During this week, your baby’s brain will begin to grow rapidly. This rapid growth continues until your child is five years old. In addition, your baby’s lungs will begin to secrete surfactant - a substance that allows the lungs to inflate.
The baby may be roused from sleep by external sounds or movements: sudden loud noises, loud music, even the vibrations of a car or washing machine can stir the baby into activity.
By now your baby’s head hair will be visible and the eyebrows are beginning to show. No matter how dark its hair will become, the baby’s hair is now completely unpigmented and a translucent blond or white.
Even though its eyelids are fused, the baby is now making blinking movements. The size and strength of your baby’s hands have improved so that by now, it can grip with some force.
By this time in pregnancy, iron deficiency anemia may develop. More than 90 percent of women may be slightly anemic before they become pregnant, and about 20 percent of women are treated for iron-deficiency anemia during their pregnancy. If you don’t have sufficient iron in your diet, your body doesn’t produce as many red blood cells, and fewer red blood cells means less circulating oxygen in your system. Women with anemia may feel weak, tired, and out of breath and may even faint.
At the end of this fifth month of pregnancy, your uterus has reached your belly button. The baby in that uterus measures about 190mm in length and is about the size of a Barbie or Ken doll. In less than two weeks, the baby has gained more than 100g. Right now your baby weighs about the same as a medium iceberg lettuce.