Fetal test brings jump in caesareans but little benefit
Last month, my wife, Elizabeth, was admitted to the hospital for the birth of our second child. On the labor and delivery floor, a nurse attached a microphone to Elizabeth's belly. Called electronic fetal monitoring, or EFM, the device made a reassuring ''beep" each time our baby's heart beat in the womb, and traced the rate on a roll of paper. As we waited, the cadence eased our minds.
But, while EFM is used in roughly three-quarters of all American deliveries today, it's a fascinating example of how unproven, potentially harmful technologies become routine practice.
One of medicine's enduring strategies is prevention: You try to catch a problem early and deal with it. For example, consider screening mammograms to prevent breast cancer and PSA screening for prostate cancer. In a similar manner, EFM was supposed to prevent brain damage in babies.
The theory behind EFM is simple: If the baby's heart rate appears abnormal, the baby may be in jeopardy in the womb. (Obstetricians call it a ''nonreasssuring fetal heart tracing.") The baby's brain may become starved for oxygen. Thus, the woman may undergo an urgent caesarean section to prevent any sudden brain damage to the baby.
When it was introduced more than three decades ago, EFM was expected by some experts to reduce rates of cerebral palsy -- that is, brain damage -- by 50 percent in children. The price was going to be more caesarean sections. The widespread adoption of EFM coincided with a fivefold increase in caesarean deliveries. Today, about 20 percent of American pregnancies end in a C-section.
Though childbirth -- both natural and by caesarean -- is generally safe for women (fewer than one in 10,000 die from complications), mothers getting caesareans have a 10 percent chance of surgical infection, a higher risk of uterus rupture in subsequent pregnancies, a higher risk of placental complications in the future, and possibly a higher risk of postpartum depression, compared to women with vaginal deliveries. When a caesarean is done in an emergency, for example, when EFM suggests a sudden problem, a woman's risk of complications jumps.
According to a 2003 report of the prestigious Cochrane Collaboration, a multinational group of experts who review medical practices, simply putting an EFM device -- and tracking the baby's heartbeat -- on a laboring woman increases her risk of having a caesarean section by 40 percent, and ups the risk of episiotomy (cutting the vagina to ease passage) by 20 percent.
Many mothers accept these risks, since they selflessly would risk their well-being for their baby. For many children, cerebral palsy is a devastating, lifelong condition.
The trouble is, EFM has never been proven beneficial. Over the last 30 years, EFM's impact on cerebral palsy rates has been exactly zero. It's simply not a reliable indicator of sudden problems in the baby's oxygen level.
Even if only one in 20 caesarean sections for ''fetal distress" (as measured by EFM) prevented cerebral palsy, disability rates should have fallen sixteenfold, according to a 2003 article in the American Journal of Obstetrics and Gynecology. More conservatively, if only one in 200 such caesareans prevented brain damage, cerebral palsy should have fallen 10 percent. The authors write, ''A test leading to an unnecessary major abdominal surgery in more than 99.5 percent of cases should be regarded by the medical community as absurd at best."
In their comprehensive review of published research, the Cochrane Collaboration in 2003 found no protective effect of EFM for preventing cerebral palsy, neonatal death, or admission to a newborn intensive care unit. In 1990, investigators from the University of Washington reported in the New England Journal of Medicine that EFM actually correlated with a twofold increased risk of cerebral palsy in premature babies -- though nobody has explained the link.
The truth is that cerebral palsy is essentially unpreventable today. Why, then, do obstetricians still use EFM and perform so many unnecessary caesarean sections?
Part of the answer involves the specter of malpractice. Doctors don't use EFM to avoid medical risk -- but to avoid legal liability. Despite the overwhelming evidence that no technology can stop cerebral palsy, obstetricians are sued mercilessly and held responsible for a child's disability if they don't treat supposed ''fetal distress" detected by EFM.
On a fundamental level, many screening tests have flaws, including unexpected side effects, and understanding the potential risks requires great sophistication. Doctors often assume their patients aren't savvy enough to make those choices -- and may decide on a patient's behalf without discussing the possible trade-offs.
For example, many doctors routinely perform mammograms once a woman turns 40 without telling her that after a decade of yearly tests, she has a 56 percent chance of a false cancer scare, and a 20 percent chance of undergoing an unnecessary biopsy. But mammograms prevent death from breast cancer in just two in 1,000 of these women -- so some patients, given the choice, might find these risks unacceptable.
How should expectant mothers decide whether EFM is right for them? Currently, the American College of Obstetricians and Gynecologists ''leaves the decision to the woman and her clinician," though most doctors don't explain that EFM is optional. Some studies have shown that simply listening to the baby's heartbeat occasionally with a stethoscope provides reassurance without the risk of an urgent C-section. Like many women, my wife was never told she had a choice, but thankfully, EFM didn't trigger an emergency delivery.
Doctors need to educate mothers better. At Dartmouth Medical Center, for example, researchers had some patients who were considering back surgery watch a video about the operation's risks and benefits. Presumably better informed because of the video, the patients had 30 percent fewer surgeries. That doesn't mean that surgery was totally unnecessary -- but that education empowers people to make personalized choices based on their own risk tolerance.
Similar innovative strategies are urgently needed to help patients make complex decisions. Otherwise, many mothers may choose an ounce of prevention -- without realizing that it can sometimes cause a pound of hurt.
Dr. Darshak Sanghavi is a clinical fellow at Children's Hospital and Harvard Medical School. His e-mail address is firstname.lastname@example.org.