How do we give the girl sperms a major edge over the boys? Men have little control over the proportion of female to male sperms they produce. They just produce a mix of about equal numbers of each. So, it’s up to the woman to take control.
Sperm must swim through the uterus to have any chance at reaching the egg and fertilizing it. Fortunately, or unfortunately, depending on one’s viewpoint, the uterus isn’t a neutral environment in which all sperms are treated equally. Depending on the woman’s diet, her vagina’s pH may be acidic or alkaline. An acidic follicular fluid favors female sperm by rendering male sperms weak and directionless. How may a woman cause the pH of her follicular fluid to be acidic?
Eating a diet higher in magnesium, calcium, and acidic foods such as corn, meat, beans, fish, plums, coffee, eggs, liver, and yoghurt and avoiding alkaline foods such as bananas, oranges, potatoes and watermelon create an acidic environment. Supplements such as calcium, folic acid, magnesium, and vitamin C help make the cervical mucus acidic.
Men can help by keeping his genitals warm because heat destroys male sperms faster than females.
According to The Shettles Theory, boy sperm travels faster and have a shorter life span. Having sex two or three days prior to ovulation pretty much guarantees few male sperms will still be alive to do the deed.
The depth of penetration during intercourse affects where the sperm will be deposited in the vagina. Shallow penetration leaves the sperm near the acidic entrance to the vagina where deeper penetration favors male sperm.
While none of these approaches have been proven to work and would never guarantee a girl, they could help. Regardless, testing them could be quite enjoyable.