Will it Be a Boy or a Girl?
Predicting and Influencing Gender

Can Timing of Intercourse Influence Gender Outcome?

At conception, gender is determined by chromosome characteristics - and it will be the male (or rather the male's sperm) that dictates whether the baby will be a boy or a girl.

Prior to conception, the unfertilized egg carries an X chromosome while the sperm can carry either an X or a Y chromosome. The gender of the baby comes down to one simple event:

• If the sperm carrying an X chromosome fertilizes the egg, a girl will be conceived.
• If the sperm carrying a Y chromosome fertilizes the egg, a boy will be conceived.

Timing Intercourse

Studies indicate that the sperm with the X chromosome - or female chromosome - have a longer life span than the male sperm (with the Y chromosome).

Yet the male sperm appear to have a higher motility. Sperm motility is measured in two ways: percentage of sperm exhibiting movement, and the quality - or dynamics - of this movement, which is called the forward progression. Poor motility means the sperm have a difficult time swimming toward the egg.

Hence, "female sperm" exhibit less motility - yet have a longer life span. The "male sperm" exhibit increased motility, but have a shorter life span than the X chromosome sperm.

It is believed that if intercourse takes place closer to ovulation, then the probability is greater that the child will be male, due to the high motility (forward progression) and the decreased life span of the sperm.

The sperm with the X chromosome - or female chromosome - have a longer life span than the male sperm, but exhibit decreased motility. Therefore, intercourse that takes place earlier may provide increased probability of a girl.

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Related Topics
Series On Shettles Method and Choosing Baby Gender
Part 1: Techniques of Gender Selection: Theories and Myths
Part 2: The Shettles Method: Timing Intercourse & Position
Part 3: Shettles Method: Fertility Charting and Gender Selection
> Chinese Gender Chart