1st trimester: Week 13

Your Baby

As the second trimester begins, your baby is growing quickly. She weighs about three-quarters of an ounce and measures between 2 1/2 to 3 inches from the top of her head to her bottom. She's in her fetal period, when the organs and tissues that took shape in the first trimester start to develop. Her intestines, originally part of the umbilical cord, have found a new home in her abdominal cavity. Her tongue and vocal chords are also getting ready for their debut at birth, and her eyes are moving closer together. Her ears are in place, and her head is roughly half the size of her whole body. (By birth, her head will be one-fourth the size of her body.)

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Your Body

If you have a checkup this week, your doctor or midwife may be able to feel the top of your uterus in the lower half of your abdomen. As it grows, your uterus will fill your pelvis, expanding up and out, and soon you'll definitely look the part of a pregnant woman.

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Do's and Don'ts

Do sign up now for childbirth classes, even though you won't be attending them for weeks (they usually begin in the seventh month). They're so popular that sessions fill up quickly. It's best to plan ahead to get the time slot that works best for you. Ask your doctor or midwife for a recommendation, or call your hospital or birthing center.

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