Time-line:
- Week 8: Your embryo, now the 6th week of development, is about the size of a grape. The arms have grown longer and bend at the elbows. The eyelid folds and ears are forming and even the tip of the nose is visible. Places where fingers and toes eventually will grow are becoming noticeable.
- Week 9: The embryo measures about 0.9 inches to 1.2 inches about the size of a size of a strawberry. The arms and legs are longer. The head is more erect and neck is more developed. The baby now moves its body and limbs, and this movement can be visible during an ultrasound, but the mother won't be able to feel the movements yet.
- Week 10: At week 10 the baby becomes a "fetus". It looks a little like a medium shrimp, measuring 1.25 to 1.68 inches from crown to rump, and weighing a little less than two-tenths of an ounce. The eyes are covered by skin that will eventually split to form eyelids.You will be happy to note that most physical malformations, when they happen, have occurred by the end of this week, so the most critical part of your baby's development is safely behind you. But other developmental processes, such as those affecting behavior and intelligence, will continue.
- Week 11: The fetus, about the size of a lime, measures about 1.75 to 2.4 inches from crown to rump and weighs about .3oz. Fingernails and external genitalia are showing distinguishing characteristics, and the baby is swallowing and kicking, although you still won't feel it.
- Week 12: The fetus now measures about 2.5 inches and is between three-tenths of an ounce and half an ounce. The fetus fully formed, from tooth buds to toenails, and your baby's job now is to continue getting larger and stronger for the rest of your pregnancy. With the fetus being fully developed, the chance of miscarriage drops considerably after this week.
- Week 13: the complete fetus, now in about its 11th week of development, measures 2.6 to 3.1 inches and weighs between half an ounce and seven-tenths of an ounce, about the size of a peach. The head is still abnormally bigger than the body, but the rest of the body is growing rapidly. In fact, your baby is growing tremendously these days. By this time all twenty teeth (baby teeth) have formed and are waiting. The face is starting to look more human, with eyes moving closer together. Toes and fingers are clearly separate, and ankles and wrists have formed. External genitalia are becoming visible.
- Week 14: Your baby measures about 3.2 to 4.1 inches from crown to rump now and weighs almost an ounce. The ears are shifting from the neck to the sides of the head, and the neck is getting longer and chin more prominent. Facial features and unique fingerprints are all there. Your baby is beginning to respond to outside stimuli. For Example if you poked your abdomen is , the fetus will try to wriggle away.
- Week 15: Your 13-week-old fetus now measures about 4.1 to 4.5 inches from crown to rump and weighs about 1.75 ounces.Your child may even be sucking his thumb by now. Its body is covered by an ultrafine hair, called lanugo, which is usually gone before birth. Eyebrows and hair on the top of the head are beginning to grow.
- Week 16: Your baby now measures about 4.3 to 4.6 inches from crown to rump and weighs about 2.8 ounces. Fingernails are well-formed and the lanugo, may grow on the head. The baby goes to the bathroom every 40-45 minutes. The nervous system is functioning and muscles are responding to stimulation from your baby's brain. You may be able to hear the baby's heartbeat in the doctor's office.