This is day 10 of your menstrual cycle

You may not mind whether you have a boy or a girl, but some theories claim you can influence the baby's sex.

270 days until your due date

Conceiving this week is all about timing, and some experts claim the timing of sex also affects the baby's sex.

Recent research suggests women who eat more calories (especially bananas) are slightly more likely to have a boy, while those who skip breakfast or eat fewer calories are more likely to have a girl. One theory is that the extra calories change vaginal secretions in a way that gives the Y sperm, which make boys, a boost.

Good to know

Making babies: Boys and girls

The Shettles method, devised by Dr. Landrum Shettles, is based on the idea that Y sperm (boys) are smaller, faster, and less hardy than X sperm (girls), and cope less well with an acidic vagina.

To conceive a boy, it advises:

Having sex as close to ovulation as possible, in positions that allow deep penetration, such as rear entry.
The woman having an orgasm, ideally at the same time as the man, to make the vagina less acidic.
Drinking a cup or two of strong coffee just before sex to give Y sperm an extra boost.

The Whelan method, devised by Dr. Elizabeth Whelan, says almost the opposite: sex four to six days before ovulation is more likely to produce a boy, and sex nearer ovulation a girl.

So what works? The mainstream medical view, backed by journals such as the New England Journal of Medicine, is that timing has little or no effect on the baby's sex. The possible exception is that sex two days before ovulation may slightly favor a girl.

Explainer

Glucose and boys

Research found that women with higher glucose levels, from eating normally and not skipping breakfast, were more likely to conceive a boy.

As a matter of fact

Same-sex siblings

If you already have two children of the same sex, you're 75 percent more likely to have another of that sex.

The baby's sex is random, but this pattern may be because some men produce better-quality X sperm (girls) or Y sperm (boys).

Couples with one child of each sex are statistically less likely to try for a third.

This is general information based on NHS guidance, not medical advice, and every pregnancy is different. Talk to your midwife or GP about anything that worries you. If your baby's movements slow down or change, or you have bleeding, severe pain or leaking fluid, call your maternity unit straight away. In an emergency, call 999.