Sunday, August 28, 2011

Homebirth Research: Another Side of the Story

Information about this has been showing up everywhere for me lately, though I have not sought it out intentionally, and I feel like I would be irresponsible not to write about it.

For a long time, I stayed away from the topic of homebirth, partly because it is such a controversial topic. I have only started writing about it recently because I am pregnant and currently am under the care of a team of homebirth midwives. My post titled "How Homebirth Benefits Babies" was the first post I wrote that "promoted" homebirth (with caveats!). It is also has been the most widely read, currently at 1,788 pageviews.

I have discovered that the evidence really is not clear on the most important point I make in that post when I talk about homebirth research. My words:
First of all, and most importantly, the outcomes that have the highest significance are perinatal mortality and morbidity, because all mothers want a living baby who is not permanently disabled. Research indicates that babies of low risk women who plan homebirths under a supportive system with a qualified attendant are statistically no more likely to die or have serious injuries than babies of similar women who choose hospital birth (1, 2, 3, 4, 5, 6).
It has come to my attention that the results of one of the studies I cite in that post has been called into question by the results of another study--a study that nobody in the online natural birth community appears to be talking about, even though it was published 9 months ago.

The study I cited in my post was the de Jonge study from the Netherlands, which compared outcomes of home and hospital births attended by Dutch midwives among women classified as "low risk" by the Netherlands maternity care system. De Jonge found no difference in mortality or severe morbidity in the home and hospital groups.

The Evers study, Perinatal mortality and severe morbidity in low and high risk term pregnancies in the Netherlands: prospective cohort study was published in the British Medical Journal in November 2010. It compared outcomes of term births classified as "low risk" by the Dutch system attended by midwives (primary care) with outcomes of births classified as "high risk" and attended by obstetricians (secondary care). It found higher rates of perinatal mortality in the primary care group, and no difference in rates of level 3 NICU admission (the measure the study used for severe morbidity). Yes, you read that right. More low risk babies died. There were 26 delivery-related perinatal deaths out of 18,686 who began labor in primary care(a rate of 1.39/1000) and there were 10 delivery-related perinatal deaths out of 16,739 who began labor in secondary care (rate: 0.60/1000). The transfer rate from primary care to secondary care during labor was 22.9%, and 12 if the delivery-related deaths occurred in those who were transferred. The number of intrapartum stillbirths was also higher in the group that began labor in primary care. The study excluded all instances of congenial anomalies.

This study calls into question the belief that the best and safest care for low risk births is low-intervention care. From the Discussion section of the paper:
This seriously questions the supposed effectiveness of the Dutch obstetric system that is based on risk selection and obstetric care at two levels. Of major concern is the fact that the highest mortality was among the infants of women who were referred from primary care to secondary care during labour because of an apparent complication. Hypothetically, this high mortality could have several causes. Delay can occur at three moments. Firstly, diagnosis in primary care can be delayed because the midwife is not always present during the first stage of labour and fetal heart beats are often checked only every two to four hours. Secondly, transport can delay treatment in case of an emergency. Finally, a delay can occur because the obstetrician underestimates the problem as the referred woman is a “low risk” patient. In addition, essential information can be lost during the referral. These factors should be subject to further investigation, especially to evaluate whether complications with the potential to lead to perinatal death can better be predicted.
And this is in the Netherlands, where there is a universal standard for midwife education and there is supposedly to be a good system of transfer of care. Would having low risk women also be cared for by obstetricians be a better system for the Netherlands? That is basically what we have in the U.S., and we have a 33% cesarean rate. Cesareans increase the risk of maternal morality (see Deneux-Tharaux, 2006), though maternal mortality occurs much less frequently than perinatal morality does. Considering the increased risks associated with pregnancies and births in women with prior cesarean sections (see Kennare, 2007) , some of which impact both the mother and baby, I just don't see how this can be the optimal way to care for mothers and babies either. I'm not even going to try to answer the question of how many mothers (and any future babies they may have) should have to accept the risks of a cesarean section to save the life of one baby. It is something to think about.

The choices we have are between sets of risks. The absolute risk of a baby dying at all is low, especially if there is access to fetal monitoring and some level of emergency care (such as midwives who can perform neonatal resuscitation). When are talking about a rate of 1.39/1000, it means an individual has a 0.139% chance of it happening (and a 99.861% chance of it not happening)--and that's all primary care deaths in the Evers study, including ones who would have died no matter what kind of care they received. The risk of preventable death is presumably lower, though we don't know how much lower because there is no obstetrician-attended low-risk comparison group in the study. I don't want it to seem like I am trying to "explain away" the risk of preventable death. The statistics mean nothing when your baby is the unlucky one who dies. I believe in informed choice, and I believe you need accurate information to make informed choices.

After I wrote this post and was waiting to publish it (I usually space posts out further, but I moved this one up because I felt I needed get it out there), I saw this post from Birth Without Fear in my facebook newsfeed, and felt it applied to what I am trying to say. Like her, I am not here to advocate that you have a homebirth. I advocate that you look at the information, weigh your options, and make whatever is the best decision for you.


  1. I appreciate this post. As I was reading, I was thinking, "It's not really about trying to prove whether home birth or hospital birth is better or safer than the other. It's about being informed. It's about knowing correct information, even correct statistics and weighing your options. It's about knowing what risks you are willing to take." And then I read, "The choices we have are between sets of risks."

    Even if it appears that hospital birth might be "safer" according to those studies, even if that is true, in my mind, it doesn't take away from the fact that home birth is a great option!

  2. So three delays mentioned 1) because no one is there during the early stages

    2) because transport takes too long

    3) because the OB's are reluctant to accept the midwife's diagnosis.

    I'd say of the three only one is really applicable to homebirth. (transport) The first one would be a problem with any kind of birth since early stage usually happens at home anyway, and the third one is a problem of communication and acceptance within the birthing professional community. Something that only sincere efforts at understanding and teamwork on both sides can ameliorate.

    This makes birth in the US even more worrying since the state of the relationship between midwives and OB's can be downright hostile.

  3. "Cesareans increase the risk of maternal morality (see Deneux-Tharaux, 2006)"

    No, that's not what that study shows. It shows that mothers who died were more likely to have had a C-section. But they were also more likely to have had a pre-existing medical condition or a pregnancy complication for which C-section was the appropriate treatment.

    In other words, the C-section was done in an attempt to save the mother's life and it didn't work. That's entirely different than saying that a C-section unexpectedly led to the death of the mother.

    Your statement is kind of like claiming that people who die in hospitals are more likely to have been in the ICU. That doesn't mean that the ICU causes deaths. It happens because the sickest people are in the ICU and those are the ones most likely to die.

    Kimberley says:

    "3) because the OB's are reluctant to accept the midwife's diagnosis"

    No, that's not what the paper says. It says that the delay occurs because the midwife fails to make the diagnosis until a full blown emergency develops.

  4. The authors of the study on maternal mortality made the following attempts to control for pre-existing conditions and pregnancy confounders:

    "Deaths that occurred after a multiple
    birth were excluded."

    The study excluded these two groups:

    "1) deaths due to chronic conditions present before pregnancy (including diseases of the circulatory system, hematologic diseases, diseases of the respiratory system, mental disorders, disease of the digestive system, neoplasms, and chronic infections, n=44)"


    "2) deaths due to obstetric conditions that developed during pregnancy but before delivery (including hypertensive disorders in pregnancy, hemorrhage due to placenta praevia or accreta and abruptio placenta, amniotic fluid embolisms, cerebral venous thrombosis, intracerebral hemorrhage, chorioamnionitis, n=64)"


    "deaths in women who were hospitalized during pregnancy were further excluded, because this characteristic was considered a marker of serious antenatal morbidity"

    After excluding these numbers from the data,

    "the risk of postpartum death was 3.6 times higher after cesarean delivery than after vaginal delivery."

    The authors of the study place blame for transfer-related deaths on both midwives and obstetricians. They say that midwives could have delayed diagnosis by, for example, not checking heart-tones frequently enough, but it also says that obstetricians could be "underestimat[ing] the problem" because the patient is "low risk." All of this is the authors' speculation--they don't know exactly what happened in these cases any more than we do.

  5. "The authors of the study on maternal mortality made the following attempts to control for pre-existing conditions and pregnancy confounders"

    Yes, they did, but there are many other diseases that they did not exclude. The lists are not exhaustive. For example, they do not include women who have kidney disease or are substance abusers, both of which increase risk of complications.

    "They say that midwives could have delayed diagnosis by, for example, not checking heart-tones frequently enough, but it also says that obstetricians could be "underestimat[ing] the problem" because the patient is "low risk." All of this is the authors' speculation--they don't know exactly what happened in these cases any more than we do."

    That's right. That part is speculation. However, if patients are dying after being transferred to obstetricians, it is more likely that they weren't transferred in a timely fashion than that the obstetricians ignored the patients symptoms and clinical course.

  6. Brittany, I have to say I'm very impressed at your willingness to look at this subject critically. So many times people's minds are completely closed concerning out-of-hospital birth. The Evers study IS a shocker, and I think you're the first natural childbirth blogger to address it. Brava!

  7. Imo, what it comes down to is how the mother feels, what she feels is safe and where she is comfortable. There's is nothing like a mother's intuition and I think women need to listen to that when decided where to birth instead of just going along with what everyone else is doing... whether that be home or hospital birth. And if you're religious that is where the power of prayer comes in, pray to find out what is right for you.

    Great post, I love your perspective on this.


  8. Juli,

    I have known far too many women whose intuition told them to birth at home, and their babies died or were severely injured as a result. There is nothing like a doctor's expertise, which frankly doesn't even compare to a woman's intuition in my book.

    All of these women felt safe, until they didn't. What does that prove? Nothing.

  9. So the group of women seen by doctors were "high Risk" and the group seen by Midwives were "low risk" and the women were transferred to Doctor care because during labor they were no longer classified as "low risk" what was the percentage that died at home compared to hospital? I think this study also leaves out Consumer choice. Did the women transfer when the midwives felt it was time to transfer? What was the reasons for transfer? Post dates, PROM, Mec, fever, fetal distress, undetected health issues of the mother. There is so much missing from this study in regards to what actually happened. We can speculate in any direction we want, we just don't know

  10. Brittany, after commenting above, I did think of a situation where transported patients might have a higher maternal death rate, even after c/s. If a mother labors for a long time and arrests, and is allowed to continue to labor, C/S can be followed by profound atony. The resulting hemorrhage can be catastrophic.

    This is just speculation, of course.

    attitude devant

  11. . An important limitation of the study is that aggregated data of a large birth registry database were used and adjustment for confounders and clustering was not possible

  12. Besides, delivery related perinatal death is interpreted as a summation of intrapartum stillbirth and obstetrically related death. According to a population based study in Scotland by Pasupathy [3] 60 % of delivery related perinatal deaths were ascribed to intrapartum anoxia and 40% to other causes. This study by Evers et al (table2) showed 12 (85%) intrapartum stillbirths from the 14 delivery related deaths in primary care deliveries, remaining 2 obstetrically (or other causes) related deaths. Similarly, from the 22 delivery related deaths in secondary care 10 deaths (45%) are assigned to intrapartum stillbirths, remaining 10 obstetrically (or other causes) related deaths. This finding is of interest because it is in agreement with what may be expected. After all, obstetrical problems require professional clinical care with unfortunately, a higher expected perinatal death. So, one may conclude that: "the midwives did a good job" by referring to the obstetric clinic correctly. If the authors should have analyzed all the possible associations their conclusions would have been more balanced and more in line with previous studies in the Netherlands that showed no elevated perinatal death or serious perinatal morbidity in low-risk women.[4]

  13. There are no studies that show no evaluated perinatal death in low risk women. The Netherlands has one of the highest perinatal death rates in Western Europe. The Netherlands also has a high and rising rate of maternal mortality. The Dutch government is deeply concerned about both issues.

    The Evers study is one attempt to get to the bottom of the issue and it showed a much higher than expected rate of perinatal death in the low risk group. This is what you would expect if midwifery care were inferior to obstetrician care. Midwives are great when nothing goes wrong, but if something does go wrong it takes too long for the patient to get appropriate help.

    This study does not prove that midwifery care was substandard, but it definitely raises the issue and therefore more study of midwifery care is warranted.

  14. Against the background of the observed perinatal mortality data, a close cooperation or even a fusion between the two levels of care may be the preferred solution. The role of the midwife should not be underestimated and is most likely one of the reasons that the rate of caesarean section is still the lowest in Europe.

  15. Victor J Pop, MD, PhD, professor of Primary Care; Hennie Wijnen, RM, PhD.

    To the editor

    Evers et al conclude in their paper: '' the Dutch obstetric care system may contribute to the high perinatal mortality'' 1. The selective way of inclusion of perinatal death cases in the paper has already been seriously questioned 2. There are, however, several other important comments on the study.

    Primary obstetric care in The Netherlands refers to care by a community midwife for low-risk women and secondary care to care for high-risk women by an obstetrician in hospital, based on strict criteria. However, crucial with regard to Evers conclusions, low-risk women in primary care can deliver at home but also in hospital with a community midwife. In both cases, this is regarded as primary obstetric care. This means that in low- risk women there can be a transition from primary to secondary care during labour when she is already in hospital. Strikingly, the authors do not mention any data on the number of women who deliver at home, who deliver in hospital with a community midwife and who deliver after being referred in hospital from primary to secondary care. But in the discussion section all kinds of possible mechanisms to explain their findings are mentioned without being assessed. One explanation they suggest: ''the community midwife is not present during the first hours after labour started at home''. However, the Dutch Perinatal Registry3 shows that by far the majority of referrals to secondary care occur after the first hours of labour (most often because of delayed dilatation time). ''There might be a time-delay because of transport to the hospital in case of emergency''.

    But how many women who start labour with the community midwife were already in hospital before they were referred to secondary care?

    The best way to answer the question where to confine is to randomize low-risk women to primary or secondary care delivery. It is obvious that no low-risk pregnant woman will accept randomization regarding place of delivery for the benefit of research. An alternative is an ''open'' prospective study in which, as much as possible, important known confounders of peri-natal death are included in the design of the study.

    It is unacceptable that the authors - drawing conclusions which have such an enormous impact in our society - just state in their limitations of the study section that no confounders at all were included (because they did not assess them, so it was not a prospective study as they stated).

    But there is more. The number of low-risk women who starts labour in primary care is 5% higher than the number mentioned in the Dutch Perinatal Registry of 2007. So, were more high-risk women included in the low-risk group? Also, the national registry has shown that during the last decade up to one third of the 25% of all pregnant women who never see a midwife during pregnancy (defined as high-risk) and who deliver in secondary care, in fact are - according to the strict criteria - low-risk women. This means that when applying the national data to the current cohort there were 5% more low-risk women starting labour in primary care as expected while in the high-risk group 8% women in fact were low-risk. We wonder what the differences of peri-natal death figures would have been if only the real low- and high-risk women were included in the analysis. Or is the cohort not representative for the whole country which does not allow the authors to generalize the conclusions?

  16. Ank De Jonge, senior midwife researcher Ben Willem Mol, Birgit Y Van der Goes, Jan G Nijhuis, Joris A Van der Post, Simone E Buitendijk
    Midwifery Science, AVAG and the EMGO Institute for Health and Care Research, VU University Medical C
    With interest we read the study from Evers et al. on perinatal mortality and morbidity in the Utrecht region, one of the 12 provinces in the Netherlands. This is the first study ever to show a higher mortality rate among births that started in primary care compared with secondary care. We have concerns about the methods used.

    First, although the title suggests that this is a prospective cohort study, the entire population at risk has been defined retrospectively and was based on postal codes of the catchment area of one university hospital. All intrapartum and neonatal deaths were included from hospitals and midwifery practices within this area, but potentially not all births. Midwives in practices at the periphery of the catchment area will also care for many women in neighbouring regions. These births have not been included in the study, unless the baby died. This will artificially inflate mortality rates in midwifery practices.

    Second, the study was conducted in only one region in the Netherlands. The intrapartum and neonatal mortality rate was twice as high as in recent national studies among women in primary care at the onset of labour (1.39 versus 0.65 and 0.52 per 1000)1;2. Although classification bias and underreporting may have played a role in these retrospective studies, it is unlikely that half of all deaths would have been missed. In another prospective study of perinatal mortality cases only 3.5% additional cases were found as compared to national registration data 3.

    Strikingly, in Evers' study 67% of all babies that died during labour were born in primary care. This means that either the midwife noticed fetal distress too late to refer a woman because the birth was imminent or a deceased baby was born so fast that the midwife arrived too late to a woman's home. It is very surprising that these situations were much more common than referral before birth. In Amelink's national study, only 5% of intrapartum deaths were among births that took place in primary care 1. This discrepancy suggests that the study sample may be rather different from the national population.

    Given the limitations of the study, the conclusion that labour starting in primary care carries a higher risk of delivery related perinatal death compared to labour starting in secondary care is premature from a scientific point of view. The authors correctly state that "their findings are unexpected and deserve further evaluation". Previous audit studies did not find that features of the Dutch maternity care system were related to preventable perinatal deaths 3;4. The results of Evers' study call for an urgent review of all mortality cases in the audit study announced by the authors. In addition, perinatal outcomes in other regions need to be examined. Ideally, a large national prospective cohort study should be conducted. The suggestion that "the obstetric care system in the Netherlands possibly contributes to the high perinatal mortality rate" can not be made based on these data alone.

    (1) Amelink-Verburg MP, Verloove-Vanhorick SP, Hakkenberg RM, Veldhuijzen IM, Bennebroek GJ, Buitendijk SE. Evaluation of 280,000 cases in Dutch midwifery practices: a descriptive study. BJOG 2008; 115(5):570- 578.

    (2) De Jonge A, Van der Goes BY, Ravelli AC, Amelink-Verburg MP, Mol BW, Nijhuis JG et al. Perinatal mortality and morbidity in a nationwide cohort of 529,688 low-risk planned home and hospital births. BJOG 2009; 116(9):1177-1184.

  17. Yes, there were two letters to the editor from non-obstetricians who disagreed with the study. So what? There are always letters that disagree.

    It's hardly surprising the DeJonge disagrees. This study puts her study into a whole new light. Instead of showing that homebirth is safe, DeJonge's study actually showed that both homebirth and hospital birth with a midwife are equally unsafe.

  18. Brittney-I am very much along your lines of thinking. To me it's about which risks you are willing to take. And that is different for everyone. I don't like to tell women that if they choose one way or the other that it will decrease their risks. For one thing, if you tell a woman that she should have a homebirth because of xyz then she ends of having a baby that has complications. On the other hand, you tell a woman that she should have a hospital birth, she ends up having a doctor that decides she needs a c-section, she ends up with a huge hemmorrage(which are more common in c-sections) and goes to the ICU.

    Good article. Rachel

  19. Just another seems to me that how we transfer women is a big issue. I've seen problems with it here in the US and it looks like it's else where also. In that case the problem is not necessarily where you give birth, but how quickly or smoothly the transfer goes. That can also include the ideas brought up in this post...midwifes transfering too late, doctors not accepting etc. What I think we need to do is work on that aspect as well. I would love to look at the babies that died in the low risk group and see if we could peice together any common factors that would help assist us in knowing when to transfer. Where the babies not monitored well, did the doctors not respond quickly enough(which does happen here in the US, I've seen it-they tend to think that some midwifes don't know what they are talking about and won't move too quickly until they admit and assess a patitient, which can take a long time if they don't feet the need to rush). Also, what was the transfer time for these babies? Did the ones who die happen to live further away from the hospital? There are so many questions to look at in how we can improve just this one small aspect that can make a huge difference in the outcome for mother and baby.



  22. Sometimes it does not matter where you are or who is providing the care...Life and death happen..Midwives provide a type of care that Doctors simply cannot. Often midwives pick things up in care because they take more than 5 minutes of their time with the woman. True collaborative care and accountability within the maternity system between Midwives and Doctors, makes the most sense and would provide the best answer. There is a reason that many women are seeking home birth and Midwives. No one will make this go away, this need to be taken care of and listened to. It is growing stronger and stronger and women are getting angrier by the moment. Provide trained competent Midwives to take care of the women who will not go back to the hospital, or they will find whoever they can get.

  23. Its not surprising that Amy Tuteur disagrees and sees biased interested partys in those who disagree with her.

  24. This is excellent research. I'm curious, how did the birth go?