12th Week

Your Body Week 12
Your uterus has now enlarged so that it protrudes above your pelvic bone. You may have begun to "show". It may be time to buy some maternity clothes!

Your doctor or midwife can feel the baby by external examination around this time.

Your heart is working harder to pump the increased volume of blood around your body and as a result your body temperature has risen. Your heart rate may have increased by a few beats per minute to cope with the increased blood volume circulating throughout your body.

Morning sickness may decrease and you may not need to urinate as much as in early pregnancy. You may become constipated, however, as bowel movements slow down in pregnancy.

You may notice a dark line, called the linea nigra, running along your abdomen from your navel to your genital area. The linea nigra shows where your abdominal muscles are stretching to allow for your uterus to grow. The linea nigra may remain for a little while after the birth of your baby, but over time it will fade.

Your Baby Week 12
The end of the twelfth week of pregnancy marks the end of the first trimester. Your baby is now almost 2.5 inches long (6.1cm) when measured from crown to rump, and weighs between 0.3 and 0.5 ounces (9 to 13g).

Your baby's fingers and toes have separated and are getting longer. Your baby can open and close its mouth and drinks amniotic fluid which it passes out as urine. Its head is becoming more rounded, though it is still large in proportion to its body. It has eyelids.

You can now hear your baby's heartbeat with a Doppler Ultrasound device!

Your baby continues to grow rapidly and has doubled in size in the last three weeks alone.

The face is beginning to look more human, and all body structures are present with a few refinements still in progress. Fingernails and toenails begin to develop this week.

Your baby's muscles are sufficiently developed to allow for involuntary movements at this time. The messages which control your baby's movements are sent from the spine, rather than the brain, which is not yet sufficiently developed.