Conception and Pregnancy

http://www.youtube.com/watch?v=Cr45f2OjC5U&list=PL676C9F52251404E4

Fertilization

Sperm + ova = zygoteOvum can be fertilized over a

maximum range of 72 hours each menstrual cycle.

Estimated that 30% of all fertilized oval naturally do not survive.

Fertilization begins when:The head of one sperm enters

ovum.Occurs in outer 1/3 of fall. Tube.Fertilized ovum is called a zygote.

One cell, one nucleus, all the necessary ingredients for its development.

In Vitro Fertilization

1st attempted in 1978Ovum retrieved by laparoscope,

mixed with semen in a test tube.Returned to uterus after 2 ½ days50% success rate of fertilization20-30% implant rate of those

fertilized.

http://www.youtube.com/watch?v=7FHLPi5YCz0

Cell Division

It is called cleavage.Bulk of cell does not change.Rapidly dividing cell ball

develops: blastocystPassage to uterus takes 7-9 days.

Embryo Stage: Begins the 2nd week and extends

through the 8th week.

Fetal Stage:After the 8th week, until birth.

BlastocystFluid filled hollow ball of cellsBurrows little finger-like projections

called villi into the blood supply of the endometrium.

Outer rim becomes the chorion (fetal membrane).

Cells near the outer rim become the embryo.

Placenta

Develops by 3 monthsTakes over job of providing

nourishment for the fetus and carrying fetal waste to the maternal blood.

Joined to fetus by umbilical cordBegins to secrete estrogen and

progesterone.

Approximately 8 in. in diameter, 1 in. thick, and about 1/6 of fetal wt.

Transfer of nourishment and waste occurs by osmosis

Calcium, phosphorous, amino acids, glucose, fats, bacteria, viruses, antibodies pass from maternal side to fetal side.

NO intermixing of maternal blood and fetal blood.

O2 and CO2 pass through by diffusion

Prevents passage of some but not all harmful substances into fetus.

Nicotine, alcohol, most drugs pass through placental barrier and harm the fetus.

Umbilical cord: 1 umbilical vein, 2 umbilical arteries, Wharton’s jelly enclosed in a membrane.

Cords are examined at birth for completeness.

Birth

At birth, lung function is established.

Umbilical vein and arteries become fibrous cords.

Once cord is cut, large amount of blood returns to the heart from the lungs.

Also at birth, the foramen ovale closes due to equalization of pressure in the atria, and normal circulation begins.

Gestation is the period of development of the child in the mother’s uterus. Lasts approximately 280 days.

Pregnancy is described in terms of the number of weeks of gestation (40 total), or it may be divided into three trimesters of 3 months each.

The due date, or estimated date of confinement (EDC), is calculated from the first day of the last menstrual period (LMP).

A fetus is viable when it is capable of living outside of the mother. It depends on the developmental age, birth wt, and developmental stage of the lungs.

The amnion, also known as the amniotic sac, is the innermost of the membranes that surround the embryo in the uterus and form the amniotic cavity.

Amniotic fluid is the liquid in which the fetus floats and is protected.

Amniocentesis is a surgical procedure in which a needle is inserted through the abdominal and uterine walls to obtain a specimen of amniotic fluid.

Done after 16th week of pregnancy, is used to evaluate fetal health and diagnose certain congenital disorders.

Abruptio Placentae:An abnormal condition in

which the placenta separates from the uterine wall prematurely before the birth of the infant.

Placenta previa:The abnormal implantation of the

placenta in the lower portion of the uterus. Symptoms include painless sudden-onset bleeding during the third trimester. Treatment ranges from bed rest to immediate delivery by C-section.

Pregnancy:Physiological Changes

Hegar’s sign: softening of the lower part of the uterus; about the 6th week.

Goodell’s sign: cervix softening

Chadwick’s sign: tissue around the vagina becomes thicker, softer, and takes on a bluish, purple color.

Braxton-Hicks contractions: painless, intermittent contractions of the uterus, caused by enlargement.

Ballottement: rebounding of the floating fetus in the uterus when the fetus is lightly tapped during a vaginal exam; after the 4th month.

Signs and Symptoms

Skin:Linea nigra; dark line from

umbilicus to mons pubisChloasma: a dark freckle-like

pigmentation of the faceStriae gravidarum: white streaks

on breasts, abdomen, thighs.

Cessation of mensesUrinary frequencyMorning sicknessQuickening: 1st sensation of fetal

movement, around 4th monthBreasts: fuller, larger, tender.Fetal heartbeat: heard 3rd month

with fetone

Ultrasound: sound waves that scan the abdomen to identify outline of baby and placenta.

Souffle: soft murmur produced by blood flow in the placenta and umbilical arteries.

Labor and Delivery:Engagement and Lightening

Final 2 – 4 weeks of gestationFetal head sinks into pelvis

(engagement)Effects on mother (lightening):Fundus lowers, upper abdomen

flattens, breathing easier; walking more difficult.

Onset of Labor

The “Show” – mucus streaked with blood from cervix

Rupture of waters: amniotic sac tears and releases amniotic fluid

Labor pains: regular contractions of the uterus.

True Labor

Characterized by rhythmic, increasingly intense uterine contractions

Cervix changes shape:Effacement: shorteningDilation: widening

Crowning: fetal head presents and can be seen

Presentation: manner in which the fetus presents itself in the vagina

Cephalic presentation: head firstBreech presentation: buttocks or

legs first

Discussion

Suctioning of infant immediately upon delivery

Cry: present or absent; weak or strong

Apgar Score

An evaluation of a newborn infant’s physical status by assigning numerical values (0 to 2) to each of five criteria:

Heart rateRespiratory effortMuscle toneResponse stimulationSkin colorThe newborn is evaluated at 1

and 5 minutes after birth.

A total Apgar score of 8 to 10 indicates the best possible condition.

http://www.youtube.com/watch?v=7U2z7WMthZ0

Diseases and Disorders

Dysmenorrhea:Painful spasms of uterine

muscles.Amenorrhea:Absence of normal menstruation

due to hormone imbalance, pregnancy, wt. loss, menopause.

PMS:Premenstrual Syndrome;

irritability, fatigue, nervousness, depression, cause unknown.

PID:Pelvic Inflammatory Disease; can

cause salpingitis, oophoritis.

Vaginitis:Usually yeast infections (Candida)Causes leukorrhea (white

discharge); can be viral, bacterial, fungal, protozoan;

Causes thick discharge, mild pain on urination, itching.

Treatment: metronidazole

Myoma:Fibroma / fibroids; benign tumors

of the smooth muscleOvarian cysts:Fluid filled sac that develops from

a follicle that fails to rupture completely

Endometriosis:Displaced endometrial tissue,

usually on the peritoneum of the abdomen

Cancer:Ovaries, breast, uterus, cervix

(Pap smear).Testicular, prostate (PSA test)

Hermaphrodite:Has both testicular and ovarian

tissue; rare in humans, more common in other species.

Klinefelter’s Syndrome:XXY (47); male with small testes,

gynecomastia, subnormal intelligence; occurs in 1:700 live births.

Turner’s Syndrome:XO (45); female, poorly

developed gonads, short stature, impaired intelligence, ovaries fail to respond to FSH, LH stimulation.

STD’s http://

www.youtube.com/watch?v=ARe5tEpb99s

Fact or Myth?

Gonorrhea

Bacteria spread by genital contact as well as contact with anal and pharyngeal mucosal surfaces.

Males: painful urination & discharge of pus.

Females: lower abdominal discomfort, vaginal discharge, abnormal bleeding.

Gonorrhea

Treated with antibiotics.

Syphilis

Caused by bacteriaCauses ulcers (chancres) on

penis and in vagina.Secondary signs: pink rash over

body, fever, joint pain.

Syphilis

Tertiary signs: destructive lesions of CNS; blood vessels, bones, skin.

Treated with penicillin (PCN).

Chlamydia

Most common STDVaginal discharge or burning

abdominal, rectal, or testicular pain

Painful intercourse and irregular menses.

Genital Herpes

May remain silent for weeks or years.

Blister-like lesionsCongenital herpes can cause

severe malformation of fetusCan lead to cervical cancerIncurable!!!!

Genital Warts

Viral; common skin wart on genitals.

Caused by papilloma virusTreatment: chemical or physical

removalCan lead to cervical cancerIncurable!!!!

Hepatitis B

ViralIncurableImmunization available

AIDS

Acquired Immunodeficiency Syndrome

Viral; caused by HIV Early: wt. loss, frequent fevers,

mild infections, weakness, enlarged lymph glands

AIDS

Later: susceptibility to common infections, pneumonia, cancer.

Treatment: antivirals, immunostimulants to slow progress of virus

Incurable!!!!

Non-gonococcal Urethritis

Bacterial infectionThin, clear discharge from penis

or vagina, mild pain during urination

Pubic Lice

Cause: louseItching in region of pubic hairTreatment: creams, lotions, or

shampoos containing gamma benzene hexachloride