-
Menstraul Cycle- Start of first trimester
Start of the period. Most doctors use the start of your last period to determine your due date. Women have periods because it is necessary for reproduction. The first five days of the cycle is bleeding and cramps. Days 6-10 the uterus lining thickens. Days 11-15 the woman is fertile. Days 16-28 the egg prepares to leave the body. The first day of the cycle is also considered the start of the first trimester, even though your egg hasn't been fertilized. -
Period: to
Pregnancy
-
Fertilization
The woman can now get pregnant. She had sex on this night with her husband and her egg was fertilized. The egg and sperm join to form a zygote. Their chromosomes mix and everything about the fetus is decided. From hair color, to eye color and how tall the child will be. The zygote now travels from the ovary to the uterus where it embeds itself it the uterin wall. This process is called implantation. -
Third Week of Pregnancy - Implantation
The placenta starts producing hCG which stops the production off eggs and tells your body to produce estrogen and progesterone. The amniotic sac starts forming around the fetus. For now, the fetus gets it oxygen and nutrients from microscopic tunnels in the uterin wall. -
Fourth Week of Pregnancy - Umbilical Cord Forms
The fetus' organs start to form and is vulnerable. The embryo has two layers, the epiblast and hypoblast which form the organs and body parts. Placenta starts forming umbellical cord. -
Fifth Week of Pregnancy - Heart Development, Backbone forms
Embryo begins to grow rapidly, has three layers: ectoderm, mesoderm and endoderm which will form all organs and tissues. Neutral tube begins to sprout which forms the nervous system and backbone in ectoderm. Heart and circulatory system start to form in mesoderm and begin to form chambers and beat. The endoderm begins to form the lungs, intestines, and urinary systems. -
Sixth Week of Pregnancy - Brain Development, Heart Beats
The nose, mouth and ears begin to form. The fetus' heart beats about 100-160 times per minute. Brain, muscles and bones form along with the pituitary gland. The fetus is now about a quarter of an inch long, and about the size of a lentil. -
Seventh Week of Pregnancy- Eyes and Pancreas form
Hands and feet begin to emerge from the developing arms and legs. The embryo still has its tail which is an extension of the tail bone. The eyelids and eyes are forming and the eyes are starting to get color. The fetus now has an appendix and a pancreas. The intestines are bulging out into the umbilical cord. -
Eighth Week of Pregnancy- Fingers, Toes, and Breathing Tubes form
Webbed fingers and toes begin to come out of the hands and feet. Eyelids almost cover the whole eye, breathing tubes run from the throat to the lungs and the tail is almost gone. Nerve cells in the brain reach out and connect. The fetus begins to move, although the mother can't feel it yet. -
Ninth Week of Pregnancy- Organs begin to function
The fetus is now about the size of a grape and is beginning to look like a human. The heart is finished dividing into four chambers and valves and teeth start to form. The tail is gone and the organs, muscles and nerves begin to function. External sex organs are present, but not visible yet and the eyes are completely formed. The fetus can now start producing hormones and gaining weight. -
Tenth Week of Pregnancy- Swallow, Finger nails form, Limbs bend
Most critical part is finished, now the fetus can rapidly grow and mature its organs and tissues. The fetus begins to swallow fluid and kick. Nails are beginning to form and the baby is starting to be covered in peach-like hair. The fingers and toes start to lose the webbing. The limbs can bend and the outline of the spine is visible. The fetus is about an inch long and the size of a kumquat. -
Eleventh Week of Pregnancy- Stretching and Kicking, Hiccup
The fetus is almost ready to start opening and closing its hands. Teeth buds are starting to appear in the gums and bones are beginning to harden. The baby is stretching and kicking and will become more frequent as it develops and grows. The diaphragm is also forming and the baby will begin to hiccup. -
Twelfth Week of Pregnancy- Reflexes Develop, Grasp, Kidney Produces Urine. End of first trimester
Reflexes begin to develop rapidly. The baby's fingers and toes are now able to move freely, the eye muscles will clench and it will start making sucking movements. The intestines start to move into the abdominal cavity and kidneys will begin to excrete urine into the bladder. Nerve cells multiply rapidly and synapses are forming. The baby is about 2 inches long and weighs half an ounce. This is the end of the first trimester. -
Thirteenth Week of Pregnancy- Second Trimester
Start of the Second Trimester. Fingerprints have formed on the baby's fingers and veins and organs are visible throught the paper-thin skin. If it's going to be a girl, she now has more than 2 million eggs in her ovaries. -
Fourteenth Week of Pregnancy- Squint, Grimace, Frown, Pee, Suck Thumb, Lanugo forms
The baby can now squint, grimace, frown, pee and possibly suck its thumb. The kidneys produce urine and the baby releases it into the amniotic sack around it. It now has a more defined neck, its arms are proportional, and it now has hair all over its body called lanugo. The liver starts producing bile and the spleen starts producing red blood cells. The baby's hands and feet are now more active. -
Fifteenth Week of Pregnancy- Breath amniotic fluid, form taste buds
The baby is moving amniotic fluid through its upper respiratory tract and helps the lungs develop. The legs are growing proportional and it can move all its joints and limbs. It can sense light and is forming taste buds. You may be able to tell if its a boy or a girl, depending on the clarity of the ultrasound picture and the position of the baby. -
Sixteenth Week of Pregnancy, start of growth spurt
The baby is about 4 1/2 inches long and weighs 3 1/2 ounces. Its about to hit a growth spurt over the next few weeks and is beginning to look more like a human. -
Seventeenth Week of Pregnancy, Sweat Glands develop
The umbilical cord and bones begin to thicken. Starting to move all its joints, and the sweat glands begin to develop. -
Eighteenth Week of Pregnancy- Sex determination with ultrasound
The baby becomes more active and is beginning to get big enough that the mother can feel it moving. The ears come to their final position and myelin is beginning to form around its nerves for protection. A girls uterus and fallopian tubes are in place and a boys genitals are noticeable. -
Nineteenth Week of Pregnancy- Vernix is formed
The brain is now making special places for smell, taste, hearing, vision and touch. Hair on the sclap begins to sprout and a waxy, protective, skin like material called the vernix is beginning to cover the body. -
Twentieth Week of Pregnancy
The baby is about 6 1/2 inches long and weighs about 10 1/2 ounces. It begins to swallow more and produces meconium, which is a by-product of digestion. -
Twenty-first Week of Pregnancy
The baby begins to kick, but nothing compared to what it will do later on. The eyebrows and eyelids are present now and a girls vagina will have formed. -
Twenty-second Week of Pregnancy
Everything is becoming more distinct. The pancreas begins to develop steadily. -
Twenty-third Week of Pregnancy, Hearing
Blood vessels in the lungs begin to prepare for breathing and the baby can hear more and more sounds. -
Twenty-fourth Week of Pregnancy
The baby is just over a pound and about 1 foot long. The lungs are beginning to develop braches off the respiratory tree. -
Twenty-fifth Week of Pregnancy- Fat gain
Beginning to gain some "baby fat" and wrinkled skin will begin to smoothe out. The hair keeps growing and is beginning to get color and texture. -
Twenty-sixth Week of Pregnancy
The baby's ears become more sensitive and is inhaling and exhaling amniotic fluid to help develop its lungs. It continues to gain body fat and if its a boy, the testicles descend into the scrotum. -
Twenty-seventh Week of Pregnancy- End of Second Trimester
The baby begins sleeping and waking at regular intervals, opening and closing eyes, and sucking its thumb. Its brain is becoming more active and the baby begins to hiccup more regularly. End of the Second Trimester. -
Twenty-eighth Week of Pregnancy- Start of third trimester, Sight
Start of the Third Trimester. The baby weighs 2 1/4 pounds and about 14.8 inches. It now has eyelashes and can blink its eyes. Continuing to add fat, the baby is still growing rapid and can see light from outside the womb. -
Twenty-ninth Week of Pregnancy
The baby's head grows as a result of his brain developing. The mother has to eat heathly to support the rapid growth and need for nutriets. -
Thirtieth Week of Pregnancy
The baby's eyesight is still developing and when the baby is born, it will have 20/400 vision. -
Thirty-first Week of Pregnancy
The baby is still having a growth spurt, but is about to hit another, bigger one. The mother may have trouble sleeping because the baby is so active. -
Thirty-second Week of Pregnancy
The baby weighs about 3 3/4 pounds and is about 16.7 inches long. The mother gains about a pound a week and half of that goes to the baby. It now has real hair and its skin becomes smooth. -
Thirty-third Week of Pregnancy
The bones begin to harden, but the bones in the skull haven't fused yet which will help the baby exit the mother during birth. -
Thirty-fourth Week of Pregnancy
The baby's fat layers are getting bigger, and it makes the baby look chubby. The central nervous system and lungs are maturing. -
Thirty-fifth Week of Pregnancy
The baby doesn't have much room to move around anymore, but the number of times it kicks won't change. The kidneys are fully developed and the liver can process some wastes. Most physical developments are complete, the next weeks will be spent putting on weight. -
Thirty-sixth Week of Pregnancy
The baby weighs about 6 pounds and is more than 18 1/2 inches long. It sheds most of the covering of hair as well as the vernix and swallows both of these. The baby should be in a head down position and is ready to leave the body. -
Thirty-seventh Week of Pregnancy
The baby continues to grow and is now considered "full-term" and could be delivered at any time and be able to live. The baby most likely has hair, but most of the time its not like the parents. -
Thirty-eighth Week of Pregnancy- growing slows
The baby weighs about 6.8 pounds and has a firm grip. When the baby is born, you may not be able to tell what color of eyes it will have. They may change becuase they add pigment. Growing slows down -
Thirty-ninth Week of Pregnancy
The baby continues to build fat which will help it control its body temperature when it gets outside of the mother. The outer layers of skin begin to fall off as the baby gets new layers of skin. -
Fourtieth Week of Pregnancy
The average newborn weighs 7 1/2 pounds and is about 20 inches long. The baby's skull isn't fused and when its born, it may look "cone headed". -
Fourty-first Week of Pregnancy
The baby can't stay in the womb forever, and if the baby isn't born in the next week, the doctor may want to induce labor.
