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begining of last menstal cycle
The first week begins when your last period begins. You are not yet pregnant. -
proliferative phase
the phase of the menstrual cycle after menstruation. Under the influence of follicle-stimulating hormone from the pituitary, the ovary produces increasing amounts of estrogen, causing the lining of the uterus to become dense and richly vascular. The phase is terminated by rupture of a mature follicle and subsequent ovulation. -
ovulation
ovulation occurs about halfway through your menstrual cycle. This is the most fertile phase. -
fertilization
The union of male and female gametes to form a zygote, a process that begins with the penetration of the secondary oocyte by the spermatozoon and is completed with the fusion of the male and female pronuclei. -
3 weeks
Your baby-in-the-making is a ball of cells called a blastocyst. The blastocyst already contains a full set of DNA from you and your partner, which determines sex, eye color, and other traits. -
implantation
the very early stage of pregnancy at which the embryo adheres to the wall of the uterus. -
week 4
The ball of cells has officially become an embryo and is about the size of a poppy seed. Over the next six weeks, all of your baby's organs will begin to develop, and some will start to function. -
Week 5
Your baby's tiny heart begins to beat – at twice the rate of yours. His entire "body" is only about the size of a sesame seed. Bones and muscles begin to form. Head is growing rapidly. The brain and spinal cord begin to grow but will change all the way up to birth. -
Week 6
Facial features (like eyes and nostrils) are beginning to form, and little buds appear where arms and legs will develop.The digestive track forms. -
Week 8
Arms and legs are growing, and your baby now has little fingers, as well as a nose and upper lip. He's moving quite a bit now, but you won't feel it. He's about 5/8 of an inch long and weighs hardly anything – four-hundreths of an ounce. The embryo becomes a fetus. -
Week 9
Eyes have developed, though your baby's eyelids are fused shut for now. She's lost her "tail" and is starting to look more human. The fetus is floating in the amniotic fluid and is nurished from the placenta through the umbelical cord. -
Week 10
The embryo has become a fetus. His vital organs – such as kidneys, intestines, brain, and liver – are starting to function. Tiny fingernails and toenails are forming -
Week 11
Your baby is almost fully formed. Her bones are beginning to harden, and her genitalia are developing externally. She can hiccup, though it's too soon for you to feel it. -
Week 12
you can hear your baby's heartbeat. Your baby's just over 2 inches long and weighs about half an ounce. First Trimester is over. second trimester has started -
Week 14
Your baby's kidneys are producing urine, and he releases it into the amniotic fluid. He can make facial expressions and may have discovered thumb-sucking. -
Week 16
Your baby's sex may be detectable at your mid-pregnancy ultrasound, which typically happens between 16 and 20 weeks. The baby starts to get senses like touch, hearing, sight, taste, and smell. -
development of lanugo
Lanugo is developed at this time. Lanugo is a layer of fine hair that covers the body while the baby is in the womb. It helps to hold the vernix in place to ensure your baby's delicate skin doesn't become chapped by the long immersion in amniotic fluid -
Week 23
Your baby's sense of movement has developed, so he can feel the motion if you dance. His sense of hearing continues to improve. You may sometimes be able to see him squirming under the surface of your belly. At this point, a fetus can be delivered prematurely and have a ten to twenty percent chance of surviving. -
Week 27
Your baby's been doing "practice breathing" by inhaling and exhaling amniotic fluid, and if he was born now his lungs could function. He can also open and close his eyes. second trimester is over. third trimester begins. The Vernix, a cheesy, white substance that covers a baby's skin at birth, acts like a waterproof barrier on your baby's skin, protecting it from the drying effects of months of submersion in amniotic fluid. -
Week 28
Your baby may be dreaming. She has eyelashes, and her eyesight is improving. She weighs about 2 1/4 pounds and is about 15 inches long, head to heel. -
Week 32
He has grown finger nails and toenails. He is almost 17 inches long. and weighs about 3 3/4 pounds. -
Week 37
Your baby is now considered full-term. His lungs should work fine if he's born now, but ideally he'll stay in your womb a bit longer. -
Week 40
Your baby is due and fully ready for life outside the womb. The first stage of labor begins when you start having contractions that cause progressive changes in your cervix and ends when your cervix is fully dilated. The second stage of labor begins when you're fully dilated and ends with the birth of your baby. This is sometimes referred to as the "pushing" stage. The third stage of labor begins right after the birth of your baby and ends with the delivery of the placenta. -
Birth Week 40
The average weight of a newborn is about 7 1/2 pounds, and the average length is about 20 inches.
