Week 6Your baby's jaw, cheeks, chin, eyes, ears, and nose are beginning to form what will eventually become one adorable face. In addition, her kidneys, liver, and lungs are developing, and her heart is now beating 80 times a minute (and getting faster every day). All this and she's still no bigger than the length of a nail head (about a quarter of an inch) from crown to rump!
Week 9Your baby, now the size of a green olive, has grown about an inch since last week. Tiny muscles are beginning to form, so while he might not be ready to pump iron, he's gearing up to move his arms and legs. It's still too soon to feel anything in your belly, but you might be able to hear something at your next checkup. Try listening for your baby's heartbeat via a Doppler device — that welcome sound should be audible anytime now.
Week 12Your baby weighs a full half-ounce and is about the size of a large plum. Most of his systems are in place, though there's still maturing to do. First, his fetal digestive system is beginning to practice contraction movements for eating. His bone marrow is busy making white blood cells. The pituitary gland has started producing the hormones that'll enable him/her to make babies of his/her own
Week 16Your baby now weighs 3 to 5 oz. He's four to five inches in length. The bones that are in place in his ears means he can hear your voice. While he’s getting used to your voice, the tiny muscles in his body, and the ones in his back, are gaining strength, so he can straighten out a more. Your baby is capable of making a few face expressions. His eyes are finally working, making small side-to-side movements and perceiving light.
Week 20Your second trimester ultrasound, scheduled for between 18 and 22 weeks to see what's happening. A girl have her uterus is now fully formed and her ovaries are holding about seven million primitive eggs. A boy have his testicles begun their descent from the abdomen to the scrotum.Your baby is weighing about ten oz. and six and a half inches tall, there's still plenty of growing room in there, which allows him to twist and turn.
Week 24Your baby is about eight and a half inches long and weighs one and a half pounds, gaining at a rate of six ounces per week. Much of that weight comes from accumulating baby fat, as well as from growing organs, bones, and muscle. Those little ears of hers can hear very loud sounds. By now, the face is almost fully formed, complete with eyelashes, eyebrows, and hair. Her locks are white since there's no pigment yet.
Week 28Your baby is settling into the proper position for birth, with his head facing downward. Your little work in progress is now about 2.5 pounds and almost 16 inches long. He's busy adding new skills such as blinking to an already impressive repertoire of tricks like coughing, sucking, hiccuping, and taking practice breaths. Your baby's sleep now includes the REM (rapid eye movement) phase — and that means he could be dreaming already.
Week 32She's tipping the scales at almost four pounds and just about 19 inches. In these past few weeks, it's all about practice, practice, practice as she hones the skills she'll need to thrive outside the womb — from swallowing and breathing to kicking and sucking. Speaking of sucking, your little one has been able to suck her thumb for a while now. As more and more fat accumulates under your baby's skin, she's becoming more opaque.
Week 36Forget your aches by trying to focus on your baby, who is now about six pounds and 20 inches long, with soft bones and cartilage to allow a safer journey through the exit door. Most of her systems (from circulatory to musculoskeletal) are ready for prime time, though her digestion system — which has done only practice runs so far — will kick into gear as she takes her first suckle at the breast or bottle.
Week 40This week is the end of your pregnancy. He weighs from six to nine lbs and between 19 and 22 inches. The bones in his skull haven’t fused yet. He has enough fat under the skin to maintain his body temperature. You are still providing the antibodies he’ll need to fight off infections for the first six months. If you plan on breastfeeding, your milk will be giving him more antibodies that’ll boost his immune system.