15/05/2012 07:12 BST | Updated 22/05/2015 06:12 BST

Pregnancy Week By Week: Week 12

week 12: scans PA

Welcome to week 12

It's a milestone week for most expectant mums. It's the week many expectant parents get their first glimpse of their unborn baby during an ultrasound dating scan. After 12 weeks the risk of miscarriage rapidly drops, so many women choose to announce their pregnancy to friends, family and at work at this time. Week 12 also brings your first trimester to a close: one third down, two to go.

Inside story

Your baby is now around 7cm long (that's about two-and-a-half inches) and weighs around 14g (just over half an ounce). Your baby's face looks a lot more human now as the eyes are properly aligned rather than being on either side of the head, and the chin is more pronounced. All the organs are doing their job: the liver is producing bile, the kidneys are producing urine and the brain is developing fast.

On the outside

This week your placenta takes over the job of producing hormones and your uterus lifts up a bit from behind your pelvic bone. This could mean there's a little bump to show off to friends and family. Lots of women say they really start to feel pregnant from this week: partly because the greatest danger of miscarriage has passed and they relax into it a bit more; the beginnings of a bump may start to emerge (although some mums-to-be have mixed feelings about their changing shape); and partly because they get to see their baby for the first time at their dating scan and have proof that there really is a life in there!

Things to think about at the end of your first trimester:

A birth plan. Lots of mums-to-be write a birth plan then change it nearer the time, and for some it flies out the window on the day. It does help you to focus, though – and if, for instance, you think you'd like a water birth, it gives you time to research your options fully. Your birthing centre might have their own or you might have to hire and bring one in. If you're having a home birth you'll need to check sizes, weights and delivery arrangements.

• When to start your maternity leave. It might be that you want a chunk of time off before the birth: maybe you want a long last holiday or you need to arrange a house move; maybe you want to save it all up for after the baby's born; or maybe you think you might want to take a career break or give up work altogether. It's never too soon to look into all the possibilities.

• How your baby will fit into your home. Some couples decide they need to move house to make space for life with a newcomer; others convert a spare bedroom or study into a nursery; some people will need to do quite a bit of 'baby-proofing' before their home is baby safe.

• Antenatal classes. Even though you won't start antenatal classes until around week 27, they do tend to get booked up well in advance – especially the private ones such as NCT – so do your research and apply early. You might think you don't need any classes, but most women find them really useful and informative – and plenty of mums-to-be make great friends to see them through pregnancy and newborn days.

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