Why are doctors still prescribing bed rest in pregnancy?

Maternity care providers have traditionally prescribed "bed rest," or
activity restriction, for a host of pregnancy complications (including
preterm contractions, short cervix, multiple gestation, and
preeclampsia) despite evidence that it does not improve maternal or
neonatal outcomes. On the other hand, prolonged activity restriction in
pregnancy increases risk for muscle atrophy, bone loss, thromboembolic
events, and gestational diabetes. Although it did not include this
practice in its Choosing Wisely "Five Things Physicians and Patients Should Question" list, the Society of Maternal and Fetal Medicine (SMFM) recently published a strongly worded position paper recommending against activity restriction in pregnancy for any reason.


This isn't the first time reviewers have examined the evidence for activity restriction and found it lacking; a 2013 summary
of several Cochrane reviews of therapeutic bed rest in pregnancy also
found such poor data to support the practice that the authors concluded
its use should be considered unethical outside of the context of a
randomized controlled trial.


The message isn't getting through to physicians or patients, though. A 2009 survey
of SMFM members found that 71 percent would recommend bed rest to
patients with arrested preterm labor, and 87 percent would advise bed
rest for patients with preterm premature rupture of membranes at 26
weeks gestation, even though most of them did not believe it would make
make any difference in the outcome (the most common answers were
"minimal benefit" and "minimal risk"). Unfortunately, the risk may be
more than minimal. Not only does activity restriction expose pregnant
women to harm, a secondary analysis of a randomized trial of preterm birth prevention found that nulliparous women with short cervices whose activity was restricted were actually more likely to deliver before 37 weeks' gestation than those who were not.


Similarly, a search of the terms "bed rest" on popular pregnancy websites Babyzone and Pregnancy.org yielded
the following statements that fly in the face of evidence: "Changing
the force of gravity usually helps minimize preterm labor." "It [bed
rest] helps keep blood pressure stable and low." "In most cases, bed
rest is used to help the body have the best chance to normalize." A
handout on WebMD provided a more balanced assessment:

Bed rest has been a way of treating pregnancy complications for
more than a hundred years. But there's a problem. While bed rest is a
common treatment, there's no proof that it helps. It doesn't seem to
protect your health or your baby's. In fact, bed rest has risks itself.
Doctors still prescribe it, but more because of tradition than good
evidence that it works.


The handout went on to advise patients to question their physicians
closely or get a second opinion if bed rest is recommended. That's
sensible advice. Doctors who are reluctant to abandon this useless and
potentially harmful maternity practice should consult the SMFM paper or the American Family Physician By Topic collections on Prenatal Care and Labor, Delivery, and Postpartum Issues, where no articles recommend activity restriction for pregnancy complications.