The Wall Street Journal published a piece on the ubermoms of Brooklyn who want to homebirth.  As a feature story, the piece made a number of interesting observations specific to New York, such as how birth noises might impact neighbors in tightly packed apartment buildings, potential issues with a hospital transfer for a laboring woman in a fifth-floor walk-up, and the desire for homebirth in the Orthodox Jewish community because Cesareans pose a risk to having large families.

Whenever homebirth is mentioned, people go berserk about risk.  The comments in the WSJ piece are full of lines like, “Please do not have you children at home… If someothing (sic) happens, you will live with your guilt for the rest of your life” ; and “People are fools.”  Others point out that women want to homebirth because the Cesarean rate in most New York City hospitals is around 40% and it is very difficult to have an intervention free labor and birth in these hospitals even if the there are no complications.

Two ways of considering risk are looking at relative risk and absolute risk.

Relative risk considers the risk of one choice vs. another.  For instance, your risk of choking to death on a piece of meat or a raw carrot chunk is much higher than your chance of choking on a spoonful of pudding washed down with a swig of Coke.

Absolute risk considers how likely it is that each event will actually happen.  Continuing with the example above, you might consider your risk of developing tooth decay vs. death by choking.  In considering such choices, you might ask, what is my  risk of dying by choking to death vs. my  risk of tooth decay?  You might decide that, though death is a very serious risk, the very tiny  risk of death is less serious that the much higher risk of tooth decay.

We make decisions with poor relative risk profiles all the time because the absolute risks are small.  Sometimes this is done for convenience; for instance, we often ride in cars rather than walking.  Sometimes we do it for pleasure; we might choose to go mountain climbing rather than staying at a nature center watching videos of mountain climbing.  And studies show that we often assess risk poorly, living in fear of rare events like school shootings and terrorist attacks while blithely driving or taking showers without a skidmat.

The article points out that relative risk statistics indicate that the chance of infant death is about three times higher in a home birth than in a hospital birth (this statistic, based on the infamous Wax study, has been widely disputed, but for the sake of argument, we’ll proceed as if it is accurate).  However, the chance of death during a birth is very, very small (statistics on neonatal death consider all deaths by 28 days after birth; infant mortality counts all infants who die in the first year of life–these are different statistics from deaths during birth or in the few minutes afterward).  According to the Wax study, among babies without birth defects, the chance of death at a homebirth was .15%, or 1.5 per 1000 births.  As statistician Marian F. MacDorman says in the article, “the absolute risks of home birth are very low, no matter how you slice it.”

Weigh that against the chance of a cesarean at a hospital birth (approximately 400 per 1000 according to the article; the World Health Organization says 150/1000 is a “threshold not to be exceeded”). And according to the article, the chance of unwanted birth interventions in the hospital is close to 100%, meaning almost 1000/1000.  These interventions can include everything from administration of Pitocin to continuous electronic fetal monitoring, to artificial rupture of membranes, all of which have risks of their own, especially when used without indication.

With honest information, a woman can decide whether the relative risk of death in homebirth vs hospital birth (if the statistic is even accurate) is worth the absolute risk of major abdominal surgery or of unnecessary intervention that can cause pain, infection, loss of autonomy, neonatal complications, or even maternal or infant death.  It is completely legitimate for a woman to make a decision based on her own assessment of the risks, and that includes her right to assume the risks of either home or hospital birth, as well as consideration of risk to herself as well as her baby.

Wall Street Journal article: http://online.wsj.com/article/SB10001424127887323639704579016902834439742.html

Wax study abstract (look at the results as well as the conclusion): http://www.ajog.org/article/S0002-9378(10)00671-X/abstract

Complete text of the Wax study: http://dhmh.md.gov/midwives/Documents/Wax-etal.pdf

Overview of critiques of Wax study: http://www.scienceandsensibility.org/?p=2551

World Health Handbook on Monitoring Obstetric Care (see p. 25):  http://www.who.int/reproductivehealth/publications/monitoring/9789241547734/en/index.html

Book about Americans’ poor risk assessment: http://www.amazon.com/Culture-Fear-Americans-Minorities-Microbes/dp/0465003362

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