I thought the news coverage of a recent study on planned home births vs hospital births was really interesting. The article, Selected perinatal outcomes associated with planned home births in the United States, appeared in the October issue of AJOG.
I’ll come clean here–I have two kids, and they were both born in hospitals. My goal both times was to minimize intervention, but I never seriously considered a home birth. I know I don’t have a very high pain tolerance, and though I tried to get through labor without meds both times, I wanted to know that they would be an option. In the end, I got an epidural for each birth (and was extremely grateful for it). But the climbing C-section rates, the prison-like environment of the hospital… I understand the appeal of the home birth for many women. So I’ve been following home birth vs hospital birth safety studies with a lot of interest.
I’ll summarize the study’s findings and then review some of the media coverage, which I found a little surprising.
What the researchers did
Basically, the authors looked at two different types of outcomes: (1) neonatal outcomes, such as the 5 minute APGAR score for babies and whether babies had seizures and (2) maternal outcomes, such as operative vaginal delivery (i.e. forceps or vacuum used) and labor induction/augmentation. They analyzed over 2 million singleton births that occurred in 27 states in 2008, roughly 12,000 of which were home births. I think it’s fantastic they were able to look at only singleton births and that they were able to identify planned home births. That way, they aren’t counting emergency situations where women can’t make it to the hospital as “home births,” and riskier multiple births don’t enter the analysis, complicating things. In case you’re interested, here are some other birth types that were excluded from the dataset: breech deliveries, deliveries that were < 37 or > 43 weeks, and births at freestanding birthing centers. In other words, they were trying to focus on relatively low risk births.
Women who plan home births are a unique subset of mothers
The authors found that by virtually any measure, women who plan home births are different than those who do not. They are more likely to have given birth before. They are older. They are way more likely to be white. And married. They are more educated. They initiate prenatal care later. And their babies are born at a later gestational age. Obviously, when you are comparing an outcome in two groups of people that differ in so many ways, epidemiological studies are very, very tough to interpret. The authors tried to control for these differences as best they could by using multivariate models that adjusted for parity, maternal age, race/ethnicity, educational level, marital status, gestational age at delivery, smoking during pregnancy, prenatal visits, and medical conditions such as gestational diabetes and preeclampsia. However, residual confounding is always a problem. Sometimes a big one.
Planned home births are more likely to result in babies with an Apgar score of < 4 and babies who had seizures
Planned home births were roughly twice as likely to result in a baby with an Apgar score of < 4. A score of < 4 is pretty serious stuff–it is a very good indicator of neonatal death. However, the absolute number of such births was small in both home and hospital groups (0.37% for home births, 0.24% for hospital births). And babies from planned home births were roughly three times more likely to have seizures (although again absolute numbers were small: 0.06% vs 0.02%).
Babies born in planned home births are less likely to end up in the NICU
The authors found that babies born in the hospital were roughly five times more likely to end up in the NICU (remember that these are adjusted odds ratios, so gestational age and maternal complications are included in these calculations).
Planned home births are associated with significantly lower levels of intervention
This is probably no surprise to most people. Women who gave birth at home in a planned delivery had about a tenth the odds of operative vaginal delivery, a fifth the odds of labor induction, a third the odds of labor augmentation, and less than half the odds of antibiotic use.
So what’s the take home?
I think any epidemiologist will tell you that studies like this are really, really tough to interpret. There will probably never be a randomized controlled trial of home vs hospital births. And the women who choose home births are different in many ways than women who do not, so residual confounding is always a problem. Plus, we don’t have a way at present to identify women who wanted to give birth at home but ended up in the hospital with complications… so this may actually result in underestimation of the risks associated with planned home birth.
This study had a lot of strengths, though. Relatively large sample size, relatively low-risk births being compared, adjustment for many potential confounders. Given the findings, what’s a pregnant woman to do? How do you weigh the greater (but still very unlikely) odds of neonatal complications with the lower (but much more common) odds of maternal interventions, which carry their own risks? There are some tough tradeoffs here. I was curious how the media would interpret this study.
The media spin: Ignore the mothers
Here’s how different news organizations interpreted the study.
The headline in Science News was Home births more risky than hospital deliveries. The reporter here decided to focus on neonatal outcomes without mentioning the other half of the paper: maternal outcomes. He did point out the low absolute occurrence rate of neonatal problems, though, which is great. I find that often absolute risk isn’t discussed in news articles, and it’s important information for readers trying to interpret health studies.
Same thing in coverage of the story on the New York Times blog, which was entitled Home births pose special risks. No discussion of the maternal outcome findings, and here they didn’t even mention the low absolute occurrence of neonatal complications.
The coverage in Medical Daily was even more alarmist: Home births linked to increased neonatal complications; Mothers should plan for emergency hospitalization. While planning for possible transport to the hospital certainly seems wise, including “plan for emergency hospitalization” in the title didn’t really seem to follow from this study’s findings.
So why did the media ignore the maternal half of the paper? Is it just the fact that home births involve a lower level of intervention is old news? Or do maternal risks not matter very much to the general public when babies are involved? I’d be curious to hear what other people think about this!