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Weeks 12-16

pregnancy adviceWelcome to start of the second trimester!

There are a few ways to count trimesters, based on either gestation, development or conception, we love THIS calculator if you’re not sure where to start.

Your baby is the size of a fig. Weighing in at around 4.9 ounces and 2.1″ long.


The biological sex of the foetus can now be seen by looking at external sex organs on an ultrasound. If using the nub theory; ultrasounds dating between 12 to 14 weeks are optimum. If you’re planning on having a gender scan, we recommend waiting until week 15, as female nubs can still protrude before this point, being confused for penises in a potty shot.

If your baby is a male, his prostate gland begins to develop.

If your baby is a female, her ovaries move down from the abdomen to the pelvic area. Hundreds of thousands of eggs form in the ovaries over the next couple of weeks.

You will have your dating scan this month, where your sonographer will measure your baby to tell you the exact gestation of your baby. They will also be looking to see if your baby is growing in the right place, if you’re having more than one baby and if they can see any abnormalities, such as spinabifida. You will be offered the screening for Down’s Syndrome, as well as other conditions, which is called the ‘combination test’. It involves a blood test and measuring the fluid at the back of the baby’s neck (nuchal translucency).

If you want to know your baby’s gender, The Nub Theory is also applicable from the 12th week, and nubs can be seen during your scan. If you’re lucky, you may have the nub imaged in a photograph for you to take home. If you do, our Nubologists can take a look and predict your baby’s gender, with up to 95% accuracy. You can read more about The Nub Theory by following the links above.

Also during this month, your baby’s hair begins to grow and the roof of the mouth is formed.

Some of the troublesome early signs and symptoms of pregnancy tend to go away when you’re into your second trimester, and for lots of women, pregnancy and nausea usually lessens, but other digestive problems like heartburn may continue.