You probably already know that having sex just before ovulation is the recommended way to get pregnant. Since sperm live two to five days inside the woman's system, and eggs are only viable for 12 to 24 hours after ovulation, it is usually best to have the sperm right there waiting as the egg drops.
There are two types of sperm, male and female. The male sperm have an X chromosome and Y chromosome (which is actually a broken X without a tail – go girls!). Female sperm contain a double X, which is slightly heavier. Thus, the male sperm swim faster.
Think of sprinters versus marathon runners.
The boy sprinters get right up to the ovaries and hang out in the fallopian tubes waiting for the egg to drop. This sprint to the egg uses up all their energy, so if they aren't able to quickly fertilize an egg, they die. The female sperm (our marathon runners) keep a slow and steady pace, reserving fuel as they make their way to the ovary.
So, for a probable boy baby, intercourse should occur the day you ovulate. If you have sex a few days before you ovulate (and then not again), the boy sperm will have died by the time your egg appears, leaving room for the girls to get to work.
Of course, many factors complicate this issue, including maternal age and health of mother and father. Hardest of all is knowing the exact moment you ovulate. But, if you really have your heart set on one gender over another, this approach is worth a try.
Feel free to share this blog and my website with your friends. I love to help people have babies.
Yours in good health,
Rachel Blunk, L.Ac.
Rachel Blunk is a fellow of the American Board of Oriental Reproductive Medicine who has specialized in fertility since 2002. Her practice is located in Fort Collins, Colorado. See more at www.BabyByBlunk.com.