CONCEPTION
Traditionally, conception occurs when a sperm cell and an egg cell unite inside the fallopian tube of the reproductive tract of a female.
Classically, sperm and egg cells unite their 23 chromosomes into a total of 46 chromosomes.* 23 chromosomes from father and 23 chromosomes from mother combine to create a unique individual (identical multiples are an exception!). *certain conditions exist that are exceptions. Trimesters Growth and development of your preborn baby in the first trimester lay foundations for the entire body. Normal full term pregnancy is divided into three trimesters. 36 hours after conception One fertilized egg cell has divided into two cells. 48 hours after conception Two cells have divided into four. 72 hours after conception 16 cells have divided into 32 cells. Most don’t even know they are pregnant. 4 days after conception 60 to 70 cells are now called a morula. 5 days after conception Cells move to one side, forming an embryonic disk called a blastoderm. The blastoderm becomes a preborn baby. All other cells develop into amniotic membranes and the placenta. Blastoderm layers The outer layer develops into: Brain Spinal cord All nerves All sensory organs including the skin. The inner layer of the blastoderm develops into the lining of the entire digestive tract, including the: Pharynx Esophagus Stomach Liver Intestines Anus Later a third layer develops and becomes the skeleton, muscles, and many internal organs. Now called an embryo, a preborn baby is not implanted in the womb (uterus) yet! 11 – 12 days after conception An embryo is developing his or her: Heart Nervous system Spinal cord WEEK 4 36 days after conception Arm buds are formed. Leg buds are formed. All muscle blocks have appeared. 38 days after conception Eye muscles are forming. Upper and lower jaws fuse mid-line of the face. Hand plates (paddle-like beginnings of hands) develop. 42 days after conception Earliest reflexes begin. 44 days after conception Nerve cells of the retina of the eye are forming. Jaw parts continue to fuse and grow. Palate of the mouth is forming. Semicircular canals of the ear (aid in maintaining balance) are forming. 50 Days after conception Your preborn baby moves a lot now. The head is very large and bent over the bulging heart. Hands are now far apart. Bone continues to replace cartilage. Neck muscles are forming. The clitoris appears in the female. Ovaries descend in the female. Testes begin to descend within the body of the male. Kidneys develop tubules, which will function throughout life. WEEK 8 The anal membrane ruptures to form the anus. Some major muscles are well formed and movements are possible. The head grows quickly because the brain develops so early. Kidneys are maturing. Stomach moves into its final position. Layers of muscle in the esophagus, stomach, and intestines grow rapidly. Major blood vessels of the body are complete. Arms and legs are growing rapidly. A preborn baby will often touch his or her face. Eyes are in their normal place. Jaws are still forming. Palate of the roof of the mouth is forming. Taste buds take form. Endocrine glands are forming: Thyroid Thymus Adrenals. Lungs have lobes and many minute tubes. A diaphragm begins to separate the heart and lungs from the intestines. Hands and feet are well formed. Mammary glands can be identified. The umbilical cord contains three large visible blood vessels. 9 weeks after conception Your preborn baby’s back is straighter. His or her head is no longer bending toward the chest. Toenails and fingernails are forming. Hair follicles are forming. Eyes appear to be developed. Iris diaphragm and eyelids are formed. Eyelids will stay shut for the next three (3) months. Ears are low on the head. Teeth are beginning to form. Skeleton and all muscles are rapidly forming. Kidneys begin to function, secreting small amounts of urine into the amniotic fluid. Metabolic waste products are exchanged through the placenta to be picked up and eliminated by mother’s body. Females begin to develop: bladder uterus vagina 10 Weeks after conception Your preborn baby’s ears are now higher on the head. Eyes have moved forward. The basic divisions of the brain are complete. Connections between the nerves and muscles increase. The upper part of the mouth (palate) forms by two bony plates fusing together. Cleft palate occurs at 10 weeks after conception if the two bony plates do not fuse together. Bones are forming in toes, fingers, and other places. Lungs and gall bladder are complete. 11 Weeks after conception Tooth buds appear for all 20 baby teeth. Sockets for these teeth develop in the jaw. 10 tooth buds grow in each jaw. Vocal cords of the voice box (larynx) form. Thymus and thyroid glands continue developing. Trachea, lungs, stomach, liver, pancreas, and intestines all rapidly develop into their final states. The liver temporarily makes blood cells. Ductless glands within the pancreas begin to form insulin. The lining of the intestine forms microscopic folds and mucus to help digest foods later. WEEK 12 Your preborn baby’s swallowing and sucking reflexes are better developed. Taste buds are numerous. Digestive glands are formed and could function. Salivary glands form. Vocal cords are complete. Ribs and vertebrae form by ossification of cartilage. Both males and females now have milk glands that are capable of secreting a milky substance. 12 weeks gestational age, your preborn baby now measures 3 inches from head to rump and weighs ½ an ounce. The Second Trimester Rapid Growth and Activity During the second trimester, your preborn baby, the placenta, uterus, and blood volume are bigger than during the first trimester. The demands of pregnancy on your body are greater than during the first trimester. Month 4 Your preborn baby’s face is becoming more refined. Eyes are still shut yet are sensitive to light. Lips have formed on the mouth. Skin is loose, thin, and wrinkled. Skin appears pink or red from underlying blood vessels. Tips of fingers and palms develop “touch pads.” Toes and soles of feet develop “touch pads.” Females further develop reproductive organs and cells. All egg cells develop before birth. Your preborn baby’s heart circulates 25 quarts of blood per day. Lungs are inactive. The brain’s foundation is all there. The brain doesn’t reach structural completion until some time after birth. Month 5 Both girl and boy preborn babies develop pink nipples equipped with milk ducts. Much of the skeleton is bony hard. Fingernails are forming (then toenails form). Fine, downy hair (lanugo) covers the body. Vernix covers the body. Sweat glands are forming. You may begin to feel your preborn baby’s movements during the 5th month of pregnancy. Pregnant mothers who’ve already given birth may feel preborn baby’s movement before the 5th month of pregnancy. Loud noises and sudden sounds can cause your preborn baby to move. Your preborn baby’s sleep patterns may now be recognized. Your preborn baby grows and develops at a very rapid rate. Month 6 Your preborn baby’s intestines lower into the pelvic basin. Vernix is very thick. Little or no fatty deposits are under the skin. Bones continue to calcify. Spinal column is developing: 33 rings 150 joints 1,000 ligaments Your preborn baby swallows amniotic fluid and urinates into amniotic fluid. Amniotic fluid is sterile. Meconium (preborn baby’s first bowel movement) accumulates in the intestine. Your preborn baby may suck his or her fingers. Your preborn baby’s eyes open during the 6th month of pregnancy. The Third Trimester Month 7 Some of the lanugo disappears. The brain is growing very rapidly, developing the centers controlling: Hearing Sight Smell Speech Walking Areas that control all muscular movement. Testes descend into the scrotum of boy preborn babies. Your preborn baby’s heartbeat can be heard easier now. Month 8 Your preborn baby is sensitive to sounds of: Knocks Music Voices Other noises Fatty layers are deposited under skin. Nutrients are being stored for reserve to use after birth. Your preborn baby may get hiccups! Month 9 While living in amniotic fluid, vernix protects your baby’s skin. Your preborn baby looses some of the vernix covering his or her body. Inside your preborn baby’s mouth, his or her gums are ridged. Tooth buds are beneath the ridges of your preborn baby’s gums. Meconium (baby’s first bowel movement) accumulates in the intestines of your preborn baby. Fingernails and toenails have grown long. Your preborn baby is developed enough to live outside your body! |
Thank you for donatingPayPal is safe and secure
Eat to meet the nutritional demands of your growing uterus, the growth and development of the placenta, and the growth and development of your preborn baby. Braxton Hicks contractions commonly start in the second trimester of pregnancy. |