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Pregnancy health centre

12 weeks pregnant

WebMD Medical Reference
Medically Reviewed by Dr Rob Hicks


How is your baby growing at 12 weeks?

The risky period for developing defects is now ending, which greatly reduces the chances of a miscarriage. The foetus will now be around 6cm from head to bottom (crown to rump). The facial features have become more human, with the eyes and ears migrating towards their final positions – the eyes had started on the side of the head and the ears a bit too low. The nasolacrimal groove that sits just over the upper lip will even be present.

Meanwhile, all the baby's organs are fully functional, with the liver now being able to make bile, the pancreas can make insulin and the kidneys can produce urine. The muscles in the digestive tract are able to contract. The skeleton and muscles are formed and fingernails will grow from the nail beds. At this stage the skeleton is made of cartilage – a type of firm but flexible tissue – but now it will start developing into hard bone. The genitals are also taking shape, though you still won't be able to tell the child's gender.

You won't feel your baby moving, but he or she will be kicking about and curling up his or her fingers and toes. This is because the baby's reflexes are getting some practise now that the rapidly multiplying nerve cells have formed connections in the brain. Because the vocal cords have formed, it's possible for the foetus to make sounds.

The placenta should be fully developed by now, taking over the tasks of transferring oxygen and blood from mother to baby, and the baby's waste back to the mother for disposal. It also takes over the production of hormones that were previously produced by the corpus luteum.

How are you changing in week 12?

Your waist will be thicker and a bump may start to become noticeable. Don't be surprised if the figures are going up on your bathroom scales. If a midwife does an examination, she may feel the fundus - the top of your womb - low in your abdomen.

Your metabolism has been changing, so you may find yourself feeling warmer. You may be having problems with headaches due to hormone changes and increased blood flow, and you may be feeling thirsty. However, as the first trimester comes to an end, you may also start feeling less tired.

What you need to know in week 12

Your gums may bleed more during pregnancy, so keep up good dental hygiene, flossing and brushing your teeth regularly, and ensure you visit your dentist at least once while you are pregnant.

If you have not done so already, ask your midwife about antenatal classes. These can get booked up early, so plan ahead and book now while spaces are available.

You might also want to start considering your birth plan. Your midwife can explain the options that will be available to you.

Next: 13 weeks pregnant

Additional pregnancy week by week pages:
14 weeks pregnant | 15 weeks pregnant 
16 weeks pregnant
| 17 weeks pregnant

Reviewed on January 16, 2017

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