The two sex chromosomes in the egg and sperm are what determine whether you'll have a boy or girl. Eggs always have an X chromosome, and sperm have either an X or Y chromosome. Whichever sperm is the winner will penetrate and fertilize the egg, creating either an XX (girl) or XY (boy) pair.
It's all about Dad's genes
A man's X and a woman's X combine to become a girl, and a man's Y combines with a woman's X to become a boy. But if the sperm don't have equal Xs and Ys, or if other genetic factors are at play, it can affect the sex ratio.
According to those who follow the Shettles method, you can up your chances for a girl by aiming to have sex two to four days before ovulation. The theory is that “girl sperm” are stronger and swim slower than “boy sperm,” so they are more likely to survive the wait for the egg to arrive.
Nature is designed to favour the conception of boys from September to November and girls from March to May because of an evolutionary mechanism aimed at keeping the overall sex ratio as near to 50:50 as possible, the scientists said.
Aged 19 to 26: 50% chance in any one menstrual cycle. Aged 27 to 34: 40% chance in any one menstrual cycle. Aged 35 to 39: less than 30% chance in any one menstrual cycle, but with a male partner five years older, the chance falls to less than 20% chance in any one menstrual cycle.
No, you can't influence the sex of your baby. Most studies show that males produce and release sperm fairly evenly, as in a 1:1 ratio of X chromosomes and Y chromosomes. This means that the chances of having a girl vs. a boy will be about 50:50.
The scientists also note that at the age of 35, the proportion of sperm carrying an X chromosome also seems to increase, meaning older dads are more likely to have daughters. In human reproduction, the Y chromosome is responsible for making a male child.
However, a 2018 Gallup poll found that 54% of Americans said boys were easier to raise than girls, while only 27% said girls were easier, and 14% said there was no difference. Some research suggests girls are better communicators in the younger years, but this may change later on.
While historically, there have been about 105 boys born for every 100 girls worldwide — which creates a “sex ratio at birth” of 1.05 — the share of boy babies has increased in recent decades.
Among 132 families that had three children of the same sex, 69 went on to have another child of that sex, and 63 went on to have a child of the opposite sex. The chance of having a girl after two boys was about 48 per cent and the chances of having a boy after two girls was slightly lower, at only 46 per cent.
In a survey of more than 500 parents by financial resource site MoneyTips released exclusively to MarketWatch, parents say it's the girls that cost you more. They estimate it costs, on average, an additional $2,160 a year to raise a daughter versus a son through age 18.
Sons are easier to raise, daughters not so much
According to Parents, gender matters when it is about raising children. Mothers have found girls to require a lot of emotional handling even from infancy. But boys are more easy-going and emotionally stable.
However, a 2018 Gallup poll found that 54% of Americans said boys were easier to raise than girls, while only 27% said girls were easier, and 14% said there was no difference.
Females influence the gender of their offspring so they inherit either their mother's or grandfather's qualities. 'High-quality' females – those which produce more offspring – are more likely to have daughters. Weaker females, whose own fathers were stronger and more successful, produce more sons.
Men inherit a tendency to have more sons or more daughters from their parents. This means that a man with many brothers is more likely to have sons, while a man with many sisters is more likely to have daughters.
As men age, their risk of fathering a child with Down syndrome may increase—the older the man, the more likely that the process of spermatogenesis, or sperm production will go awry, leading to sperm that contain errors like an extra chromosome.
Sex selection in IVF is not legally allowed in Australia for reasons of family balancing.
Vitamins to conceive a girl
The study that looked at diet also had participants take magnesium, calcium and Vitamin D supplements in addition to their prenatal vitamins. The study reported that the women who took these supplements — in addition to their diet and timing of sex — gave birth to baby girls.
Nature is designed to favour the conception of boys from September to November and girls from March to May because of an evolutionary mechanism aimed at keeping the overall sex ratio as near to 50:50 as possible, the scientists said.
Peak male fertility is around 25-29 years old. Sperm quality begins to decline at 30. At 45, men begin to experience a significant decrease in semen volume. Older men can also take longer to conceive a child.
Geriatric pregnancy is a rarely used term for having a baby when you're 35 or older. Rest assured, most healthy women who get pregnant after age 35 and even into their 40s have healthy babies.
The pull-out method is about 80% effective. About one in five people who rely on the pull-out method for birth control become pregnant.