NAME ___________________________________________________________ PERIOD _________________________
FERTILIZATION AND PREGNANCY
Deciding to Become a Parent
 Physical health and age
 Financial circumstances
o From birth to 18 years old costs $250,000
 Relationship with your partner
 Education, career and child care plans
 Emotional readiness
 Social support
 Personal qualities
 Philosophical or religious beliefs
Preconception Care
 Preexisting medical conditions?
 Prescription drug/OTC drug use?
 Prior pregnancy or delivery problems?
 Age?
 Smoking, alcohol or other drug usage?
 Any infections?
 Diet?
 Family history of genetic disorders?
Female Terms to Know
 Ovum – egg
 Ovary – produce eggs and sex hormones
o Thousands of egg cells are stored here
 Follicle – saclike structure within the ovary where the eggs mature
 Fallopian Tube – (Oviduct) where egg travels from ovary to the uterus; the site of fertilization
 Uterus – where egg attaches and develops
 Endometrium – inner lining of the uterus
 Vagina – opening to the uterus
 Zygote – fertilized egg
Male Terms to Know
 Testicles/Testes – produce hormones and sperm cells
o About 1,000 tubules where sperm are produced
o 100 million sperm are produced
 Scrotum – the sack that holds the testes
 Epidydimus – tube where sperm are held inside the testes
 Vas Deferens – tube that opens into the urethra inside the penis
 Prostate Gland and Cowper’s Gland – produce a mixture of fluids called semen
 Testosterone – hormone that stimulates male sexual characteristics
Understanding Fertility
 Conception involves the fertilization of a women’s egg by a man’s sperm
 Each month a women’s ovaries release an egg
 It takes approximately 3-4 days for the egg to travel through the fallopian tube
 Eggs alternate between the two fallopian tubes each month
 The egg continues to travel into the uterus and out the cervix and vagina.
o This is called Ovulation
Fertility
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If the woman has intercourse during ovulation:
During a man’s ejaculation millions of sperm travel into the woman’s vagina, into the cervix and uterus
The sperm continue into the woman’s fallopian tube to meet the egg
Only one of those sperm can permeate the woman’s egg
o The sperm meets the egg in the fallopian tube
o The sperm releases an enzyme that does not allow any other sperm to permeate the egg also
 If the sperm permeates the woman’s egg Fertilization takes place.
Development
 As soon as fertilization occurs, the zygote starts to undergo cell division that begins the growth process.
 It continues to divide as it travels through the fallopian tube and to the uterus.
 Upon reaching the uterus, the cluster of cells now known as a blastocyst becomes implanted in the
endometrium (lining of the uterus).
o This is where the eventual fetus will develop until birth
Genetics
 The ovum (egg) carries the hereditary characteristics of the mother and her ancestors; the sperm carries those
from the father and his ancestors.
 Each egg and sperm contain 23 chromosomes, each of which contains genes.
 The fertilized egg or zygote will contain all 46 chromosomes
Twins or Multiples?
 The usual course of events is that one egg and one sperm unite to produce one fertilized egg and one baby.
 Fraternal Twins - If the ovaries release two (or more) eggs during ovulation and if both eggs are fertilized, twins
will develop.
 Identical Twins – If the fertilized egg divides into two cells that develop separately, shared genetic material will
be split, twins will grow and develop.
Pregnancy
 13 week trimesters for 38 total weeks or 266 days
 Early Tests
o Can be performed as early as 2 weeks after fertilization
o Home pregnancy kits sold OTC include a small sample of red blood cells called Human chorionic
gonadotropin (HCG)
o Woman adds a small amount of her urine
o Instructions must be followed carefully
Fetal Development
 First Trimester
o Blastocyst – for first 2 weeks
 Inner cells divide into three layers
 One layer – inner body parts
 Middle layer – muscle, bone, blood, kidneys, and sex glands
 Third layer – skin, hair, and nervous tissue
o Embryo – At end of second week
 All major body structures are formed between 2nd and 9th week
o Fetus - At 2nd Month
Early Signs and Symptoms
 Missed menstrual period
 Softening of the uterus
o Hegar’s sign found during pelvic exam
 Slight bleeding
 Nausea
 Breast tenderness
 Increased urination
 Sleepiness, fatigue and emotional upset
Fetal Development
 Placenta
o Network of blood vessels called chorionic villi
o Allows a 2-way exchange of nutrients and waste materials between the mother and fetus
o Brings oxygen and nutrients to the fetus and transports waste products out
o Does not provide a perfect barrier between fetal and maternal circulation
 Some blood cells are exchanged and certain substances such as alcohol pass freely from
maternal circulation through placenta to the fetus
 Umbilical cord
o The cord connecting the placenta and fetus, through which nutrients pass
 Amniotic sac
o A membranous pouch enclosing and protecting the fetus, containing amniotic fluid
Fetal Development
 Second Trimester
o Fetus grows to about 14 inches and 2 pounds
 Third Trimester
o Fetus gains protective fat layers, Respiratory and Digestive organs develop