gestational hypertension (RR 0.25, 95% CI 0.03 to 2.00), compared to normal activity. Rest of 30 minutes per day plus nutritional supplementation was associated with a reduction in the risk of pre-eclampsia (one trial, 74 women; RR 0.13, 95% CI 0.03 to 0.51) and also of gestational hypertension (RR 0.15, 95% CI 0.04 to 0.63). The effect on caesarean section was unclear (RR 0.82, 95% CI 0.48 to 1.41). No other outcomes were reported.