So - 98 days left now, officially, and week 26 completed. The "40 week long pregnancy" is actually a myth, by the way. Due dates in America are currently calculated by "Naegle's Rule", which tells you to take the first day of your last normal menstrual period and add 7 days to it, then subtract 3 months and add a year. You end up with a calculation of 280 days, aka 40 weeks. The problem is, Dr. Naegle was, uh, wrong. A German doctor practicing in the 1850s, he determined that pregnancy would last ten lunar months (28 days times 10). Here's a quote from Birthsong Childhood Education and Support Services:
His calculation assumed pregnancy lasted around 280 days from the first day of the last menstrual period (or 266 days from ovulation - day 14). This very method is faulty on at least two points. One; his method was not based on any scientific fact, only his personal observations within his own practice. Two; few women have textbook cycles being 28 days long, with ovulation on day 14. A more recent and thorough study (Mittendorf 1990) found that pregnancy will last closer to 274 days. Reading further into this study also shows us that multiparas (women with one or more live births) and non-white mothers will have pregnancies lasting closer to 269 days. This shows us that Naegele's Rule establishes a due date that is a full 3-8 days shorter than what more recent and reliable studies show us to be more accurate.
What does this mean for pregnant women? One, it means that if you go around telling everyone your expected due date, be prepared for up to a week of people pestering you about "haven't you had that baby yet?" at the end. It's better to be a bit vague about it if you can. Two, as soon as you hit 40 weeks your doctor might start making noises about being "overdue" and wanting to induce. If there's no medical reason to consider induction - the baby is not distressed, there are no conditions of concern, etc, try to put this off as long as you can. You might not actually be overdue until 41 weeks and two days! I believe my midwife is allowed to let me go up to 42 weeks before she legally has to get things moving.
(There's actually a term in obstetrics - iatrogenic prematurity - which means "doctor-induced prematurity". Obviously sometimes there are good medical reasons to get that baby out of there, but many times, it's due to this 150-year-old flawed estimation process.)
I happen to know the date of my ovulation, and I also happen to know that it was Day 20 of my cycle rather than Day 14. This has been accounted for in my due date - I made sure of it, otherwise in first trimester the ultrasounds would have shown growth lagging nearly a week behind and I did not need that kind of unnecessary stress. Instead, every ultrasound has been met with comments about Fish being either "spot on" or "ahead" by a day or two for growth, which is a much nicer thing to hear.
Of course, as pregnancy progresses, the ultrasound estimate of due date gets less and less precise, and the window of error gets larger and larger. That's why the earliest ultrasounds are useful for dating the pregnancy.
But really, if there are no problems, why not just let the baby come out when it's ready? Part of me feels that way. And then another part of me thinks of my friends in the loss group where everything was fine until one day in the 39th or 40th week when things suddenly fell apart with no warning at all and their baby died...and that part of me says "yes please, get it out sooner rather than later!"
The internal discussion is ongoing and unresolvable, and I am hoping that Fish makes the decision for me at a reasonable time, and arrives happily and healthily.
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