2πr

Yesterday we had an ultrasound because at our previous visit the midwife was concerned that I was measuring small. It turns out our baby girl is just fine - 5.5 or 6 pounds right now, at 34+ weeks. She's also head-down (as we suspected) and facing my back, in perfect position for birth.

Meanwhile, I routinely wake up around 4 or 4:30 in the morning for no apparent reason. I am usually relatively comfortable in my bloated body (except for the occasional hip pain from lying stagnantly on one side all night). The baby may be lightly kicking, or not. I may or may not have to pee. I just wake up. My brain wakes up, too. Sometimes it ponders how we will ever pick a middle name. Sometimes it tracks to work and everything I have left to do before starting maternity leave.

So early this morning, while attempting to quiet my brain and fall back asleep, my brain rebelliously turned to musing that I'd learned during the ultrasound that the baby's head is about 31 cm in circumference. Since Jr. High geometry class, I don't think I've ever actually needed to use this particular formula, but at about 4:34 AM, my brain was suddenly dividing 31 by approximately 6.28. And then doubling that (my foggy brain didn't realize I could just divide by pi instead of dividing and then multiplying to find the diameter).

The answer is dangerously close to 10 cm. About which my brain immediately asked me, "Isn't that the max dilation of the cervix? Does her skull continue to grow for the next six weeks?"

Needless to say, this did not help me fall right back to sleep. I did sleep, eventually. I trust that my body will figure this all out.

[And yes, I realize the baby's skull is soft and it smooshes into a cone-head for the actual delivery. This math was just a little startling!]