Pregnancy Week Thirteen
By the time you are 13 weeks pregnant, you have more or less begun your fourth month. You've also started the second trimester. In this trimester, you'll begin to really look pregnant (as opposed to slightly overweight) and (hopefully) you'll notice an improvement in your morning sickness and other pregnancy symptoms.
What Your Baby Looks Like
Beginning in week 13 and continuing for the rest of the fourth month (which runs from now until week 16 or 17 approximately), your baby will go through lots and lots of changes.
Your baby's body and bones - By now, his body is starting to catch up with his head in terms of size; in fact, of the two, his body his growing more quickly. His bones are developing as well - bone tissue is growing around his head and little ribs may be beginning to form.
Your baby's breathing apparatus - Your baby may even make some breathing movements in preparation for the real thing after delivery. In the meantime, all the oxygen and nutrients he needs are being supplied through the placenta which is now working at full tilt to support your baby's growth.
Your baby's sexual organs - by now, your baby will have external genitalia visible on an ultrasound exam. If you're carrying a baby girl, by week 13, her uterus may be developing and her ovaries already stocked with what will later become her eggs.
Your baby's movements - by now, your baby can move his arms and legs - you might even be able to feel these movements by the end of the fourth month. Your baby also has finger prints. He may even be able to suck his thumb.
Your baby's eyes - your baby's eyelids are still sealed shut to protect the eyes which are developing behind them.
By the end of this month, your baby will probably be around five inches long and weigh approximately five ounces.
Your Pregnancy Body
If you're lucky, you may start to feel a lot better in week 13 and for the rest of the second trimester. Many pregnant women find that by the time they reach four months, they are less nauseous and have more energy. Nevertheless, you are of course going to have some pregnancy symptoms (the expanding belly is one - your uterus is now the size of a small melon)!
Pregnancy symptoms typical for week 13 and beyond are:
Lessening morning sickness
Less frequent need to urinate (your uterus is now growing outwards and isn't pressing as hard on your bladder)
A variety of digestive problems including constipation, heartburn, etc
Bigger breasts which will continue to grow (but will hopefully be less tender)
Weight gain, and possibly the need to buy some larger clothes
A bigger appetite (be sure to eat healthily)
Dizziness, particularly if you move quickly from a lying or sitting to a standing position
Blocked ears and sinuses and perhaps even nosebleeds
Swollen hands and feet, and perhaps face
White discharge from the vagina
Check out our page on pregnancy week 16 for a list of tests you should have had done by the end of the fourth month of pregnancy.