I now weigh about 4 3/4 pounds and I am almost 18 inches long. My fat layers — which will help regulate my body temperature once I am born — are filling me out, making me rounder. My skin is also smoother than ever. My central nervous system is maturing and my lungs are continuing to mature as well.


This week I weigh a little over 4 pounds (the size of a pineapple) and have passed the 17-inch mark. I am rapidly losing that wrinkled, alien look and my skeleton is hardening. The bones in my skull aren’t fused together, which allows them to move and slightly overlap, thus making it easier for me to fit through the birth canal. (The pressure on the head during birth is so intense that many babies are born with a cone-head like appearance.) These bones don’t entirely fuse until early adulthood, so they can grow as my brain and other tissue expands during infancy and childhood.

By now, I weigh 3.75 pounds (pick up a large jicama) and I am about 16.7 inches long, taking up a lot of space in my Mommy’s uterus. Mommy is gaining about a pound a week and roughly half of that goes right to me. In fact, I will gain a third to half of my birth weight during the next 7 weeks as I fatten up for survival outside the womb. I now have toenails, fingernails, and real hair (or at least respectable peach fuzz). My skin is becoming soft and smooth as I plump up in preparation for birth.

This week, I measure over 16 inches long. I weigh about 3.3 pounds (try carrying 4 navel oranges) and I’m heading into a growth spurt. I can turn my head from side to side, and my arms, legs, and body are beginning to plump out as needed fat accumulates underneath my skin. I’m moving a lot, too, so Mommy may have trouble sleeping because my kicks and somersaults keep her up. Take comfort though Mommy, all this moving is a sign that I am active and healthy.

This week I’m about 15.7 inches long, and I weigh almost 3 pounds (like a head of cabbage). A pint and a half of amniotic fluid surrounds me, but that volume will decrease as I get bigger and take up more room in Mommy’s uterus. My eyesight continues to develop, though it’s not very keen; even after I’m born, I will keep my eyes closed for a good part of the day. When I do open them, I’ll respond to changes in light but will have 20/400 vision — which means I can only make out objects a few inches from my face.

I now weigh about 2 1/2 pounds (like a butternut squash) and am a tad over 15 inches long from head to heel. My muscles and lungs are continuing to mature, and my head is growing bigger to make room for my developing brain. Because my bones are soaking up lots of calcium, mommy needs to drink lots of milk (or find another good source of calcium, such as cheese, yogurt, or enriched orange juice). This trimester, about 250 milligrams of calcium are deposited in my body’s hardening skeleton each day.