We sit around a glass coffee table. The room is clean and modern, the furnishings are that chicken soup colour favoured by architects — and expensive private clinics. Which is just where they are heading. The Gunns want a baby girl. The couple seem slightly bemused. Not so much because they are travelling halfway round the world for a fantastically expensive and invasive treatment.
No more disappointments: Choose the sex of your child | Society | The Guardian
It is also unlikely you will find out the sex with an NHS scan at 16 weeks, as generally, the only scans you are given in the first and second trimester is the week dating scan, where telling the sex is not possible, and the 20 week anomaly scan. Some private scanning places have deals which often include 4D peeks, teddy bears and photos, and even a little video of your bub moving around. And, if you want to make the sex a surprise, you can always ask the sonographer to keep it private, and write it down in an envelope for you so that you can have a reveal later on, with both private and NHS scans. Though most places will not perform a gender scan on you until 16 weeks, sometimes you can see what you are having sooner. If the baby is in the correct position — with their legs open with a clear view from underneath — it may be obvious to the sonographer as early as 14 weeks, as by then the differentiation of male and female sex characteristics are complete. However, to tell the sex accurately, it is best to wait until between 16 to 20 weeks.
If a pregnant woman has a neat bump that sticks out in front like a netball, then it is a boy. If the weight is more spread out around her middle then it is a girl. Or so they say. As any mother will tell you, there is no shortage of family members and friends offering folk stories about how to tell the sex of your baby during pregnancy.
Medical researchers at Melbourne's Murdoch Children's Research Institute have made a new discovery about how a baby's sex is determined -- it's not just about the X-Y chromosomes, but involves a 'regulator' that increases or decreases the activity of genes which decide if we become male or female. An embryo with two X chromosomes will become a girl, while an embryo with an X-Y combination results in a boy," Ms Croft said. High levels of the SOX9 gene are needed for normal testis development.