My lovely surrogate sister S___ has given birth twice before. I've seen both her children very soon after they were born. In fact, the first time K___ and S___ met, it was the day after S___ had given birth to her first child, so it was a bit of a case of, 'this is my friend S___, and my god - that must be her breast attached to that baby... How unexpected!'
K___' sister has two kids and she has rather more mates who've dropped sprogs, so knowing people who've given birth is hardly new to either of us. Without taking anything away from the kids that have already been born, those that our friends are going to drop now, have assumed a greater interest for us - I hope no one would object to me saying that.
My friend B___ is now two days over her due date. When K___ and I disappeared off to Cornwall for a few days, I made sure that I emailed them and said that we hoped that if we missed it, everything went well and we'd look forward to hearing from them. When we got back, there was an email from B____ saying they'd seen their midwife and she had told them the baby's head was 2/5 engaged. They've been given a date of the 21st, roughly two weeks later as an induction date.
S___, we have learned, is something of a legend in our town. We mentioned a friend of ours who'd gone weeks and days over her due date to D_____, the midwife and she immediately said, 'Oh, you don't mean S___ E___ do you?' Apparently, she's gone the longest that anyone knows of before going on to have a normal, natural birth. She's pregnant with her third now, so we'll see if she can beat her record. I'm sure that if it comes to it, she'll resist induction for as long as possible. If she really crosses her legs hard and tries not to think about it, her third and our first might be born at about the same time! Well, not really, but you know...
This all makes me think about due dates. In 1850, a chap called Dr Naegle determined that the average length of gestation was 266 days from conception. On the assumption that the average woman has a 28 day menstrual cycle and ovulates on day 14, he determined a very simple formula to determine due date.
((Last Menstrual Period + 7 days) - 3 months) = Due Date
Obviously this doesn't take account of the years - you're assumed to be clever enough to work that out for yourself. Even a chimp knows that many women don't have 28 day periods and that even if they do, there's no guarantee they ovulate on the 14th day, so that already puts some strain on the old formula. There are a whole host of other factors that can affect the date; ethnicity, the number of previous successful pregnancies, the degree of prenatal care available, the general health of the mother to be, whether the father was a Klingon and a few other factors. Despite the fact that there's clearly a bit of an issue of trust over Dr N's formula, this is still the one used today.
Apparently, for a first-time Caucasian mother - i.e. K___, you can realistically add 15 days to the Naegle date, making a total of 288 instead of 266. For a subsequent birth to a Caucasian mum, it's 10 days. Black and Asian women have slightly shorter gestation times - about the same as the Naegle date, as it happens. However, in numerous places I've seen it said that you can take two weeks either side of the due date as a realistic birth window.
For us, this means that if we do add those 15 days, our new ETA is 22nd January, with a window from 8th Jan (the day after we'd originally thought our due date was) to 7th of Feb, but for my money, there's too many variables to try and pretend we really know what's going on. It's going to be simpler to stick with the Naegle one, even though it probably is wrong.
However, it just shows you something about induced pregnancies - if they're offering them two weeks after the Naegle due date, there's evidence to suggest that the mother is only then reaching her natural due date. According to some US figures (I think; they're not referenced properly) only 4% of babies are born on their due date, though about 76-90% of babies are born in the two week period either side of the due date. 6-10% are early, before 37 weeks and 4-14% can last more than 42 weeks and if that's the case, the S___ was the most sensible person for refusing to let them induce earlier.
All this probably explains why K___ said to me this evening that she wasn't going to be induced if she could help it!
K___' sister has two kids and she has rather more mates who've dropped sprogs, so knowing people who've given birth is hardly new to either of us. Without taking anything away from the kids that have already been born, those that our friends are going to drop now, have assumed a greater interest for us - I hope no one would object to me saying that.
My friend B___ is now two days over her due date. When K___ and I disappeared off to Cornwall for a few days, I made sure that I emailed them and said that we hoped that if we missed it, everything went well and we'd look forward to hearing from them. When we got back, there was an email from B____ saying they'd seen their midwife and she had told them the baby's head was 2/5 engaged. They've been given a date of the 21st, roughly two weeks later as an induction date.
S___, we have learned, is something of a legend in our town. We mentioned a friend of ours who'd gone weeks and days over her due date to D_____, the midwife and she immediately said, 'Oh, you don't mean S___ E___ do you?' Apparently, she's gone the longest that anyone knows of before going on to have a normal, natural birth. She's pregnant with her third now, so we'll see if she can beat her record. I'm sure that if it comes to it, she'll resist induction for as long as possible. If she really crosses her legs hard and tries not to think about it, her third and our first might be born at about the same time! Well, not really, but you know...
This all makes me think about due dates. In 1850, a chap called Dr Naegle determined that the average length of gestation was 266 days from conception. On the assumption that the average woman has a 28 day menstrual cycle and ovulates on day 14, he determined a very simple formula to determine due date.
((Last Menstrual Period + 7 days) - 3 months) = Due Date
Obviously this doesn't take account of the years - you're assumed to be clever enough to work that out for yourself. Even a chimp knows that many women don't have 28 day periods and that even if they do, there's no guarantee they ovulate on the 14th day, so that already puts some strain on the old formula. There are a whole host of other factors that can affect the date; ethnicity, the number of previous successful pregnancies, the degree of prenatal care available, the general health of the mother to be, whether the father was a Klingon and a few other factors. Despite the fact that there's clearly a bit of an issue of trust over Dr N's formula, this is still the one used today.
Apparently, for a first-time Caucasian mother - i.e. K___, you can realistically add 15 days to the Naegle date, making a total of 288 instead of 266. For a subsequent birth to a Caucasian mum, it's 10 days. Black and Asian women have slightly shorter gestation times - about the same as the Naegle date, as it happens. However, in numerous places I've seen it said that you can take two weeks either side of the due date as a realistic birth window.
For us, this means that if we do add those 15 days, our new ETA is 22nd January, with a window from 8th Jan (the day after we'd originally thought our due date was) to 7th of Feb, but for my money, there's too many variables to try and pretend we really know what's going on. It's going to be simpler to stick with the Naegle one, even though it probably is wrong.
However, it just shows you something about induced pregnancies - if they're offering them two weeks after the Naegle due date, there's evidence to suggest that the mother is only then reaching her natural due date. According to some US figures (I think; they're not referenced properly) only 4% of babies are born on their due date, though about 76-90% of babies are born in the two week period either side of the due date. 6-10% are early, before 37 weeks and 4-14% can last more than 42 weeks and if that's the case, the S___ was the most sensible person for refusing to let them induce earlier.
All this probably explains why K___ said to me this evening that she wasn't going to be induced if she could help it!
We've been given due dates that span a week, even though I presume everyone's using the same little spinning wheel to figure it out. We're now past most of those, but my mother has always emphasized that a due date is just an estimate, not a target, and that (as you said), if you're within two weeks of it, you're due.
ReplyDeletePersonally, I wish that they wouldn't hand them out, although expectant parents probably wouldn't stand for that. I'm honestly quite tired of being asked when he's due. . .by the same people. . .every day. The same people who then tell me their favorite story about someone who was early, late, sideways, etc.. . .also every day.
I'm really done trying to act interested in these stories, and I'm seriously considering tattooing the due date on each of their foreheads so they never ask again.