Study shows home births are not as safe. So?

There’s an interesting example of how to interpret scientific results — and draw policy implications from them — from the world of birth practices and safety.

The subject of the debate is a major new study from the British Medical Journal. The study followed more than 60,000 women in England with uncomplicated pregnancies, excluding those who had planned caesarean sections and caesarean sections before the start of labor. They compared the number of bad outcomes — from death to broken clavicles — for women depending on where they had their births.

One comparison stands out in the results. From the abstract: “For nulliparous women [those having their first birth], the odds of the primary outcome [that is, any of the negative events] were higher for planned home births” than among those planned for delivery in obstetric units. That is, the home births had higher rates of negative events. The difference is large. Here’s a figure to illustrate:

The error bars show 95% confidence intervals, so you can see the difference between home births and obstetric-unit births is statistically significant at that level. These are the raw comparisons, but the home-versus-obstetric comparison was unchanged when the analysts controlled for age, ethnicity, understanding of English, marital or partner status, body mass index, “deprivation score,” previous pregnancies, and weeks of gestation. Further, by restricting the comparison to uncomplicated pregnancies and excluded all but last-minute c-sections, it seems to be a very strong result.

But what to make of it?

In their conclusion, the authors write:

Our results support a policy of offering healthy nulliparous and multiparous women with low risk pregnancies a choice of birth setting. Adverse perinatal outcomes are uncommon in all settings, while interventions during labour and birth are much less common for births planned in non-obstetric unit settings. For nulliparous women, there is some evidence that planning birth at home is associated with a higher risk of an adverse perinatal outcome.

But in what way do the results “support a policy”? The “higher risks” they found for planned home births are still “uncommon,” by comparison, with those in poor countries, for example. But the home birth risk is 2.7-times greater.

The Skeptical OB, who is a reliable proponent of modern medical births, titled her post, “It’s official: homebirth increases the risk of death.” She added some tables from the supplemental material, showing the type of negative events and conditions that occurred. Her conclusion:

“In other words, any way you choose to look at it, no matter how carefully you slice and dice the data, there is simply no getting around the fact that homebirth increases the risk of perinatal death and brain damage.”

I guess the policy options might include include whether home births should be encouraged, more regulated, covered by public and/or private health insurance, banned, penalized or (further) stigmatized.

Home birth seems safer than letting children ride around unrestrained in the back of pickup trucks, which is legal in North Carolina — as long as they’re engaged in agricultural labor. On the other hand, we have helmet laws for kids on bicycles in many places. And if a child is injured in either situation, hopefully an ambulance would take them to the hospital even if the accident were preventable.

In other words, I don’t think policy questions can be resolved by a comparison of risks, however rigorous.

8 Comments

Filed under In the news, Research reports

8 responses to “Study shows home births are not as safe. So?

  1. First, thanks for this post. This is a topic that needs some light on it. But I wonder:

    I don’t think policy questions can be resolved by a comparison of risks, however rigorous.

    by this, you mean comparisons between home birth, car travel, and bike helmets, right? Because comparisons between the risk of home vs. hospital birth, seatbelt vs. no seatbelt, etc., are exactly what we need to use to decide policy questions.

    The home birth issue in particular is swimming in a sea of misinformation, mythology, and conspiracy theory. An analysis of outcomes is exactly what folks need to make good choices, and there is a shortage of U.S. data on this. In Canada, things seem to be a bit safer for home birthers, possibly because of the policy differences. Home-birth midwives here receive more training, are licensed, and work more closely with hospitals.

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  2. Jenny

    While I generally agree with your posts and love the insight you provide, I have to take issue with your statement about evaluating risk. Evaluating risk is exactly what is needed to assess the appropriate public health policy whether that is better training for home birth attendants, better training for emergency personnel who may be required to transport a women during an obstetrical emergency, or better hospital policy that would provide the sort of autonomy and respect that is currently lacking and sends many women running from hospital birth. I think the fallacy would be in assuming that because there is a difference in risk, its some sort of natural law and nothing can be done to lower the risk profile of home birth. Difference in risk alert us to opportunities for intervention.

    Also, home birth in the US is very, very different from home birth in other developed countries and we cannot compare the two. Home birth attendants in countries where home birth is common are very rigorously trained and generally have the full support of the broader medical community. I am a great supporter of midwifery, but I have real concerns about the adequacy of some lay midwives training. Home birth attendants in the US may be very well trained or they may be essentially non-medical providers. Some lay midwives have only attended 40 births before they are licensed. We have created such a hostile climate in the US for home birth attendants that they are often unable to find backup physicians. There is also the very important consideration of the overall health status of the pregnant woman. As we lack universal healthcare and many other health protecting policies, our women enter into pregnancy less healthy that counterparts in the UK or Denmark or any of the other countries where home birth is more common. The US has a maternal mortality rate twice that of other developed countries. Though the risks are small, they are very meaningful when you consider the potential impact on families of maternal and infant injury or death.

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  3. I agree with both of you, Tina and Jenny. What I meant was the risk analysis doesn’t *make* the decision — it provides the information we need to do that. The results don’t really “suggest” a policy. Thank you for the responses.

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  4. kate

    It is curious that homebirth increases the risk of a negative outcome among first time mothers but not multiparous mothers. Is it that multiparous mothers who had a poor outcome with their first birth are less likely to choose/be allowed to have a home birth? If so, could information on what those poor outcomes were and related symptoms of that risk during pregnancy be used to guide first time mothers’ decisions about home births and thus equalize the risk?

    Also, and I haven’t read the original article, even if the pregnancies are “uncomplicated” are women equally as likely to choose a home birth vs. other types? I wonder if first time mothers choosing homebirths have made decisions along the way or are different in some what such that they’re not a comparable group despite statistical adjustment. For example, did the moms who had a homebirth have as good prenatal care or access to ultrasound?

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  5. Michael Bishop

    Though suggestive, this is far from proof of a causal difference between home births and others. The different result for 1st birth and later births in particular raises questions.

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  6. There is still so much unknown data here. For instance, it shows later home births are fine. Does that mean the second birth is easier, or that the parents are more experienced and therefore more capable of catching warning signs of something wrong?

    Also, how many of these first time home births had a midwife on hand? If the answer is none (as seems to be the implication), then are we arguing against birth at home, or births had without professional guidance? What about the area the baby was had in, or the methods the parents were using, or the body type of the mother? How much did those factors come into play for problems with the births? And those are just questions off the top of my head.

    It is far too easy to create a statistic, but much harder to accurately parse the data. This is like saying since a kid has red spots, he must therefore have chicken pox. Many diseases and allergies present with red spots, and finding out what said kid has is what SCIENCE is all about. It’s about looking through every iota of data, looking into every possible factor, and NOT relying on a single symptom to diagnose a disease.

    This is a single symptom. It is indicative of something wrong, no doubt. But to conclude the problem is simply “they had them at home” is hasty and foolish. I’d like to know more before buying this completely.

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  7. Pingback: Home birth is more dangerous. Discuss. | Family Inequality

  8. Pingback: How Dangerous Is Too Dangerous When It Comes to At-Home Birth? | Today Health Channel

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