Monday, November 06, 2006


The "science" of predicting gender

I've been spending an inordinate amount of brain power lately speculating on whether this little baby of mine is a girl or a boy. I know I'm not supposed to have any preference, and I'm probably going to have to go back and do a lot of revising of this blog one day so the boys I do have don't think I only kept them around because I was holding out for a girl, and I certainly don't want a potential future boy to think he was unwanted.

But, let's face it - I really do want a girl. *cringe* (That cringe is partly because I feel bad stating it so baldly, and partly because I feel like I'm tempting fate. Knock some wood for me, wouldja please?)

There's lots of reasons I want a girl. I want a girl because I think it would be an easier family dymanic to have two boys and a girl rather than strand Simon in the middle of three boys. I want a girl because I was a girl, and I've always had such a wonderful relationship with my mother, and she with her mother before that, and I would love to carry that on to the next generation. I want a girl because when boys grow up, they tend to move away and girls stay close. I want a girl simply because I don't have one.

Another day, I'll blog about why I want another boy. Because I do. Ambivalence, thy name is Dani.

I've heard a lot of women say they just 'knew' what the baby's gender is. So far, I'm two for two - I was convinced in my heart of hearts both Tristan and Simon were girls, right up until they exposed themselves on the ultrasound. (Exhibitionists they both are to this day.) This time, I can admit an absolute lack of insight - I have no inkling whatsoever.

The waiting, it is making me a little squirrelly. Four more weeks to the day - not that I'm counting - and we'll hopefully have some resolution to this mystery. What I will do with a result like "well, it's about 60% likely that it's a ..." remains to be seen.

In the interim, I've succumbed to folklore to tickle my fancy. I came across an article in the Canadian Medical Association Journal, where they set about to disprove three common "old wives' tales" for predicting gender. Sad though it is, I was more than happy to run through them all to see if I could glean any inside information.

The three tests they examined are the fetal heart rate test, the Chinese calendar test and the Draino (!) test.

The fetal heart rate test implies that babies with heart rates greater than 140 bpm were girls, and heart rates slower than than were boys.

Check! Baby's heart rate at the last ultrasound was 169 bpm. Girl.

The ancient Chinese birth gender chart, "buried in a tomb near Beijing for 700 years", apparently predicts gender with "over 90% accurracy" based on the month of conception and the mother's age at conception.

Check! Conceived in August, when I was 37 years old. Girl.

The third test involves peeing on some Draino, and even I, the queen of impatience, am not willing to risk a chemical burn to my nether regions to try this particular test. Call me crazy. We'll leave a question mark beside that one and call it a day.

And in case you are wondering, yes, it was always in the back of my mind that the whole predicate of the article in the CMAJ is the fact that the tests did NOT have any statistically significant value in predicting gender. I know, I know.

So anyway, I was willing to fold this up and keep it in my mental hope chest as a good omen when it occurred to me that I have my own control group to work with. I ran through both tests again given the same information I had for Tristan and Simon and the results, although somewhat deflating, are hardly surprising.

Turns out Tristan and Simon are both girls, too.