As your baby’s ear bones begin to harden this month, he may begin to hear some sounds. Hearing will not be complete until the seventh month. The lungs also continue development, and as a part of that you baby will “breathe” amniotic fluid.
His face, right down to the external ears will be well developed. He can frown, squint and grimace. Although he cannot see yet, his retinas are becoming sensitive to light. Eyebrows and scalp hair are beginning to appear. He can even suck his thumb.
At the end of the sixteenth week your baby will be around 5.5 inches from crown to rump and weigh 6 oz, and baby is now big enough that his heartbeat can be heard with a regular stethoscope.
Around this time you may notice some changes in your skin. Your nipples may darken, and the veins will be more prominent. You may also begin to see blotchy skin on your face. Some experts say this is normal, others say it may signal a deficiency in your diet.
Your uterus and skin need twice as much blood as usual, and your kidneys need 25% more blood than usual. This means your heart is working twice as hard just to meet your bodies’ regular demand. Your uterus has outgrown your pelvis and will be forced into the abdomen, which will decrease your lung capacity. If you engage in regular activity, you may find that you are breathless easier and fatigue easier than you did before you were pregnant. It is important that you begin using this as an indicator of when to slow down or end an activity.
Some mothers are able to recognize the baby’s movements during the fourth month, although it is normal not to recognize it until the fifth month. It may feel like bubbles or butterflies fluttering in your belly.
These symptoms are commonly experienced during this month.