First Trimester Quiz

A trimester is a three-month period of time; human pregnancies are comprised of three trimesters, or about 266 days.

A fertilized egg becomes a one-celled organism called a zygote, which has 23 chromosomes from you and 23 chromosomes from your partner.

During the fifth week of pregnancy, a baby's brain, spinal cord, heart and other organs begin to form.

For many pregnant women, morning sickness is a misnomer because they feel nauseous through the day or night.

During pregnancy, it takes longer to digest your food so your baby can absorb more of the nutritents. This also means you're at increased risk for heartburn.

Your baby's 10 "little piggies" start forming during the ninth week of your pregnancy.

Go to the bathroom whenever you feel the urge. Your growing uterus is putting pressure on your bladder and you could cause a bladder infection by holding it too long.

The moment an egg is fertilized, your baby's gender is determined. From the start, your baby was destined to be a boy or a girl -- but you won't know until the second trimester.

Your baby's fingernails begin to grow during Week 12 of your pregnancy, about the time his or her body reaches about 2.5 inches (6.35 centimeters) in length.

As early as 14 weeks' gestation, a baby can begin sucking his or her thumb.