Birthplace Study - Is Homebirth Twice As Dangerous for First-Time Moms?

[rachieface]

A fascinating British study just came out that is one of the most comprehensive homebirth studies yet to date.  64,538 women with no known risk factors were studied and their outcomes were recorded according to birth place.  First time moms had about double the chance of stillbirth when having their babies at home as compared to the hospital.  Multiparas, however, had similar if not better outcomes at home.  Here's the link to the abstract: http://www.bmj.com/content/343/bmj.d7400

So, what do you think?  If low risk first-time moms with well-educated midwives (working with the NHS) have double the chance of stillbirth at home, would women with any risk factors have a higher risk of bad outcomes?  Also, does this demonstrate an enormous difference between an unproven pelvis and a proven one?  Why the big difference? 
 

I'd love to hear some other women's thoughts on this study, as I'm considering a homebirth for a (not yet conceived) second child.  I like the results of this study for my case, but worry about what it says about nulliparas (or high risk women) having homebirths.  Thoughts?

[Storm Bride]

I don't know about the doubled risk of stillbirth in first-time moms. But, I suspect part of the reason why the difference disappears for multiparas is that "low risk", for a multipara, would only apply to moms who had already made it through a first pregnancy without running into any problems. One of the factors that affects whether a woman is labeled "low risk" or not is whether there's a pre-existing history of a variety of issues (eg. pre-e, prematurity, precipitous labour, etc.). A "low risk" nullipara is basically a pregnant woman with no current identifiable risk factor. A "low risk" multipara is one with no identifiable risk factor in either the current, or previous pregnancy/pregnancies. (That's a slight oversimplification, but not much of one, ime.)

[cameragirl]

One answer to the risk of still birth is that midwives are much more likely to let labor happen naturally. Statistically, the longer the pregnancy, the higher the risk of still birth. Of course, that says nothing about neonatal deaths that may have happened due to early inductions and c-sections.

I strongly feel that home birth is a good choice for those that are low-risk and comfortable with birthing at home. I wish that I would have gone that way or used a FBS with my first.

[Rubina]

Hi,

I think we should also remember, that comparing a home birth to a birth in an obstetric unit in Britain with a normal birth rate of 50% is a diferent thing, than comparing it to a birth taking place in an American obstetric unit, where I think the normal birth rate is most probably much lower. What I'm trying to say is, that birthing a baby in a hospital in UK is probably a healthier and safer option compared to birthing a baby in a US hospital.

So, to use this study's findinds to know the safety of homebirth in US, the findigs would really need to be compared with the birth stats of US hospitals.

[AlexisT]

Originally Posted by cameragirl 

One answer to the risk of still birth is that midwives are much more likely to let labor happen naturally. Statistically, the longer the pregnancy, the higher the risk of still birth. Of course, that says nothing about neonatal deaths that may have happened due to early inductions and c-sections.
I strongly feel that home birth is a good choice for those that are low-risk and comfortable with birthing at home. I wish that I would have gone that way or used a FBS with my first.

These women would have had the same type of midwives in all settings. Low risk births on the NHS are always midwife attended (in a CU, OBs are present but only called in if needed). All midwives involved were trained in the same way and employed by the NHS. I do not know if independent midwives were included (also NHS trained but not employed). Indies tend to take on higher risk cases but these would have been excluded. Independents only do a fraction of home births anyway. NHS home birth midwives operate according to centrally set protocols.

The transfer rate is high but includes risk-outs as well as intrapartum transfers, since the groups were done on intended place of delivery at booking to keep transfers from artificially inflating the hospital outcomes. It would be useful to separate it again by place of birth at start of labor--if you get risked up to consultant at 20 weeks for high blood pressure, that doesn't say much about where you intended to birth in the first place. I read that transfers prior to labor were 35% but I don't know if that's 35% of 45% (meaning 29% of first timers were transferred intrapartum), or 35% of all women (leaving a 10% intrapartum rate). Since first time mothers have higher rates of some complications such as preeclampsia, and are effectively untested (pelvis and otherwise) their group simply isn't as well selected as the multip group. All the multiparas in the study were not only low risk for this pregnancy, but had successfully passed the hurdle the first time without complication. They were probably the lowest risk obstetrical group you could find. Unfortunately, because we can't predict that and because complications can occur at any turn, I think the outcomes for the first time group will always be worse.

What may happen with these findings is that they begin discouraging first time mothers from delivering anywhere but a consultant unit. There are units that discourage anyone who does not meet a perfect risk profile from delivering in them.

This study ruthlessly stripped out every risk factor it could find, even GBS status (I wonder if they swabbed; it's not routine on the NHS, only urine screen). So, this doesn't say much directly about higher risk home births. However, even with the lowest risk group possible, they got equal outcomes aside from interventions. That doesn't bode well for adding risks back in.

[AlexisT]

Slight correction: >= 37 weeks gestation was a criterion for inclusion, so I assume anyone who got risked out like that would be excluded completely, which makes the comparison better. Still, you can get risked out at 37 weeks plus. Also, it doesn't mention a postdates cut-off--my trust's policy was that you were referred upwards (and generally booked in for induction) at 41+5.

Also, looking at the BMJ full text, stats were collected through NHS trusts, so independents should've been excluded--though I know someone who used one who was also booked in through the NHS so she could get her free tests and scans.

[RosieL]

I read the study and looked through the tables. They did not measure stillbirth outcomes individually, but rather "primary" outcomes, which was a composite measure of several different kinds of adverse perinatal outcomes. Unless I mis-read, this study does not present the differences in stillbirths alone.

That being said, the study is extremely frustrating. There is no theory or investigation into why the differences between nulliparous home and OB outcomes occurred. The most obvious difference between the home and freestanding birth center demographics would be distance from a hospital. Was this a factor? If not, what was? I hope to see follow-up analysis. Otherwise this study is extremely frustrating because it says nothing about the WHY of its findings.

Also, most of the confidence intervals for odds ratios were close to one on the low side...

[AlexisT]

An FMU might be just as far from the hospital as home. I have friends who used one. 2 required transfer. It meant an ambulance ride in London traffic. AMUs (in hospital birth centers) did better than FMUs. 

BTW, perinatal mortality is actually higher in the UK than US. 

Other interesting fact: the home birth group was noticeably whiter and wealthier. BME women are known to have higher rates of complications. 

[starrlamia]

the perinatal mortality rate is not significantly different in the UK from the USA.

[AlexisT]

It is slightly higher. Not hugely. My point was that you can't make generalizations about how hospital birth in the UK is safer, which someone implied above. Mortality statistics do not correspond to general levels of intervention in birth, not even on a curve (where interventions improve outcomes up to a certain point, but fail to do so after that).

[AutumnAir]

Just thought I'd link to this article which discusses the study. 

[rachieface]

Thanks everyone for your thoughts. 

Autumn Air - That post was interesting.  As a doula, I resonate with much of it.  I totally agree that women should have choices in childbirth (which they do).  However, I do not like that she seems to minimize the doubled incidence of stillbirth in the homebirth group.  Less than 1% may not seem like a lot, but its everything if you are a woman who loses her child.  The increased chance of negative outcomes at home are nothing to make light of.  I try to share evidence based information with my clients, and here the evidence strongly points to hospital birth being safer for nulliparous women.  That is something that merits discussion and concern among homebirth activists. 

[RosieL]

Thanks AuthumnAir.

As I read it, the author from the review post speculates that there is more variation in procedures and continuity of care for homebirths than in other settings, and that this may cause the higher incidence of adverse perinatal outcomes in home births. I don't see how that would be different between first-time mothers and 2nd+ time deliveries. It would make sense, however, if the lack of skill/comfort of the midwives would only manifest in nulliparous women since women who have already given birth probably self-select out of planning homebirths after having complications. 

Basically, it's speculation, and we can't know anything until more research is done. :( As a first-time pregnant women in the US the study concerns me slightly, but not enough to change my birth plans (homebirth).

[mirandamiranda]

Just to point out that it is not the risk of stillbirth that is doubled, but the rate of negative outcomes for the baby, of which stillbirth/neonatal death are the most serious. The full list of outcomes is: "stillbirth after start of care in labour, early neonatal death, neonatal encephalopathy, meconium aspiration syndrome, brachial plexus injury, fractured humerus, or fractured clavicle". I have not been able to find any details on what percentage each outcome is of the total. Some of these outcomes however will be relatively minor, as the study notes, such as mild encephalopathy which "has not been associated with detectable longer term impacts".

I do agree that a higher rate of negative outcomes, whatever they are, and especially the more serious and tragic ones, is a serious issue. However I would agree with the Hackney Doula that it should be seen as a prompt to find out why this occurs and attempt to close the gap, rather than automatically dismiss homebirth for first-time birthers. There are a variety of possible reasons why this could be the case, and without knowing more we cannot make assumptions and homebirth per se.