Homebirth midwives and rampant Apgar inflation

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We’ve all suspected it. We’ve all seen the homebirth photos of hideously blue babies given high Apgar scores by homebirth midwives. Now comes confirmation that Apgar inflation is rampant among homebirth midwives.

In a new paper, Justified skepticism about Apgar scoring in out-of-hospital birth settings published in The Journal of Perinatal Medicine, Grunebaum et al. looked at 13,830,531 singleton term deliveries delivered from 2007 to 2010 in a hospital, a birthing center, or at home by either a physician, a CNM, or another midwife, and who had a 5 min Apgar score documented.

They found:

Newborns delivered by other midwives or certified nurse midwives (CNMs) in a birthing center or at home had a significantly higher likelihood of a 5 min maximum Apgar score of 10 than those delivered in a hospital [52.63% in birthing centers, odds ratio (OR) 29.19, 95% confidence interval (CI): 28.29 – 30.06, and 52.44% at home, OR 28.95, 95% CI: 28.40 – 29.50; CNMs: 16.43% in birthing centers, OR 5.16, 95% CI: 4.99 – 5.34, and 36.9% at home births, OR 15.29, 95% CI: 14.85 – 15.73].

This is both surprising and important since the Apgar score is not discretionary. There are strict criteria for assigning Apgar scores, as the chart below demonstrates, and we would expect only a very few Apgar scores of 10 regardless of setting because normal neonatal physiology means that most babies will have blue extremities for a significant amount of time after birth.

Apgar scores

As the authors explain:

Our study shows an inexplicable bias of high 5 min Apgar scores of 10 in home or birthing center deliveries. Midwives delivering at home or in birthing centers assigned a significantly higher proportion of Apgar scores of 10 when compared to midwives or physicians delivering in the hospital. Studies that have claimed the safety of out-of-hospital deliveries by using higher mean or high cut-off 5 min Apgar scores and reviews based on these studies should be treated with skepticism by obstetricians and midwives, by pregnant women, and by policy makers.
The continued use of studies using higher mean or high cut-off 5 min Apgar scores, and a bias of high Apgar score, to advocate the safety of home births is inappropriate.

That’s a nice way of saying that homebirth midwives are either incapable of accurately assigning Apgars scores or deliberately inflating them.

Interestingly, a homebirth midwifery executive has also noted this inexplicable bias and ascribed a similar cause.

Melissa Cheyney, Liar-in-Chief of the Midwives Alliance of North America (MANA) in her role as Director of Research has invoked the incompetence of homebirth midwives in an effort to dismiss previous studies that have demonstrated an increased death rate at homebirth over comparable risk hospital birth. In Cheyney’s recent bizarre opinion piece in the Lamaze journal Birth: Issues in Perinatal Care alleging a “crusade” against homebirth, she writes:

There appear to be real differences between how physicians and home and birth center midwives perceive and report Apgar scores at the edges of the Apgar spectrum. Physicians are more likely to report fine gradations of either very low or very high Apgar scores, whereas home and birth center midwives are more likely to report Apgar scores of 0 or 10 more absolutely.”

In other words, Cheyney is insisting that homebirth midwives aren’t presiding over more deaths, they’re just stupid. Homebirth midwives deliver babies that are either better or deader than those delivered in hospitals because they are can’t accurately assign Apgar scores. But the reality is that there are no “fine gradations” of Apgar scores; there is no discretion in assigning Apgar scores of 0 or 10; and there are no differences in “perception” of neonatal death or a vigorous, completely pink newborn.

As poorly educated and poorly trained as I believe homebirth midwives to be, even I cannot imagine that they are mistakenly diagnosing babies as dead when they are not dead. And the only remotely plausible reason for more Apgar scores of 10 among a population that has a greater number of deaths than expected is rampant inflation of Apgar scores by homebirth midwives.

The bias of tendency of homebirth midwives to assign higher Apgar scores than warranted was anticipated by Virginia Apgar herself in recommending that the Apgar scores be determined by someone other than the person who delivers the baby:

Dr. Apgar herself anticipated the potential for bias in scoring when she stated: “ it is strongly advised that an observer, other than the person who delivers the infant, be the one to assign the score ” and “ … experience has demonstrated that the person delivering the infant should not be the one to assign the score. He or she is invariably emotionally involved with the outcome of the delivery and with the family, and cannot or unconsciously does not make an accurate decision as to the total score ” .

And indeed, the key difference between the assignment of Apgar scores at home and in the hospital is that at homebirth the midwives assign the Apgar score whereas the hospital nurse assigns the score in the hospital, eliminating the tendency to artificially inflate the score.

The authors conclude by calling into doubt the results of homebirth studies that use mean Apgar scores to “demonstrate” the safety of homebirth:

… [S]tudies that have claimed the safety of out-of-hospital deliveries by using higher mean or high cut-off 5 min Apgar scores and reviews based on these studies should be treated with sustained skepticism by obstetricians and midwives, by pregnant women, and by policy makers. The continued use of studies using higher mean or high cut-off 5 min Apgar scores and a bias toward high Apgar score to advocate the safety of home births is inappropriate.

There is simply no question that homebirth midwives are biased in assigning Apgar scores. Why? Cheyney says that it’s because homebirth midwives are stupid. Grunebaum implies it is because homebirth midwives don’t tell the truth.

Idiots or liars, take your pick, but either way, homebirth midwives are incompetent practitioners. It is hardly surprising then that all existing research on American homebirth (including MANA’s own statistics), all state statistics, and all CDC national statistics shows that homebirth with a non-nurse midwife dramatically increases the risk of neonatal death.

Thinking about homebirth? Perhaps you should think again.