-
weeks 1-2
Development of baby weeks 1-2 -
Period: to
weeks 1-2
There is no development currently. The zygote travels through the fallopian tube toward the uterus. In the first round of cell division it is called cleavage. A cavity formed in the morula and it becomes a blastocyst. -
weeks 3-4
Development of baby weeks 3-4 -
Period: to
weeks 3-4
Baby is now known as a blastocyst and attaches itself to the uterus lining, this is called implantation. In the blastocyst the groups of cells rapidly growing, turn into an embryo. -
weeks 5-6
Development of baby weeks 5-6 -
Period: to
weeks 5-6
The baby's neural tube closes, the brain and the spinal cord begin to form. The heart, organs, and bones start to form. The arms and limb buds appear. The brain begins to develop as well as the heart. The eyes and ears also begin to form. During this stage the baby is about 1/6 inch. -
weeks 7-8
Development of baby weeks 7-8 -
Period: to
weeks 7-8
The baby's brain and face begin to grow. The four-chamber heart starts to appear. Lungs begin to form as well as fingers and toes. All the major organs are formed, lips and nose, and the ears begin to develop. -
week 10
Development of baby week 10 -
Period: to
week 10
All the internal organs are starting to work together. The head is half the size of the baby right now and the eyes, arms, and legs are identifiable. The brain is starting to become active. -
week 11
Development week 11 -
Period: to
week 11
Genitals in the baby develop as well as the formation of teeth buds. The head is half the length of the baby and the baby stands at 2 inches and 1/3 ounce. -
week 12
Development of baby week 12 -
Period: to
week 12
The fingernails have started to grow and the intestines are now found in the abdomen. The face is a more defined shape and the baby is 2 1/2 inches and 1/2 ounce. -
week 14
Development of baby week 14 -
Period: to
week 14
The baby's sex is now apparent and it can swallow and make its own urine. Baby is now 3 1/ inches and weighs about 1/2 ounce. -
week 16
Development of baby week 16 -
Period: to
week 16
The baby is now moving but the mother cannot feel it yet. Baby is at 4 1/2 inches and 4 ounces! -
weeks 18-19
Development of baby weeks 18-19 -
Period: to
weeks 18-19
The baby begins to hear and their digestive system works. Vernix caseosa covers the baby -
weeks 20-21
Development of baby weeks 20-21 -
Period: to
weeks 20-21
The baby now has regular sleep and wake patterns as well as all organs and structures forming. Breathing movements occur but are underdeveloped. The baby may begin to suck its thumb and is covered in lanugo. The baby stands at 6 1/3 inches and 11 ounces. -
week 22
Development of baby week 22 -
Period: to
week 22
The baby has fingernails, a fingerprint, eyebrows, and eyelashes. The baby is more active and the heartbeat can be heard with a stethoscope. Lowest limit of viability. The baby is about 7 1/2 inches and 1 pound. -
week 24
Development of baby week 24 -
Period: to
week 24
The lung development has started, regular sleep and wake patterns. The baby now has wrinkly skin that is translucent and pinkish-red. The baby is 8 inches and 1 1/3 pound. -
weeks 28-29
Development of baby weeks 28-29 -
Period: to
weeks 28-29
The baby's eyes begin to partially open. The central nervous system directs breathing and body temperature and the lungs can breathe. The baby now kicks and stretches and is at 10 inches and 2 1/4 pounds. -
weeks 31-32
Development of baby weeks 31-32 -
Period: to
weeks 31-32
The baby has finished most of its development. Rapid weight gain occurs in the baby as well as the lanugo starting to fall off. The baby is at 11 inches and 3 3/4 pounds. -
weeks 36-37
Development of baby weeks 36-37 -
Period: to
weeks 36-37
The baby now takes up most of the amniotic sac and starts to turn its head down to prepare for labor. The baby is now 13 1/2 inches and 6 pounds. The baby gains 1/2 pound every week until delivery. -
weeks 38-40
Development of baby weeks 38-40 -
Period: to
weeks 38-40
The brain, lungs, and liver are developing. The brain will double in size. Baby is now considered full term. The lung development during the last few weeks helps with complications after birth. Weight gain helps with temperature control.