Prenatal Development

Weeks 1-40

ConceptionO Ovum: female cell or eggO Uterus: organ in a woman’s body in

which the baby developsO Sperm: male cellO Conception: when the ovum and the

sperm uniteO Ovum lives up to 24 hours after release

from ovaryO Sperm lives up to 72 hours after release

from male

Week 1 O The first week is your menstrual

period. O Your pregnancy will be dated from

this:O Most women don't know the precise

moment they have ovulated or conceived.

O Most do remember the first day of their last menstrual period.

Week 2 O The very end of the second week

marks the release of the egg—ovulation

O At this point in your cycle, your uterine lining is developing under the influence of hormone your body secretes to make it receptive to the fertilized egg.

Week 3

O Right between weeks two and three (about day 14 of a 28-day cycle) an egg will be released into your fallopian tube—this is called "ovulation."

O Some women can tell when they ovulate by noting mild cramping or pain or increased vaginal discharge.

O Once the egg has been released, it must be fertilized for you to become pregnant.

O The egg is fertilized early in the third week and typically implants in the uterus 6-12 days after ovulation.

Stages of the Zygote O Zygote is the fertilized eggO Cells will divide at rapid rateO Within 5 days there will be over 500

cells.O Travels down fallopian tube and

attaches to uterusO This stage last only 2 weeksO About the size of a pin head.

Stage of the EmbryoO Lasts from the time the cells attach

to uterus to week 12. O Embryo: ball of rapidly multiplying

cellsO Almost all of the internal organs

begin to develop during this six-week stage

O Embryo also becomes enclosed in a fluid-filled pouch called the amniotic sac.

Embryo Key TermsO Placenta: tissue connecting the

embryo to the uterine wall.O Umbilical cord: attaches the embryo

the the placenta.O Amniotic fluid: fluid inside amniotic

sac. Protects the developing baby from falls that a mother might have.

Week 4O The fertilized egg is a fluid-filled cluster of rapidly multiplying cells. O The egg tunnels into the uterus where it promptly divides into two

parts. O Half the egg attaches to the uterine wall and develops into the

placentaO will transport oxygen and nutrients to your babyO Transports waste products away from your little

O The other half will develop into the embryo, which will later become the fetus.

O During this week the following occurs:O Spinal cord development. A sheet of cells on the back of the embryo

folds in the middle to form a tube that will become the baby's spinal cord.

O Brain section development. At the other end, the tube enlarges to form the brain's major sections.

O What's happening with youO Pregnancy symptomsO Missed period and possible spotting

Week 5 Your baby’s

growth: Embryo cell layers

What’s happening with you.

O Just a bit bigger than an apple seed. O Embryo' has already divided into

three layersO The top layer: Neural folds create

a tube which will form the front part of brain, the heart which will beat this week, and the spinal cord and back bone

O The middle layer. These cells will produce the circulatory system, bones, most muscles, cartilage, sex organs and kidneys.

O The bottom layer. These cells will form the lungs, intestines and beginnings of the urinary system.

O Missed period. You should have missed your period or have experienced slight spotting.

O Pregnancy symptoms. As your blood flow works to catch up with your rapidly expanding circulatory system, you may experience morning sickness (nausea), and fatigue.

O Unappetizing smells and tastes. It may help to avoid foods with very strong smells or tastes, such as oily or fried foods and spicy dishes. Even strong-smelling cleaners and disinfectants may bother you right now.

O If you aren't experiencing these symptoms, don't be concerned. You may be one of the lucky moms who sail through early pregnancy without feeling nauseous at all.

Week 6Your baby’s growth Your body

O About the size of a kidney bean.

O Developing this week:O Eye retina is formingO Neural tube O HeartO LimbsO BrainO Larynx and inner earO Neck and lower jawO Facial featuresO OrgansO Placenta

O Breast changes. O Become larger and more

sensitive. O Tingling sensations O Areola may start to darken.

O Weight change.O May have gained two or three

pounds.. O Morning sickness.

O May get worse this week as your hormone levels rise.

O Perfectly normal for nausea to appear at any point of the day or night.

Week 7 Your baby’s

growth Your body O About 1 inch long. O Fetal digestive system is beginning

to develop. The umbilical cord, has started taking shape. This ropelike cord contains two arteries and a vein. It brings oxygen and nutrients to the embryo and carries away waste products.

O Facial featuresO EarsO EyesO Head O HeartO AirwaysO MouthO Skin

O Weight gainO Morning sicknessO More bathroom

breaksO Increased energy

Week 8 Your baby’s

growth Your body O Head will become more rounded as

the embryo begins to look more like a baby.

O Body begins to fine-tune its bone, joint and limb development, and tiny finger and toe buds appear.

O Eyelids are formingO NoseO Blood beginning to flowO Digestive tract continues to developO Gonads transform into either testes or

ovariesO EarsO ElbowsO VertebraeO MusclesO Skin

O Rollercoaster of emotions

O Breast enlargement and bigger waistline

O CrampingO First doctor’s visit

Week 9Your baby’s

growth Your body O About the size of a peapod and

weighs a little less than half an ounce.

O Muscles, nerves and organs are forming.

O Genitals are beginning to develop, but it's still almost impossible to tell on ultrasound whether you're going to have a boy or a girl.

O Increased body growthO DigitsO Digestive system O EyelidsO EarsO Brain

O Increased blood volume

O FatigueO Testing

O CVSO Amniocentesis

Week 10

Baby’s growth Your body O TeethO Reproductive organsO Nervous systemO Internal organsO IntestinesO Taste budsO EyelidsO Upper lipO Joints

O Still in regular clothes

O Fatigue and nausea

Week 11

Baby’s growth Your bodyO FingernailsO EarsO GenitaliaO SwallowO KickO BonesO Brain nerve cells connectingO All major organs will be fully

developedO Spinal nervesO Heartbeat

O Uterus expansion O Waist growthO Skin changes:

dark line on abdomen

O Hair and nail changes

Week 12

Baby’s growth Your body O Had developed a facial

profileO KidneysO PancreasO LiverO Digestive processO BrainO Pituitary gland with begin to

produce hormonesO Hair (lanugo) will appear all

over the body

O Uterus enlargement

O Skin radianceO Skin problemsO Nausea and

fatigue goes awayO Weight gain

Congrats!O You have concluded the 1st trimester!O All body parts are in place, it will just

continue to grow.

Stage of the Fetus O 3rd and final stage of prenatal

development O Weeks 9-40O Unborn child is called fetusO Body, head, arms, and legs grow

rapidlyO Organs continue to develop for blood

circulation, breathing, and digestion