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Fertilization -
The action or process of fertilizing an egg, female animal, or plant, involving the fusion of male and female gametes to form a zygote -
Implantation 3 -weeks
Implantation is the attachment of the fertilized egg when the fertilized egg ( now called a blastocyst ) has completed its travel through the fallopian tube and adheres to the lining of the uterus . -
Week 4 Development
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Week 5
Deep in your uterus your embryo is growing at a furious pace. At this point, he's about the size of a sesame seed. He's now made up of three layers the ectoderm, the mesoderm, and the endoderm which will later form all of his organs and tissues. The neural tube from which your baby's brain, spinal cord, nerves, and backbone will sprout is starting to develop in the top layer, called the ectoderm.His heart and circulatory system begin to form in the middle layer, or mesoderm. -
Week 6
This week's major developments: The nose, mouth, and ears that you'll spend so much time kissing in eight months are beginning to take shape. Right now, your baby is a quarter of an inch long, about the size of a lentil. His heart is beating about 100 to 160 times a minute almost twice as fast as yours and blood is beginning to course through his body. -
Week 7
Your baby has doubled in size since last week and now measures half an inch long, about the size of a blueberry. . Both hemispheres of your baby's brain are growing, and her liver is churning out red blood cells until her bone marrow forms and takes over this role. She also has an appendix and a pancreas, which will eventually produce the hormone insulin to aid in digestion. A loop in your baby's growing intestines is bulging into her umbilical cord, which now has distinct blood vessels tocarry -
Week 8
New this week: Webbed fingers and toes are poking out from your baby's hands and feet, his eyelids practically cover his eyes, breathing tubes extend from his throat to the branches of his developing lungs, and his "tail" is just about gone. In his brain, nerve cells are branching out to connect with one another, forming primitive neural pathways. your baby — about the size of a kidney bean ..... -
Week 9
Your new resident is nearly an inch long — about the size of a grape . Your baby's heart finishes dividing into four chambers, and the valves start to form — as do her tiny teeth. The embryonic "tail" is completely gone. The placenta is developed enough now to take over most of the critical job of producing hormones. -
Week 10
Though he's barely the size of a kumquat — a little over an inch or so long, crown to bottom — and weighs less than a quarter of an ounce, your baby has now completed the most critical portion of his development. This is the beginning of the so-called fetal period, a time when the tissues and organs in his body rapidly grow and mature. Vital organs — including his kidneys, intestines, brain, and liver (now making red blood cells in place of the disappearing yolk sac) -
week 11
Your baby, just over 1 1/2 inches long and about the size of a fig, is now almost fully formed. She's already busy kicking and stretching, and her tiny movements are so effortless they look like water ballet. These movements will become more frequent as her body grows and becomes more developed and functional -
Weel 12
His intestines, which have grown so fast that they protrude into the umbilical cord, will start to move into his abdominal cavity about now, and his kidneys will begin excreting urine into his bladder. Meanwhile, nerve cells are multiplying rapidly, and in your baby's brain, synapses are forming furiously. From crown to rump, your baby-to-be is just over 2 inches long (about the size of a lime) and weighs half an ounce. -
Week 13
Fingerprints have formed on your baby's tiny fingertips, her veins and organs are clearly visible through her still-thin skin, and her body is starting to catch up with her head — which makes up just a third of her body size now. Your baby is almost 3 inches long (the size of a medium shrimp) and weighs nearly an ounce. -
week 14
His kidneys are producing urine, which he releases into the amniotic fluid around him — a process he'll keep up until birth. From head to bottom, he measures 3 1/2 inches — about the size of a lemon — and he weighs 1 1/2 ounces He's starting to develop an ultra-fine, downy covering of hair, called lanugo, all over his body. Your baby's liver starts making bile this week — a sign that it's doing its job right — and his spleen starts helping in the production of red blood cells -
Week 15
Your growing baby now measures about 4 inches long, crown to rump, and weighs in at about 2 1/2 ounces . She's busy moving amniotic fluid through her nose and upper respiratory tract, which helps the primitive air sacs in her lungs begin to develop. Although her eyelids are still fused shut, she can sense light. If you shine a flashlight at your tummy, for instance, she's likely to move away from the beam -
Week 16
he's about the size of an avocado: 4 1/2 inches long (head to rump) and 3 1/2 ounces. His legs are much more developed, his head is more erect than it has been, and his eyes have moved closer to the front of his head . -
Week 17
Your baby's skeleton is changing from soft cartilage to bone, and the umbilical cord — her lifeline to the placenta — is growing stronger and thicker. Your baby weighs 5 ounces now. She can move her joints, and her sweat glands are starting to develop......... -
Week 18
Head to rump, your baby is about 5 1/2 inches long. also he weighs almost 7 ounces.. His blood vessels are visible through his thin skin, and his ears are now in their final position, although they're still standing out from his head a bit. A protective covering of myelin is beginning to form around his nerves, a process that will continue for a year after he's born. -
Week 19
Her brain is designating specialized areas for smell, taste, hearing, vision, and touch. Your baby weighs about 8 1/2 ounces and measures 6 inches, head to bottom. Her kidneys continue to make urine and the hair on her scalp is sprouting. A waxy protective coating called the vernix caseosa is forming on her skin to prevent it from pickling in the amniotic fluid -
Week 20
Your baby weighs about 10 1/2 ounces now. He's also around 6 1/2 inches long from head to bottom and about 10 inches from head to heel. He's swallowing more these days, which is good practice for his digestive system. He's also producing meconium, a black, sticky by-product of digestion. -
Week 21
Your baby now weighs about three-quarters of a pound and is approximately 10 1/2 inches long . You may soon feel like she's practicing martial arts as her initial fluttering movements turn into full-fledged kicks and nudges -
Week 22
At 11 inches (the length of a spaghetti squash) and almost 1 pound, your baby is starting to look like a miniature newborn . His lips, eyelids, and eyebrows are becoming more distinct, and he's even developing tiny tooth buds beneath his gums. Inside his belly, his pancreas — essential for the production of some important hormones — is developing steadily -
Week 23
And now that she's more than 11 inches long and weighs just over a pound (about as much as a large mango), you may be able to see her squirm underneath your clothes. Blood vessels in her lungs are developing to prepare for breathing, and the sounds that your baby's increasingly keen ears pick up are preparing her for entry into the outside world.
