THERE WERE A LOT of kids at our housewarming party -babies, toddlers, even one or two who were big enough to pointedly inform their parents how bored they were. The last time we moved, seven years ago, there hadn't been any. So here we are, I thought, almost 40, and really it hasn't turned out so badly for a lot of the women I know: we've got nice husbands -maybe not the first man we married, but everyone makes mistakes - work that interests us and (except for the writers among us) pays a grown-up living, and adorable healthy children we love to bits.

I don't mean to say that our numbers have all turned up in the Grand Happiness Lottery - who knows what even your best friend is thinking at 4 in the morning? - but no one's drinking or drugging or sunk in a sour mist of frustration and rage, and no one's sanity is fraying around the edges, as happened to some of the women on the block where I grew up. There's another thing we have in common: no one had a baby before she was ready, wild to be a mother. And birth control being what it is, that means that many of the women in our living room that day had had abortions.

It's a measure of the changing national climate where abortion is concerned that I feel uneasy about writing this for publication. The so-called right-to-lifers have not yet scored a direct hit against abortion, unless you count clinic bombings, which I do. But they've done something that may in the long run have an even more serious effect: they've set the terms of the debate. Have you noticed? It's not about women's bodies anymore, or family planning, or sexual freedom. It's about women's ''convenience,'' to use the pro-life buzzword, versus babies' lives. Framed like that, the abortion debate can turn out only one way. If the fetus is a person, how can its life be less important than a woman's liberty and pursuit of happiness?

Faced with the tremendously emotion-laden image of the vulnerable, innocent preborn baby, defenders of legal abortion tend to respond with another set of emotional images: pregnant schoolgirls, rape and incest victims, those who die in pregnancy or childbirth or give birth to infants with horrendous, fatal conditions like Tay-Sachs disease or AIDS. The images are real, all right - I know a woman who got pregnant from a date rape, and another with a heart condition that could have killed her had she been forced to carry a child to term. But look how much ground they concede. What if it's not your life that's at stake but ''just'' your health? Or your diploma? Or your job? Or your marriage? What if you weren't forced to have sex, and you're not 15, but 25 - or 35?