Shettles method

Whelan method
What it is
Timed intercourse on specific days of your cycle.

Effectiveness
Whelan claims her technique is 68 percent effective for boys and 56 percent effective for girls, but many experts dispute this. Keep in mind that you always have a 50 percent chance of conceiving the sex you want.

How it's done
The Whelan method directly contradicts the Shettles method. The theory here is that biochemical changes that may favor boy-producing sperm occur earlier in a woman's cycle. So if you want a boy, you should have intercourse four to six days before your basal body temperature goes up. If you want a girl you should have sex two to three days before you ovulate.

Pros

• Requires no drugs or invasive medical procedures.

• Free or low cost.

• Safe.

Cons

• You must take your basal body temperature every day to figure out when you're ovulating, or use an ovulation prediction kit.

• There's no guarantee of success.

Availability
Anyone can try it at home.

For more information

• Learn more about charting your basal body temperature and ovulation predictor kits.

• Read Boy or Girl? by Elizabeth Whelan.