This is a big week for your baby: Your little one's key body systems and vital organs have formed! If you haven't already, you'll be able to hear fetal heart activity at your next prenatal checkup.
Meanwhile, at 12 weeks pregnant, your baby bump may be looking a little more pronounced.
Your Baby at Week 12
At a Glance
12 weeks pregnant is how many months?
If you're 12 weeks pregnant, you're in month 3 of your pregnancy. Only 6 months left to go! Still have questions? Here's some more information on how weeks, months and trimesters are broken down in pregnancy.
How big is my baby at 12 weeks?
By now your baby weighs a full half-ounce, with a crown-to-rump length of 2 to 2¼ inches: about the size of a lime.
It's hard to believe — especially from the outside, since you're probably barely showing at this point — but your baby has more than doubled in size during the past three weeks.
Baby’s digestive system begins working
This week marks a turning point for your baby. At 12 weeks pregnant, the Herculean task of developing new bodily structures is nearing an end, as most of your baby's systems are fully formed — though there's still plenty of maturing to do.
Now comes the maintenance phase, during which your fetus' systems continue to evolve for the next 28 weeks and the organs get to work. For one thing, the fetal digestive system is beginning to flex its muscles — literally — as it starts practicing contraction movements, a skill your little peanut will need after birth to push food through the digestive tract.
The bone marrow is busy making white blood cells — weapons that will one day help your baby fight infection once she's out of your safe haven and in a regular play group. And the pituitary gland at the base of the brain has started producing the hormones that'll enable her to make babies of her own in a few decades or so.
Fetal cardiac activity ramps up
If you haven't already had the pleasure, it's likely that at this month's checkup you'll hear sounds of fetal cardiac activity — a noise that will make your heart race with joy!
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