The Right Way to Get Pregnant

By William Grigg

You will have a problem, however, knowing when you're five days away from ovulation. There is no test to pinpoint that. A further problem: Your ovulation and fertile "window" – the time when you're likely to get pregnant – can wander around. It's like a moving target.

Older guidelines for getting pregnant assumed that the average woman is fertile between days 10 and 17 of her menstrual cycle, but that's a very rough approximation – an "average" that may not mean much for you as an individual woman. In an NIEHS study, 17 percent of the women were fertile by day seven of their cycle. Two percent of women were fertile by day four! Our study also showed very late ovulations occur, even in women who said their cycles were usually regular. Because of these late ovulations, 4 to 6 percent of the women were potentially fertile more than 28 days after the start of their cycle. In fact, even women who regarded their cycles as "regular" had a 1 to 6 percent probability of being fertile on the day their next period was expected.

Q: If ovulation times vary widely - and you can't accurately predict them five days ahead of time –what should a healthy young woman do? How, in other words, should you go about trying to get pregnant?

A: Well, the director of our NIEHS study, Dr. Allen Wilcox, suggests many couples are best off forgetting about getting the timing "right."

"If the average healthy couple wants to get pregnant, they are just as well off to relax and forget 'fertile windows,' and simply engage in unprotected intercourse at least two or three times over the course of each week," Dr. Wilcox says.

That's easy-to-follow advice, and you're likely to hit "right" two or more times within the fertile days occurring in each of your cycles.

Want to see more?

• Safeguard Your Fertility: 6 Simple Steps
• Too Toxic to Conceive: Is Your Lifestyle to Blame?
• Private Suffering: The Issue of DES Daughters
• Talk about it!