Tuesday, February 4, 2014

MANA Study: Comparing Mortality Rates


For a more in-depth look at the MANA numbers, click here to read my series.

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I wanted to get a closer comparison for looking at the rates between the hospital group and the MANA study.

The neonatal mortality rate for the USA as a whole is 4.0/1000. However, this is for any live birth, regardless of gestational age, regardless of risk, regardless of lethal anomalies. So it includes extreme prematurity, high risk moms, etc etc... every complication you can think of. This is clearly not the appropriate number to use for full term babies.

So I used the CDC Wonder Database (http://wonder.cdc.gov/). My search was based on the following criteria to match the MANA study as close as possible:

White women
Singles and twins
37 weeks and above
Birth weight of 2500 grams or more
Live birth through 27 days (the neonatal period)
Years 2004-2009
It includes everything else… all ages, all education levels, all marital statuses, etc

Here are the rates based on that criteria:

Years 2004-2006










Years 2007-2009







Average those numbers and here are our rates:

Hospital MD neonatal mortality rate = 0.62/1000
Hospital CNM neonatal mortality rate = 0.38/1000

(CNMs will care for mostly low risk, which is why their numbers are lower. The MD group is low risk and high risk. These numbers include lethal anomalies.)

Now to compare…

MANA STUDY:
Intrapartum mortality rate = 1.30/1000
Intrapartum mortality rate for low risk only = 0.85/1000
Neonatal mortality rate (excluding lethal anomalies) = 0.77/1000

HOSPITALS:
Intrapartum mortality rate = 0.1/1000-0.3/1000
Neonatal mortality rate for low risk (including lethal anomalies) = 0.38/1000
Neonatal mortality rate for low risk and high risk (including lethal anomalies) = 0.62/1000

TOTAL MORTALITY RATES (intrapartum plus neonatal):
MANA study = 2.07/1000 (excluding lethal anomalies)
MANA study for low risk = 1.62/1000 (excluding lethal anomalies)
Hospital rate for low risk = 0.48/1000 to 0.68/1000 (including lethal anomalies)
Hospital rate for low risk and high risk = 0.72/1000 to 0.92/1000 (including lethal anomalies)


Now let’s include lethal anomalies in the home birth numbers to have a better comparison since we cannot completely exclude them from the hospital group… so ALL numbers below include lethal anomalies:

MANA STUDY:
Intrapartum mortality rate = 1.30/1000
Intrapartum mortality rate for low risk only = 0.85/1000
Neonatal mortality rate = 1.29/1000

HOSPITALS:
Intrapartum mortality rate = 0.1/1000-0.3/1000
Neonatal mortality rate for low risk = 0.38/1000
Neonatal mortality rate for low risk and high risk = 0.62/1000

TOTAL MORTALITY RATES (intrapartum plus neonatal):
MANA study = 2.59/1000
MANA study for low risk = 2.14/1000
Hospital rate for low risk = 0.48/1000 to 0.68/1000
Hospital rate for low risk and high risk = 0.72/1000 to 0.92/1000

This is an even closer comparison than listed above since we are now comparing apple to apples by including lethal anomalies. A low risk baby is 3 to 4.5 times more likely to die at a home birth than in the hospital. This means for every 10,000 babies born at home (to low risk mothers), 15-17 will die that would have lived had they been born in the hospital.

Part of the problem with home birth midwifery is that screening measures aren’t always taken (and in many cases, are not encouraged) to ensure a low risk woman remains low risk. If a pregnant woman planning a home birth does not take screening measures recommended to make sure she is low risk throughout her pregnancy and just assumes she is low risk (or if her known high risk pregnancy is not referred out and simply referred to as a “variation of normal”), then you are looking at comparing the low risk hospital numbers to the numbers in the MANA study that represent all women, which would mean a baby is 4-5.5 times more likely to die at home vs in hospital. This means for every 10,000 babies born at home, 19-21 will die that would have lived had they been born in the hospital.

Here are some other important rates from the study:

HIGH RISK MORTALITY RATES (intrapartum plus neonatal):
Home birth VBAC = 4.75/1000
Home birth twins = 8.33/1000
Home birth breech baby = 22.67/1000

MANA did not offer numbers for comparison in their study. Every woman has a right to this information.

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UPDATE 03/04/2014:

(update made due to comment below)

There is an option on the CDC Wonder Database to exclude most lethal anomalies. It does not include *all* lethal anomalies, though, as certain congenital anomalies that are lethal may be labeled as something else like cardiovascular disease. So keep in mind, the hospital rates are likely even lower. 

Hospital rates, excluding most lethal anomalies:
Neonatal mortality rate for low risk = 0.25/1000
Neonatal mortality rate for low risk and high risk = 0.33/1000

Again, MANA study rate, excluding lethal anomalies:
Neonatal mortality rate = 0.77/1000

Total rates, excluding anomalies are:

TOTAL MORTALITY RATES (intrapartum plus neonatal):
MANA study = 2.07/1000
MANA study for low risk = 1.62/1000
Hospital rate for low risk = 0.35/1000 to 0.55/1000
Hospital rate for low risk and high risk = 0.43/1000 to 0.63/1000

ALL RISK:
All risk hospital birth (low plus high risk pregnant women) compared to all risk home birth (low plus high risk pregnant women) = 3 to 5 times more likely that a baby will die at home. For every 10,000 babies born at home, 14-16 babies will die that would have lived had they been born in a hospital.

LOW RISK:
Low risk hospital birth compared to low risk home birth = 3 to 5 times more likely that a baby will die at home. For every 10,000 babies born at home to low risk moms, 11-13 babies will die that would have lived had they been born in a hospital.

ALL RISK to LOW RISK:
If a woman having a home birth assumes her low risk status (instead of confirms her low risk status by taking all screening measures to ensure she is truly low risk) and/or if her high risk pregnancy is brushed off as a "variation of normal" and/or if her midwife does not recognize certain complications due to ignorance or lack of screening/monitoring during pregnancy or during labor/delivery, then we would compare low risk hospital birth to the MANA study numbers representing low AND high risk. Which means:
A baby is 4-6 times more likely to die at home. For every 10,000 babies born at home, 15-17 will die that would have lived had they been born in a hospital.

Excluding anomalies, there is still a very significant risk to babies born at home.

Screen shots of the CDC Wonder Database results:

2004-2006:

2007-2009:



For a more in-depth look at the MANA numbers, click here to read my series.


3 comments:

  1. I am glad you posted this. I was following you on babycenter and I think that Group Owner deleted the blog thread. How is that for benefitting their followers. Keep up the good work.

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  2. Assuming that the birth rate of babies with lethal anomalies is similar in a hospital/doctor setting vs midwife/homebirth setting is fallacious. It stands to reason that a woman would be less likely to terminate a pregnancy for those reasons if planning a homebirth with a midwife than in the hospital with a doctor. In a medical setting they are more likely to push or encourage termination. These numbers would not be reflected in their final numbers. But I think we can definitely figure that the rate of termination is more likely to be higher with more frequent ultrasounds, etc. There's also tremendously less support for a woman who wants to carry her child with lethal anomalies to term in that kind of a situation. I think more data is needed, particularly from the obstetric side.

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    Replies
    1. There is an option in the CDC Wonder Database to exclude most lethal anomalies. Doing so and the mortality rates become:

      Hospitals:
      Neonatal mortality rate for low risk = 0.25/1000
      Neonatal mortality rate for low risk and high risk = 0.33/1000

      Compared to the MANA study, excluding anomalies:
      Neonatal mortality rate = 0.76/1000

      Risk is the same with anomalies excluded: Three times higher for low risk and over two times higher for low and high risk.

      However, certain anomalies may be labeled as something else like cardiac disease. So the hospital rates excluding anomalies is likely even lower.

      I'm also not all that convinced certain deaths in the home birth group would be considered lethal anomalies. A baby born with a severe defect in the hospital has a better chance surviving with immediate access to life saving equipment.

      Certain women in the home birth group may have also transferred care to a high risk doctor for their pregnancy if a severe defect is discovered during the pregnancy.

      Regardless, your theory does not hold up. As I have shown here, even with (most) lethal anomalies subtracted from the hospital group, risk is still higher at home.

      I will add these numbers to my blog post here, though, with screen shots so you can see for yourself.

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