Journal Issue: Low Birth Weight Volume 5 Number 1 Spring 1995
Bed Rest to Prolong Pregnancy in Twin Pregnancies
Bed rest is a common recommendation for women whose pregnancies are complicated by one or more of a wide variety of conditions, such as multiple pregnancy, preeclampsia (pregnancy-induced high blood pressure), spontaneous abortion, fetal growth retardation, and threatened preterm delivery. Despite little evidence of its effectiveness in preventing adverse outcomes, bed rest is used in nearly 20% of all pregnancies.32 Most notably, hospitalization for bed rest in twin pregnancies has been advised. Twin pregnancies account for approximately 1% of all pregnancies, but they account for approximately 10% of perinatal deaths.33 Compared with singletons, the death rate among twins is considerably higher for every major cause of death.33 Thus, in the belief that prolongation of pregnancy or some other improved outcome may result, bed rest, either in hospital or at home, has been commonly recommended by many clinicians, even in the absence of preterm labor. Because hospitalization is a costly and socially disruptive procedure, a benefit in fetal or maternal outcome should be demonstrated before it is widely applied.34,35 Because scientific evidence on bed rest and singleton pregnancies is absent and because most of the research on bed rest and hospitalization has been conducted on women with twin pregnancies, an evaluation of those studies on the effectiveness of bed rest in improving twin pregnancy outcomes will be discussed.
Some small early studies appeared to show a decreased frequency of preterm birth and perinatal mortality with bed rest in the hospital in twin pregnancies.36-38 But none of the recent randomized controlled trials of bed rest in the hospital in twin pregnancies during the third trimester of pregnancy have shown a prolongation of pregnancy.39-41 However, results of the three trials suggest that there may be a decreased risk of developing hypertension and a reduced incidence of low birth weight from routine hospitalization. Initial studies of hospitalization in the second trimester of pregnancy (28 to 29 weeks of gestation) found no increase in the length of pregnancy.42,43
In summary, it is not logical at present to prescribe routine bed rest or hospital admission for twin pregnancies. Most of the studies have excluded women with complications such as bleeding during pregnancy, pregnancy-induced hypertension, polyhydramnios (increased amounts of amniotic fluid), and previous cervical cerclage or cesarean delivery. Thus, randomized controlled trials of bed rest in the hospital for complicated twin pregnancy or higher multiple pregnancy are needed before this treatment can be widely recommended.
In spite of the apparent simplicity of this treatment, bed rest has the potential to extract a large economic toll on families. Obviously, bed rest in the hospital is costly, but in most instances (75% of the time), physicians prescribe bed rest at home, which can also be extremely disruptive to the family. Prolonged bed rest may result in the loss of substantial income and employment, and may also result in serious side effects.32 In the absence of proof of the effectiveness of bed rest, its use should be curtailed sharply, and randomized trials should be conducted to see if bed rest at home or in the hospital actually does prevent the wide array of conditions for which it is currently used.