Congratulations on being 12 weeks pregnant with Twins! It’s an exciting yet overwhelming time, with so much to learn about the Twins fetal development and we are here to help you every step of the way.

By 12 weeks, your twins will each measure about 5.4cm (2.1in) from head to bottom (crown to rump). However, it’s common for one twin to be a bit bigger than the other. You may even see this difference in size at your dating scan.

Provided the size difference between your twins is small, there’s no need to be concerned. Your midwife will be happy to reassure you if you have any worries.

Your babies’ faces are now looking much more human. Their eyes, which started out on the sides of their heads, are now closer together. And their ears are almost in their final position.

Your twins’ fingers and toes are no longer webbed. And although their genitals are still developing, they’ve already started to show some male or female characteristics.

Inside your babies’ tiny bodies, their intestines have moved into their abdomens. Their livers are making enzymes, a substance which helps the organ do its job properly, and their kidneys are producing wee.

The wee that your twins make will end up in the amniotic sac or sacs. It will make up most of your amniotic fluid during the second half of your pregnancy. Your babies will breathe and swallow this fluid, giving their lungs and digestive systems plenty of practice for life outside the womb (uterus).

Your twins have already started hiccupping, although you probably can’t feel it yet. Hiccups help to train your babies’ diaphragms, which they’ll use for breathing as soon as they’re born.

Your babies’ brains are starting to form connections, and your twins are gradually developing more reflexes. They can already open and close their hands, and curl their tiny toes.

For these and more fascinating facts, be sure to see the Baby Centre.

Twin Classes

Now is a great time to start educating yourself on the wonderful world of Twins. Join our local group classes worldwide or stay in the comfort of your home and login to our live online classes. Let us support you on your journey to multiples and beyond!