Friday, July 19, 2013

Activity Restriction and Bed Rest in Pregnancy - Insufficient Evidence for Use and Potential Harms

It seems to make sense that "bed rest" during pregnancy, especially one that is threatening preterm labor or other complications, would be helpful. I mean, wouldn't staying in bed, rather than doing her normal activities, be a good thing for a mother and her baby?

The answer is NO. Bed rest actually increases risks for the mother and baby and causes a great emotional and financial toll on many families. Understand that this is only referring to complete activity restriction and strict bed rest, not to say that pregnant women should not rest. You should listen to your body and rest when you need to, always.

The Journal of Obstetrics and Gynecology published 3 articles in its recent June 2013 issue about bed rest and the unethical use of this practice. Let's take a look at the research and put this issue to rest!


Historically, bed rest was intended for orthopedic ailments, but quickly spread to all areas of medicine, without question of its benefit. Sounds familiar...

Overtime, evidence of the adverse effects from bed rest began to accumulate. Negative physical effects were recognized, such as muscle athrophy, bone de-mineralization, cardiovascular de-conditioning with loss of plasma volume, venous thrombosis, and alterations in the endocrine and immune systems. Subsequently, bed rest recommendations began to change for individuals recovering from myocardial infarction, pulmonary infections, and in postoperative recovery. Slowly, the recommendations for prolonged bed rest during or after an uncomplicated pregnancy began to dissipate...

"However, bed rest remains one of the most commonly prescribed treatments to improve reproductive outcomes in complicated pregnancies, despite a lack of evidence that it improves any obstetric or neonatal outcomes."(1) ...and as well see soon, can actually makes some outcomes worse!


McCall and Colleagues (2) published a summary of the literature concerning activity restriction and bed rest from the Cochrane Review. The review demonstrated that there is insufficient evidence to routinely recommend bed rest during pregnancy and due to some of the potential adverse side-effects, bed rest may even be harmful and unethical to prescribe.

Here is what the evidence says for various pregnancy-related conditions:
  • Miscarriage (or spontaneous abortion) - There was no substantial difference in the risk of miscarriage between bed rest and no bed rest for two trials included in the review.
  • Hypertension - One small trial demonstrated a small significant difference in severe hypertension for women who were on bed rest compared to no bed rest, but there were only 218 patients and other randomized controlled trials do not support the routine recommendation of bed rest for hypertension in pregnancy. 
  • Healthy Women (with normal blood pressure) - there is insufficient evidence to support the use of bed rest for the prevention of pregnancy-induced hypertension. Two small trials (with 32 and 74 participants) have been conducted which demonstrated that some bed rest during the day (4-6 hours) decreases risk of preeclampsia, but not gestational hypertension. The authors recommend using caution when interpreting this data because of a small n (participants) and the fact that strict bed rest was not studied in either trial, just some bed rest. They end by saying, "whether women rest during pregnancy should therefore be a matter of personal choice." Rest if you feel like you need to!
  • Preterm birth - current evidence does not support (or refute) the use of bed rest. There was only one trial included in the review (and we'll look at another one below), but the authors conclude that, "Due to the potential adverse effects that bed rest could have on women and their families, and the increased costs for the healthcare system, clinicians should not routinely advise women to rest in bed to prevent preterm birth.
  • Preterm birth - A recent study (3) looked at women with a short cervix (defined as less than 30mm) to determine if bed rest would be appropriate for these women- who are at greater risk of preterm labor. In fact, women placed on activity restriction were 2.37 times more likely to deliver preterm (before 34 weeks of gestation) than women not placed on any activity restrictions. The bed rest recommendation actually appears to have been harmful for these babies.
  • Multiples - there were 7 trials included in this review and bed rest did not reduce the risk of preterm birth or perinatal death. One study demonstrated a small decrease in low-birth weight babies (less than 2,500g), but not in very low-birth-weight neonates (less than 1,500g). Dues to risks of strict bed rest, there is insufficient evidence to routinely recommend it for women carrying multiples. Just remember to rest when YOU feel like you need to!
  • Small for gestational age/suspected impaired fetal growth in singleton pregnancies - there was no difference in birth weight between groups; the evidence does not support bed rest for improved fetal growth.

Try prenatal yoga!
  • Increases the risk of preterm labor in women with a short cervix (less than 30mm) (Odds Ratio: 2.37; CI 95% 1.60-3.53). Meaning that you are 2.37 times more likely to experience a preterm labor if you have a short cervix and are placed on strict activity restriction. 
  • Increases the risk of venous thromboembolism (blood clots) (Relative Risk: 19; CI 95% 5-80). Meaning you are 19 times as likely to develop a blood clot if placed on bed rest than women who remain active.
  • Bone mineralization (bone loss) is increased in women on bed rest to a mean loss of 4.6% compared to ambulatory women (those not put on bed rest) of only 1.5% (bone loss is normal in pregnancy to a degree - which is why your body needs time in between babies to replenish nutrients! read about optimal pregnancy spacing here)
  • Increased muscle atrophy
  • Pulmonary atelectasis (a complete or partial lung collapse)
  • Psychological effects to the mother, father, and other children, including: anxiety, stress, and increased psychological suffering. Increased demands on the father may also lead to fatigue. 


The financial toll of bed rest on families and the economy is astounding, especially considering the routine practice may be contributing to even greater health risks and costs. In 1993 it was estimated that the annual cost of bed rest was as "little" as $1.03 billion and quite possibly as high as $5.7 billion. When this is adjusted for 2013 the cost ranges from $2 billion to $7 billion per year (1). All this cost would be acceptable IF bed rest improved health of mothers and babies... but it doesn't!

In addition, the family will likely suffer the loss of one (or some) of the mother's income and the mother is no longer able to contribute to the household in the many ways she did before - these tasks will fall to her partner and many things will have to be neglected. Other children may experience psychological distress due to their mother's inactivity and the emotional states of their parents. Paid parental leave is very rare and many families cannot afford the loss of any income.


So how big of a problem is this? Approximately 18% of pregnant women in the U.S. each year will be placed on bed rest at some point in their pregnancy. Unfortunately 71% of Maternal-Fetal Medicine Specialists would recommend bed rest for preterm labor and 87% would recommend it for premature rupture of membranes; over half of the specialists reported that they perceived little to no benefit to bed rest. (2)

The continued recommendation of activity restriction and bed rest may be because doctors fear being held liable for complications in pregnancy and birth, so they feel that prescribing something is better than nothing... but in this case, recommending nothing would be better than bed rest!

Walking is great for everyone!

Be sure to ask your doctor why they are recommending bed rest. Are they just recommending you find some more time to relax and rest? Do you just need to decrease your stress inducing activities? It is reasonable to request that a woman slows down to care for herself, her baby and her emotional/physical health.

Or, has your doctor recommended that you completely restrict your activity? Be sure to find out the reasons for the recommendation and determine if you need to seek a second opinion. Remember, there is insufficient evidence to routinely recommend strict bed rest for complications in pregnancy and even some evidence of potential harm. 

Remember the Hippocratic oath, "First, Do No Harm"... well strict bed rest is more harmful than beneficial and it is time we ended its practice!

Be active, healthy, and rest when you need to!
~Wisdom and Birth

Please remember that this is not medical advice, just a summary of current research literature. Talk to your midwife, doctor, or other health provider if you have questions or concerns. 

(1). Biggio JR. Bed rest in pregnancy: time to put the issue to rest. Obstetrics and Gynecology 2013; 121(6): 1158-1160.
(2) McCall CA, Grimes DA, Lyerly DA. "Therapeutic" bed rest in pregnancy: unethical and unsupported by data. Obstetrics and Gynecology 2013; 121: 1305-1308.
(3) Grobman WA, Gilbert SA, Iams JD, Spong CY, Saade G, Mercer BM, et al. Activity restriction among women with a short cervix. Obstetrics and Gynecology 2013; 212: 1181-86.

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