Trimester OneTrimester One

Corbyn, Whitney, Ashley, BrittanyCorbyn, Whitney, Ashley, Brittany

Week One & TwoWeek One & Two

-not actually pregnant the first week or two- sperm and egg unite in one of your fallopian tubes to form a zygote-zygote has 46 chromosomes - 23 from oocyte and 23 from sperm-amnion sac is formedWeek 3-Nervous system begins to develop-heart beating starts-At this point the baby is smaller then a pen point

Week Two

Week ThreeWeek Three

-Nervous system begins to -Nervous system begins to developdevelop-heart beating starts-heart beating starts-At this point the baby is -At this point the baby is smaller then a pen pointsmaller then a pen point

Week FourWeek Four Although you are as yet Although you are as yet

unaware that you are pregnant, unaware that you are pregnant, your baby is already your baby is already undergoing great changes. undergoing great changes.

The fertilized egg is now a The fertilized egg is now a quickly growing ball of cells quickly growing ball of cells called a blastocyst. called a blastocyst.

It is embedded more deeply in It is embedded more deeply in the uterine wall and the the uterine wall and the amniotic cavity is being amniotic cavity is being formed. formed.

The group of cells that will The group of cells that will make up the placenta is being make up the placenta is being organized and circulatory organized and circulatory networks containing maternal networks containing maternal blood are being formed.blood are being formed.

Three layers of cells are sorting Three layers of cells are sorting themselves out within the themselves out within the blastocyst. blastocyst. The ectoderm will form the The ectoderm will form the nervous system, hair and skin of nervous system, hair and skin of your baby. The endoderm will your baby. The endoderm will become the lining of the become the lining of the gastrointestinal tract, and various gastrointestinal tract, and various organs like the thyroid, liver and organs like the thyroid, liver and pancreas.pancreas.The mesoderm will develop into The mesoderm will develop into the skeleton, connective tissues, the skeleton, connective tissues, blood systems, urogenital system blood systems, urogenital system and most of the musclesand most of the muscles

Week Five

Your baby is now an embryo (so-called due to the little tail at the end of its developing spine) and is only barely visible to the naked eye. The spinal column, brain and heart have begun to develop. Baby is about 1/16th of an inch long

Week SixWeek Six The baby's heart has begun to beat! At The baby's heart has begun to beat! At

about ½ inch long your little one is the size about ½ inch long your little one is the size of your little fingernail.of your little fingernail.

He has begun to grow buds where his arms He has begun to grow buds where his arms and legs will be and his head has the and legs will be and his head has the beginnings of eyes, ears and a mouth. beginnings of eyes, ears and a mouth. Starting prenatal care now is essential. For Starting prenatal care now is essential. For the next four weeks your baby will be most the next four weeks your baby will be most vulnerable to factors that can interfere with vulnerable to factors that can interfere with proper development. proper development.

Now is the time, if you haven't already, to Now is the time, if you haven't already, to stop smoking, drinking or indulging in stop smoking, drinking or indulging in recreational drugs. Also, be particularly recreational drugs. Also, be particularly sensitive to environmental risks such as sensitive to environmental risks such as exposure to chemicals, tobacco smoke and exposure to chemicals, tobacco smoke and animal diseases; some of which, animal diseases; some of which, toxoplasmosis for instance, can be toxoplasmosis for instance, can be contracted by humans contracted by humans

Week SevenWeek Seven The baby's heart is now beating The baby's heart is now beating

regularly at 150 beats per minute. regularly at 150 beats per minute. The arm buds have grown and now The arm buds have grown and now

the hands are beginning to the hands are beginning to develop.develop.

The whole baby is still only 1/3 of The whole baby is still only 1/3 of an inch long, but the brain, an inch long, but the brain, intestines, pituitary gland and intestines, pituitary gland and pancreas are growing. pancreas are growing.

Though the genital tubercle is Though the genital tubercle is present, you can't tell by looking present, you can't tell by looking whether it is a girl or a boy, yet. whether it is a girl or a boy, yet.

The baby's face is developing The baby's face is developing rapidly, the nasal pits have formed, rapidly, the nasal pits have formed, the ears are developing and there the ears are developing and there are developing lenses on the eyes. are developing lenses on the eyes.

Week EightWeek Eight

Your baby is now about 10,000 Your baby is now about 10,000 times bigger that it was at times bigger that it was at conception but is still only about conception but is still only about an inch long. an inch long.

This week the baby's gonads will This week the baby's gonads will either become testes or ovaries. either become testes or ovaries. The eyes are formed and The eyes are formed and covered by a fold of skin, though covered by a fold of skin, though the eyelid will not open yet. the eyelid will not open yet.

The arms and legs are growing The arms and legs are growing longer and the arms are bent at longer and the arms are bent at the elbow, allowing the baby to the elbow, allowing the baby to hug herself. The tip of the nose is hug herself. The tip of the nose is now visible and teeth are forming now visible and teeth are forming under the baby's gums.under the baby's gums.

Your little one is beginning to Your little one is beginning to move around now and kick his move around now and kick his legs, but he is still way too small legs, but he is still way too small for you to feel it. for you to feel it.

Week NineWeek Nine The baby officially changes The baby officially changes

from being an embryo to a from being an embryo to a fetus this week. This is mostly fetus this week. This is mostly due to the fact that his little due to the fact that his little embryonic tail has embryonic tail has disappeared. disappeared.

Bones and cartilage are Bones and cartilage are beginning to form. beginning to form.

The umbilical cord and The umbilical cord and placenta are forming and placenta are forming and growing. growing.

If touched from the outside of If touched from the outside of the uterus, the baby will the uterus, the baby will respond by moving. The respond by moving. The fingers have formed but are fingers have formed but are webbed. webbed.

Fact: at the end of this week the babies arms are the length of this printed 1

Week Ten

• Most of the baby's joints are formed now-shoulders, elbows, wrist, hands and fingers, knees, ankles, feet and toes. All of his organs are present and accounted for, but not fully formed or functional. Your little one is now about as long as a paper clip and weighs the same as four paperclips, in other words: 1 ¾ inch and ¼ oz.

Week ElevenWeek Eleven

Your baby's little Your baby's little fingers are growing fingers are growing nails now. The baby nails now. The baby probably will double probably will double his length this week. his length this week. The irises of your The irises of your baby's eyes are baby's eyes are developing now. developing now.

Week TwelveWeek Twelve

The baby's chest is rising The baby's chest is rising and falling as it practices and falling as it practices breathing movements..breathing movements..

With kidneys that are fully With kidneys that are fully functioning the baby can functioning the baby can swallow amniotic fluid and swallow amniotic fluid and excrete it as urine. excrete it as urine.

The amniotic fluid is The amniotic fluid is completely replaced every 3 completely replaced every 3 hours, so the baby's hours, so the baby's environment stays fresh. environment stays fresh. Even though she is not Even though she is not eating yet, the baby's eating yet, the baby's intestines are contracting in intestines are contracting in peristaltic movements as if peristaltic movements as if she were digesting food she were digesting food

Teratogen Teratogen ~Thalidomide ~Thalidomide

--This drug was used to This drug was used to control nausea control nausea during pregnancyduring pregnancy

-Thalidomide was used -Thalidomide was used in the late fifties and in the late fifties and removed from the removed from the market in 1961market in 1961

-Thalidomide causes -Thalidomide causes deformities in the deformities in the developing fetus.developing fetus.

--Deformities such as Deformities such as defective defective intestines, hearing intestines, hearing defects or no ears defects or no ears at all, and impaired at all, and impaired vision.vision.

-Many of the -Many of the foetuses were born foetuses were born with undeveloped with undeveloped limbs or no limbs limbs or no limbs at all.at all.

~Radiation~Radiation There are a number of ways to There are a number of ways to

be exposed to radiation: having be exposed to radiation: having a medical X-ray, working at a a medical X-ray, working at a nuclear power plant, working in nuclear power plant, working in any industrial setting where X-any industrial setting where X-rays or with other radioactive rays or with other radioactive substances. Countless other substances. Countless other minor sources such as TVs, minor sources such as TVs, smoke detectors, and airplane smoke detectors, and airplane trips. Radiation exposure at trips. Radiation exposure at high enough levels can cause high enough levels can cause developmental risks to a developmental risks to a developing fetus like a developing fetus like a reduction in height, severe reduction in height, severe mental retardation, small head mental retardation, small head size, impaired brain size, impaired brain development, childhood development, childhood leukemia, and cancer in later leukemia, and cancer in later life. life.