Wednesday, February 8, 2012

Birthweights

Babies have been born lately.

This makes me think back to my own children's births.

They say that a baby gains 1/2 lb. (or 8 oz.) per week in the last month of pregnancy.

If that is true, all my children were on track to be 9 lbs.

I am thankful that they were all early.

Shannon was due on November 6, but she was born on October 23. That made her exactly 2 weeks (14 days) early. If she had been born two weeks later and gained 8 oz. per week, she would have added exactly 1 lb. to her birthweight, which was 8 lbs. and 0.5 oz. She would have weighed 9 lbs. and 0.5 oz. on her due date.

David was due on June 20 but was born on May 22. That made him 29 days early. Divide 29 days by 7, and you come up with 4 weeks and 1 day early. The four weeks would have added 2 lbs to his birthweight, the extra day would have added a hair more than an extra oz. ...David's birthweight was 7 lbs. 2 oz. but had he stayed in the oven until his due date, he would have weighed 9 lbs. 3 oz.

Laura, like Shannon, was due on November 6, but she came on October 8. Like David, she was 29 days early, so as we did for David, we would add 2 lb. and 1 oz. to her birthweight to determine what she would have weighed on her due date. Her birthweight was 7 lbs. and 0.5 oz. So she would have been 9 lbs. 1.5 oz. on November 6.

Jonathan was due on September 6, but he was born on August 27. He was 10 days early (it felt pretty late to me! ...although I always thought he was 9 days early until I actually figured it out on the calendar today). Using the formula above (babies gain 8 oz. per week the last month in the womb), we can do math: 8 oz. per week equals 8 oz. per 7 days, which if you plug it into a calculator equals 1.14 oz. per day. Over ten days, that comes to another 11.4 oz. that Jon would have packed on in addition to his birthweight, which was 8 lbs. 6 oz. Addition gives us 8 lbs. 17.4 oz. which is really 9 lbs. 1.4 oz. Bingo. Right in the pocket.

I think this is pretty interesting, even though probably nobody else in the world would.

And I think it bears repeating: I am thankful that they were all early.

1 comment:

Shawn said...

Wow, all within a couple of ounces on the due date. That is pretty remarkable. Glad they came early; I don't think a full term delivery would have been easy...