Thursday, March 22, 2007


Here's another uninspired -- or at least unfocused -- post.

First, knitting. I am taking comfort in the number of other knitters who seem to be in a bit of a funk. I decided to circumvent my gauge problems by starting a Baby Surprise Jacket. Elizabeth Zimmerman is so encouraging and laid back about knitting. Her writing sooths and inspires.

Six months ago or so I picked up her Knitting Almanac so I could have the BSJ pattern. Then I found a site that translates it into a row by row accounting that I find easier to follow. I am using those directions, but keeping the Almanac close at hand for company and reassurance. I mean, look at her:

Any knitting problem is a little easier to face with her wry face and handwritten message of good will just below.

So this is the start of the jacket. In cream yarn my MIL gave me, leftover from a sweater she knit my younger son. And for contrast, some sock yarn that refuses to gauge up for my first attempt at socks.

I don't know that the wool (cream) and bamboo (varigated) will combine for a particularly harmonious final product. But what the hell.

Second, birth. I thought I'd come to peace with the whole disconnect between obstetrical calendar keeping and the rest of the world when I was going through my own pregnancies. But it has started bothering me again.

Most mothers know, or with a little prompting remember, that pregnancies -- and, therefore, fetal age -- are dated from the first day of the last menstrual period. You may also recall that ovulation typically occurs two weeks before blood flow starts.

For the average woman who ovulates mid-cycle (i.e. halfway between the start of two periods) this means [preachin' to the choir here, I know] that two weeks of "gestation" have elapsed before conception can even occur. You are "four weeks" pregnant when you notice you're late for your period.

The reason for using the last menstrual period (LMP) date as a peg for calculating the due date is because it is more certain than ovulation. Women KNOW when their period starts. Many do not know when they ovulate.

BUT, many of us KNOW when we conceived. How many times have you heard stories about "the one time we had sex that month" or "I decided to leave my diaphragm out that weekend?" And that date is not exactly two weeks after our LMP. Yet here we are pregnant.

Those of us still must conform to the LMP dating system, even though we know better than it, when our babies were conceived.

I guess I find it both an artificial construction and, often, a denial of our own knowledge of our bodies to use LMP as the pregnancy dating system. Why not work with women to see if a conception date can be approximated based on their personal reproductive and recent sexual history. Then, if not, if LMP must be used, then just subtract two weeks from the total so that two weeks after conception is week 2, not week 4.

And lest we think it's crucial to know exact gestation age, remember that plenty of pregnant women have NO idea when their last period was. Maybe they are nursing and haven't bled in two years. Or they just don't track their periods and can't remember if they last bled 3 weeks ago or eight. Those women still manage to have healthy babies and survive at least some part of their pregnancy without a firm due date. (I know, I know, now they do repeated ultrasounds to estimate fetal age in those cases.)

I don't think I'm going anywhere with this other than to say let's count pregnancy from conception and consider a baby "at term" 36-40 weeks later.

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Blogger Tara said...

The whole calculation of due date/gestational age bothers me too, especially the way many care providers ignore (or treat with skepticism) a woman's knowledge of her own body and cycle. What fraction of women have 28 day cycles *and* ovulate on day 14 every time? Not I.

As a side note though, I have learned from personal experience that when you had sex is not always the same as when you ovulated/conceived... some sperm are very hardy LOL! So of course there is never going to be a perfect way to calculate when baby will come, but there could be so much more respect built into the process.

2:54 PM  
Anonymous Anonymous said...

I am bothered by the idea that women can't possibly know when we conceived, mostly because it's just a form of thinking women can't hold numbers in their pretty little heads. However, I like the concept of counting pregnancy from last menstrual period rather than conception because it counts the preparation time of building up the uterine lining as an integral part of pregnancy. It helps me to think about the woman's pregnancy and the fetus' age as distinct, yet connected things.

8:32 PM  
Blogger Chris said...

It's Chris from Briar Rose! thanks for the tip about getting to the Yarn Harlot venue early (are you going?) I actually thought I would get there an hour early....Can I get a mocha there? My very favorite thing in life aside from knitting and dyeing........The EZ Baby Surprize Sweater!!! yay!!! I have a new Grandbaby on the way (you are sworn to secrecy, since Christy hasn't announced it to the world yet).........great idea! EZ's sweater.....yeah....

4:39 PM  
Blogger cooler*doula said...

Oh God yes. This has bothered me too. I knew exactly when conception occurred, but LMP? Beat the crap out of me.

I remember talking to the husband of an expecting friend when she was "overdue" and reminding him gently that the way the due date was calculated was rather, well, arbitrary.

He replied that he had been stunned to learn how it was calculated. Rather like randomly throwing a dart, he remarked. (His wife had not had regular periods for years, so LMP was a particularly foreign concept for them...)

8:20 PM  
Blogger doulicia said...


Congratulations on the gestating grandbaby. Keep us posted.

As to a latte, there's a machine dispenser. You'd be better to grab one from Sweetwater's or another Main Street store and walk the two blocks to the library. I'm not going; I went last spring and loved it. But having seen her once, and knowing how popular she is, I'd rather leave an empty seat for someone who couldn't see her last time.

10:08 AM  
Blogger The Mommy Blawger said...

I kind of like the poetry of "forty weeks".

But I can't tell you how irritated I am when I hear stories of women who take their temp & mucous charts into their OBs, who completely ignore them in favor of the LMP date. The idiocy!

1:07 AM  
Blogger Deanna said...

I charted my cycles to avoid, then achieve, pregnancy. I never ovulated before day 25, would show my charts to my midwife's assistants, yet they gave me an EDD that was at least 3-4 weeks off. With my second and third babies I learned from my mistakes -- I just lied and told them my last menstrual cycle was 13 days prior to my ovulation date. I was often more accurate than they were!

Love the BSJ, I'm looking for the pattern myself. My baby (now 1 year old) needs one. ;)

7:40 PM  

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