Imagine lying in bed for weeks at a time, looking at the ceiling, or Netflix or a book. If you stand up, something really bad might happen. So, you go to the bathroom only when absolutely necessary, and if you're doing it right, you eat or drink only what people bring you. Maybe you have a dog that needs to be exercised, or a job to go to or a toddler to chase around — that doesn't matter, though. What matters is that you stay in bed — or on the couch, if you want — and wait until your doctor says you can get up.
That might sound kind of nice to you, or it might sound hellish, but the reality is, about 20 percent of women go through this for some part of their pregnancy. Bed rest, which can range from supervised time in a hospital bed to limiting normal daily activities and a lot of sitting around, is prescribed for all kinds of pregnancy complications, from gestational diabetes to poor fetal development to an "incompetent cervix." It's a pretty old idea, but it became a mainstay of western obstetrics in the 19th century, when any sign of complications would land a lady alone in bed, in the dark, sometimes even with earplugs — basically a sensory deprivation chamber. It looks different these days — you can have conversations and listen to music if you want, but being pregnant and flat on your back is still a complete drag.
The problem is, scientific evidence to support putting women to bed when pregnancy gets tricky is pretty thin. In fact, a 2013 review of recent scientific research found that not only does bed rest offer no medical benefit, there's also quite a bit of evidence that it's harmful.
"There is a longstanding myth that pregnant women should be put to bed, they shouldn't exert themselves, they should be in dark rooms, etc.," says Dr. Anne Drapkin Lyerly, an obstetrician and professor of bioethics at the University of North Carolina at Chapel Hill School of Medicine who co-authored the review. "The thinking has evolved that there might be physiologic benefits to that but there's nothing to prove it, and in fact, there are some studies that show that the outcome you're trying to avoid — say, preterm birth — is more common in women who get put to bed than in women who don't."
The biggest medical concern for women put to bed seems to be blood clots:
"We know that both immobilization and pregnancy result in higher risk of blood clots," says Lyerly. "So if you're pregnant and immobilized, you have a much higher risk of developing blood clots in your legs and pelvis, which can be dangerous because there's a chance one will break off and travel up to the lungs, causing pulmonary embolism, which can be life threatening."
But that's not all. Imagine the other things that could happen when you don't move for, say, 10 weeks at a time: When you don't put weight on your body, your bones demineralize and become weaker, leading to conditions like osteoporosis. There is also the risk of muscle atrophy, which can be problematic for a woman's overall health, but also for her lifestyle when she has a job that involves a lot of moving around, or an active toddler at home or even the need to buy a bag of dog food at the grocery store.
"There are also psychological risks like depression and anxiety, as well as socioeconomic risks," says Lyerly. "So many women work, putting them to bed might mean they could lose their jobs, lose income, need to hire childcare — their partners might need to scale back on work. There are some significant socioeconomic consequences for people."
And then there's the problem that comes when a doctor prescribes bed rest — a practice that's been proven to be ineffective — which creates the impression for the woman that the success of her pregnancy hinges on her not moving at all. What if she goes to the bathroom or takes a shower or walks to the kitchen for a snack? If she loses her baby, she's likely to blame herself.
"That can be a lifetime of guilt for someone," say Lyerly. "It makes the physician feel like they're doing something — they're acting as if they have something to offer a patient, when in fact they're harming them by prescribing it."
So, since the evidence seems pretty clear that strict bed rest is harmful and not beneficial, why do doctors prescribe it so often? According to one 2008 study, it's a question that puzzles even the experts:
"We cannot explain why obstetricians recommended an intervention they believed was not beneficial," wrote the authors. "This is unfortunate because bed rest is not a benign intervention and can have a significant social and economic burden on the patient and her family."