Pregnancy Information Center

Information, Symptoms, Treatments and Resources


Your First Trimester - Week 12


Week 12


What's Happening To Your Body

Congratulations, it’s the last week of your first trimester! You may start to feel your energy return to pre-pregnancy levels. Many, though not all, women experience little, if any, fatigue and nausea at this point in the pregnancy. You may also take fewer trips to the bathroom as your uterus shifts up and forward, away from the bladder. But don't get too comfortable — by the third trimester, the baby and uterus will be big enough that they will be pressing on the bladder, sending you back to frequent bathroom runs.

You may find yourself getting headaches or feeling lightheaded. This is from your increase in blood volume. Remember to be cautious and not stand up too quickly.

Pregnancy can cause changes in the skin. Many women develop a dark line from the belly button downward; this is known as a linea nigra. Your face may take on a “glowing” appearance. Increased blood volume and hormones work together to increase oil gland secretion, the combination of which leads to a “pregnancy glow.”

You may also start developing dark patches on the face and neck, known as melasma, or the “pregnancy mask.” This discoloration will disappear or lighten significantly once your pregnancy is over.

Starting this week, your doctor may offer you a nuchal translucency test, which checks for Down syndrome in your baby.


What's Happening To Your Baby

Your baby is the size of a lime. Your baby is now approximately 2.5 to 2.8 inches (6.4 to 7 cm) long from crown to rump. At this point, your baby should weigh about 0.3 to 0.5 ounces (8.5 to 14.2 grams).

At week 12, your baby is fully formed. Though its brain and organs will continue to grow and develop, it has all the necessary pieces. However, it wouldn’t be able to survive outside of the womb yet. Your baby’s brain will continue to grow from this point on but will maintain its current shape. The pituitary gland, located at the base of your baby's brain, is also beginning to produce hormones this week.

Your baby has also started developing nerves and a spinal cord, which allows him or her to feel some types of pain. Fingers and toes have separated and hair and nails are starting to form.

Your baby’s vocal cords also form this week. In addition, In addition, the kidneys begin to function and the baby starts passing out amniotic fluid as urine. Your baby’s digestive tract is also strengthening.

Most importantly, your baby’s heart is beginning to pump several quarts of blood daily. This can be heard with the aid of a doppler (a special listening device). The heartbeat will be very fast, like the clicking of horse hooves.

The external genitalia have also developed and will begin showing signs of either the male or female sex. Though your healthcare provider may guess the gender, there is still a lot of uncertainty.

Read This Next: Week 13

In Case You Missed It: Week 11

Explore More In Our Hep C Learning Center
image description
What Is Hepatitis C?
Learn about this treatable virus.
image description
Diagnosing Hepatitis C
Getting tested for this viral infection.
image description
Just Diagnosed? Here’s What’s Next
3 key steps to getting on treatment.
image description
Understanding Hepatitis C Treatment
4 steps to getting on therapy.
image description
Your Guide to Hep C Treatments
What you need to know about Hep C drugs.
image description
Managing Side Effects of Treatment
How the drugs might affect you.
image description
Making Hep C Treatment a Success
These tips may up your chances of a cure.