Gender swaying

CONCEIVING A BOY OR GIRL?

From DIY gender swaying to pre-implantation genetically-screened designer babies, the science of how the gender of a baby is determined is multifactorial.

Each parent’s reproductive cells are encoded with DNA. The genetic information is called chromosomes and determines a child’s gender. Sex chromosomes come in two forms, an X chromosome or a Y chromosome. Women have two X chromosomes, while men have an X and a Y chromosome.

While you might think you have a 50% chance of having a boy and a 50% chance of having a girl, in reality, boy babies are slightly more common. A popular theory on this imbalance at the micro level is the physical weight of the X and Y chromosomes. Because Y has one less “leg”, it is lighter than X chromosomes. When a sperm carries a Y chromosome it may move more quickly than an X sperm, reaching the egg first. Some IVF clinics promote the idea that X sperm are bigger and don’t swim as quickly as Y sperm.

At a macro level, populations that are under stress will have a greater percentage of girls than boys and we know that at every life stage it’s the males who are more vulnerable. At conception there are more male than female embryos. Perhaps this is supporting the notion of Y spermatozoa being faster swimmers. The male's position is, however, immediately challenged. External maternal stress around the time of conception is associated with a reduction in the male-to-female sex ratio, suggesting that the male embryo is more vulnerable than the female. If it is a boy you are swaying for, a protective maternal environment along with the healthiest of sperm will enhance your desired outcome.

Gender swaying is an attempt to push that near 50/50 balance in the direction of your preferred gender.

Neither the Shettles Method nor the Whelan Method have been validated by science, and unhelpfully, present opposing ideas.

SHETTLES METHOD

In the 1960s, Dr. Shettles promoted the idea that sperm for X and Y chromosomes have different weights and move faster or slower than one another, that female sperm move more slowly but survive longer, while male sperm moves quickly but are more vulnerable. Consequently, Shettles recommended parents who want to conceive a girl should have sex up to a few days before ovulation, those hoping for a boy should wait until the day of ovulation. He thought that the secret to encouraging a particular gender at conception was all down to the male sperm.

WHELAN METHOD

In the late 70s, Whelan suggested that gender swaying could be possible as long as couples timed their intercourse well. Whelan theorized that the subtle and intricate biochemical changes in a woman’s body influenced X- or Y-carrying sperm’s journey to the egg- making the woman’s uterine environment the decider.

 Gender swaying for a girl with the Whelan Method recommended parents have sex 2-3 days before ovulation.

Gender swaying for a boy with the Whelan Method recommends having intercourse 4-5 days before ovulation. Because sperm can thrive and remain viable in the woman’s body for around 5 days, Whelan theorized that more male sperm would survive the waiting period between ejaculation and ovulation.

Researchers haven’t been able to verify either method as sound or accurate based on inconsistent results as shown by taking a gender prediction test.

SCIENTIFIC METHODS

Pre-implantation genetic screening, pre-implantation genetic diagnosis, and sperm sorting sway the outcome from 90%-100% for a boy and 73%-100% for a girl.

PGS and PGD for a boy -100%, sperm sorting -90%

PGS and PGD for  girls -100%, sperm sorting -73%

 Gender Swaying Diets

There are multiple ways parents have tried to influence a baby’s sex with their daily meals, including:

·       Calorie-Fat Gender Swaying Diet – This method comes from a research team that studied sex ratio change during war and famine. The theory is that during famine and war—when times are difficult and food may be scarce—women are more likely to conceive girls. But when food is plenty, women tend to conceive more boys.

According to this theory, eating a low-calorie diet increases the chance of a girl, while eating a diet high in calories increases the chance of a boy.

·       Mineral Gender Swaying Diet – The mineral diet specifically aims to help couples conceive a  girl through diet. The diet requires mums-to-be to eat foods that are low in sodium—that includes even forgoing adding salt to a dish—and high in calcium and magnesium.

·       pH Gender Swaying Diet – Much like the vagina, food has a pH. By eating highly acidic foods, this method asserts you can increase the chance of a girl. If you want to conceive a boy, this method advises you to eat foods with low acidity.

 Recent research

A  recent study has shed some light on what happens when a female egg meets the sperm and the results are in contrast to Shettles – the egg chooses the sperm!

If the egg likes the sperm, it sends chemical signals that tell it to swim faster. However, if the egg doesn't like the sperm, the signals it sends encourage the sperm to slow down.

Researchers from Stockholm University and the Manchester University NHS Foundation Trust found that the egg effectively chooses the sperm it wants, and rejects the others.

"Human eggs release chemicals called chemoattractants that attract sperm to unfertilised eggs. We wanted to know if eggs use these chemical signals to pick which sperm they attract. Once the sperm makes it up to the fallopian tube and meets the egg, it comes into contact with the chemoattractants in the follicular fluid”. said John Fitzpatrick, an Associate Professor at Stockholm University (1)

The researchers found it is likely the strongest sperm survives but mainly because the egg chose to have that happen.

(1) 10 June 2020 https://doi.org/10.1098/rspb.2020.0805

• Parents hoping to choose the gender of their baby in Australia will have to continue to go overseas to the US or Thailand, due to current restrictions around gender selection.

  Australia’s peak medical council chose not to legalise IVF gender selection in April 2017, with a decision by National Health and Medical Research Council that upheld an existing ban, all but for medical reasons, because the procedure could limit the “quality of life” of the child.

  "Sex selection techniques may not be used unless it is to reduce the risk of transmission of a genetic condition, disease or abnormality that would severely limit the quality of life of the person who would be born,” the guidelines state.

  Currently, only couples with medical reasons can choose the sex of their embryos when undergoing IVF.

  Sixty percent of couples who seek sex selection in the first world are looking for a girl.