CDC Statistics

The CDC has finally gotten an on-line searchable query for 2003-2004 linked birth-death infant records. If you’re into this sort of thing, you can look at the stats based on so many different factors — age of mother, gestational age of baby, race, mother’s marital status, etc. You can look at the cause of death and age of infant at death (from 1 hour old, up through 1 year old).

I have a problem with it, though. I’ve been fiddling with different variables, and decided to look at all births attended by “other midwife” (that is, a non-nurse midwife), grouped by gestational age and cause of death in the neonatal period. Anyway, it shows eleven deaths from 20-35 weeks of gestational age. I’ve never heard of midwives intentionally attending births that occur prior to 35 weeks! It makes me wonder if the information was entered accurately.

Also, one can search for infant/fetal deaths that happened prior to 20 weeks of gestational age, and actually lists that some survived! What? As far as I know, the most premature infant to have survived was born at 21 weeks and 6 days of gestation — no baby has survived born earlier than that, much less born prior to 20 weeks! Specifically, there were 1570 births; and 532 babies died before the baby was an hour old; 700 did not live a full day; 40 did not survive a full week; 15 died before they lived a month; and 18 died after 28 days but prior to 1 year. This leaves over 250 babies who supposedly were born prior to 20 weeks of gestation and survived their first year. I’d love it if it happened, but I don’t think it happened. (It’s possible that the discrepancy is due to “weighting” — that is, inability to link 100% of death and birth certificates… but it seems that 250+ is more than the “small difference” implied by the CDC.)

Just for kicks, I looked up births by delivery method, and it has CNMs listed as the attendant for over 5000 C-sections. Except, midwives don’t do C-sections! Does this mean that the “birth attendant” is the person who was the first person (doctor or midwife) to care for the woman in labor? So, even if a non-nurse midwife appropriately transferred care of difficult cases (such as the above pre-term births), she would still be listed as the birth attendant? This would make sense, since “other midwife” is listed as the birth attendant in some 4,000 hospital births, including several of the preterm births. However, only CNMs are allowed to practice in hospitals. So that’s confusing — was care transferred from non-nurse midwives, although they are still listed as the attendant? or are the records even accurate?

You know, I thought that having this data would make things clearer, but instead it seems that it’s just getting muddier and muckier.

Anyway, if this sort of thing interests you, you can fiddle with the numbers yourself and see what you can find. It is good to look at the numbers behind the numbers — as I did above, when noting the apparent discrepancies of non-nurse midwives attending hospital births, and CNMs as the birth attendant at C-sections. It’s also important (in my opinion) to exclude certain causes of death, because it isn’t really fair to count infant deaths due to helicopter crashes and other accidental deaths or intentional murders, you know? I think it’s also important to note that many deaths were due to congenital malformations and genetic defects. While it’s possible that some of the babies born at home might have survived had they been born at the hospital, unless we know the story behind the bare numbers, it’s just conjecture.

I would also mention that some numbers may be apparently worse for home-birthers, if the mother either didn’t know about a baby with genetic or physical malformations, or she knew about it and refused an abortion, and also declined to go to a hospital. For instance, most of the home-birthing women I know decline ultrasounds and other prenatal testing, so would have no idea that their babies were at greater risk for or definitely had a problem such as Trisomy 13 (Patau Syndrome) or anencephaly. This lack of knowledge could affect the numbers in two different ways — first, there would be no reason for the mother to have an abortion; therefore, more of these babies would statistically be born (since many women opt to terminate the pregnancy once they find out that the baby has a problem). Second, these babies would be (possibly) poor candidates for a home birth, but that would not be known prior to birth, so it skews the numbers for normal births.

One other term to consider is “induced preterm birth” which is also called a live-birth abortion. Essentially, the mother is induced so much preterm that the baby cannot survive (and no measures are taken to keep the infant alive). Whether these numbers are included or not is unclear. Abortions are not counted in perinatal mortality, since they are intentional fetal deaths; however, these babies were born alive, but with the intent of their death. That may be part of the answer of the midwife-attended early preterm births and fetal deaths — these women may have found out that their babies had some genetic defect or congenital abnormality and chose a preterm induction as the way to end their pregnancies, and perhaps asked the midwife to be with them at the time.

See what I mean about the story behind the numbers? There are so many possibilities!

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2 Responses

  1. Ahh, the joy of statistics. Manipulate the numbers to make them say what you want. Or just get horribly confused by what the numbers could or are saying.

  2. [...] midwife, midwifery, neonatal mortality — Kathy @ 3:01 pm Previously, I had written this post about the CDC statistics for neonatal and infant mortality for the years 2003-2004. It included a link to the online [...]

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