What does "time of birth" really mean?
November 26, 2008 5:52 PM   Subscribe

What is the official, medical definition of a newborn's "time of birth?"

I'm working on a small statistical analysis relating to childbirth, and I'm wondering what the official "time of birth" of a newborn baby really means? Is it the moment when the baby is fully clear of the mother? The moment the baby takes its first breath? Something else?

I'm trying to figure out how accurate the time of birth recorded on something like a birth certificate really is. Google is not proving very helpful (I'm getting lots of results for astrology sites) and my physician assistant friend isn't online. Can you help?
posted by sjl7678 to Health & Fitness (7 answers total) 2 users marked this as a favorite
I think that time of birth is a bit of a moving target. In reality, it's whatever time the clock says when the nurse first looks up after the complete delivery of a baby. It is definitely not the time of first breath. Some people might say that it's the time the cord is clamped, but this is not specific either - especially since there has been some movement to delay cord clamping for up to an hour.

It is also not realistically the time of delivery of the head itself, because in some unfortunate situations, there can be significant delay between head delivery and the rest of the baby.

In reality, the birth time is not that accurate simply because it is recorded only to the minute and not the second. In most deliveries, delivery of the head, the rest of the baby, clamping of the cord, and the baby's first breath all occur well within 60 seconds.

Also different hospitals will have different cultures assigning the responsibility to different nurses, so prioritizing the documentation of times may alter from place to place. And don't forget that the mechanism of birth varies depending on whether it is vaginal or by caesarean.

Hope this helps.
posted by commissioner12 at 6:41 PM on November 26, 2008 [4 favorites]

I was at a birth for work experience* (24 years ago - so it might have changed), and it was the moment the baby's entire head and body was out of the mother - as the doctor held the baby, he looked at the clock on the wall and said, time of birth 6:18pm. It wasn't very scientific, or accurate (the clock was a regular wall clock), but I guess there's no need for a great accuracy on that. Then they did the things like suctioning and weight and wrapping and the first cry came in the start of all that, and I think that was an indication of normal breathing, but that wasn't timed.
posted by b33j at 6:43 PM on November 26, 2008

Short answer: as soon as the whole baby comes out. Long, more accurate answer is provided by commissioner12 above.
posted by serazin at 8:16 PM on November 26, 2008

As soon as the whole body is out.
posted by tristeza at 8:25 PM on November 26, 2008

We use the computer clock in the room to call the time of birth. When I'm the delivery room RN, I look at the clock twice--once when the head delivers (in case there's a shoulder dystocia and I need to document how much time elapsed between the delivery of the head and the rest of the body), and then again when the entire body of the baby, down to the little pinky toenail, is all the way out. The latter is the official time of birth, to the minute. No one bothers to check the seconds.

In the OR, it's the same. When the baby is all the way out of the abdomen, that's the time of delivery.

How accurate is it? I guess that depends on how accurate the satellite time is on the computer.
posted by jesourie at 9:41 AM on November 27, 2008

I am an OBGYN. I have a vaguely recalled feeling (no undergrad or midwifery textbook handy to look it up!) that the technical definition of time of delivery is the moment when both shoulders are delivered (if it's head first), of when the head delivers (if it's breech). In practice it is as soon as the baby is clear of the mother's perineum, which is only a few seconds different. It is not the time of first breath, or the time of cutting the cord, because in certain circumstances that can happen before the body is delivered, or a long time afterwards.

For your statistical purposes the accuracy depends on what you are analysing. If you are focusing on "time of day" you need to know that the time is only recorded to the nearest whole minute, but if things are hectic, and nobody had time to check the clock, it might not be accurate to as little as one minute. If your analysis is focusing on the condition of the baby, then things are different, because the paediatrician actually starts a timer at delivery, and may record information to the nearest second.

The clocks used in my hospital vary from cheapo office wall clocks, to super accurate clocks timed off radio signals.
posted by roofus at 9:58 AM on November 27, 2008 [1 favorite]

I concur with all that. My second son was born two weeks ago, and it was pretty much - baby came out, midwife looked at the regular analogue clock on the wall and called the time from that.
posted by sycophant at 11:11 AM on November 27, 2008

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