Week 13

This is the last week of your first trimester and your baby weighs 14 to 20 grams. The crown-to-rump length of your growing baby is 2.6 to 3.1 inches. Your baby is now about the size of a peach. Fetal growth is amazing from now through about the 24th week of pregnancy.

A 13 week old fetus by SONOReal 3D ultrasound imaging

At this point of your pregnancy, there is a steady flow of pregnancy hormones in your bloodstream. Your body will adjust to the changes and morning sickness might stop and other early symptoms will begin to ease. Because the second trimester is approaching, feelings of anxiety or nervousness may also diminish. You have probably gained some weight by now. You are losing your waist and your clothing is probably fitting snugly.

There is a milky membrane that surrounds your baby. It is pierced by the umbilical cord and is made up of two layers, which are fused together. Your placenta provides most of the nutrients and oxygen that your baby needs. By this week, the placenta is well formed and ready to take over hormone manufacture from your ovaries. The placenta will produce progesterone and estriol. These hormones will be crucial in the maintenance of your pregnancy. Tissue that will form your baby’s bones is being laid down, especially around the head and limbs. The nose and chin are becoming more prominent. Your baby’s eyelids meet and fuse together and they will not open again for nearly four months. The eyes started out on the side of your baby’s head and they are now moving closer together on the face. The ears come to lie in their normal position on the sides of the head. If examined outside of the womb, you will be able to distinguish male from female at this time.

The sockets for all twenty teeth are formed in the gums, and vocal cords are beginning to form.

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  1. casanova 26 February 2015

    Hello ladies, this is my 3rd time pregnant and in every pregnancy I come to this website. However this time around seems to be a lot quieter. Where are all the pregnant women!! I met some awesome friends here and we went through the whole pregnancy together. Hope everyone is doing well. And I cant wait for Monday when I move on to my next week.

  2. txmama27 28 February 2015

    13 weeks tomorrow. I was on the page with all 3 pregnancies and more active with my last. I met some great friends who I am still in contact with daily. Love it. This is my 4th baby due sept 5th. Not much talking this time around tho. Hoping it gets more active as due dates get closer

  3. Janet8 03 March 2015

    Hi ladies! just checking in. Is there a FB page that you're on? it is super quiet in here! This page has been a wonderful resource for my last two pregnancies.

  4. casanova 04 March 2015

    Hello ladies, haven't had much time to get online. However, its great to see some activity going on. Now with FB and apps, not much goes on in here. Anyways on Monday I move to 15 weeks which makes it closer to the ultra sound that will reveal the gender. I hope everyone is doing well. I just wish I weren't so hungry all the time!!

  5. AMV 15 March 2015

    Hello Im new to this site. Im very excited to be on there is a lot of great information!! I am one day shy of being 13 weeks :)

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