Pregnancy

Question 1

Fertilization

Answer 1

100% of sperm delivered to vagina 
3% survive to cervix 
0.1% survive to uterus 
0.001% survive to oviducts 
Oviducts is the site of fertilization

Question 2

Implantation of blastocyst

Answer 2

Implants at 7-10 days

Question 3

Summary of events from ovulation and fertilization to implantation

Answer 3

1 day after LH peak = ovulation in the ovary
2 days after LH peak= fertilization in the Fallopian tube
2-4 days after LH peak = cell division to ~32 cells in the Fallopian tube
5 days after LH peak = blastocyst enters the uterine cavity
6-7 days after LH peak = implantation in the uterus
9-10 days after LH peak = human chorionic gonadotropin (hCG) from implanted blastocyst (trophoblast cells) rescues corpus luteum, location = trophoblast -> maternal ovary

Question 4

Development

Answer 4

After implantation =
Placenta develops
Gas and nutrient exchange
Endocrine organ secreting essential pregnancy hormones (hCG) maintains corpus luteum until placenta takes over at 3 months

Question 5

Gestation

Answer 5

Pregnancy
About 38 weeks from conception
Physical changes within mom =
Uterine enlargement
Breasts enlarge and develop ability to produce milk
Volume of blood increases 30%
Weight gain
Respiratory activity increases by about 20%
Urinary output increases
Kidneys excrete additional wastes from fetus
Nutritional requirements increase

Question 6

Fetal development

Answer 6

Embryo phase = weeks 1-8, development of all systems, 23 Carnegie stages, most susceptible
Fetal stage = weeks 9-36, growth, continued differentiation of organs and tissues

Question 7

4 weeks gestation

Answer 7

Somites are forming (spinal cord)

Ear and eye start to form

Question 8

5 weeks gestation

Answer 8

3 weeks since implant and missed period 
Heart is beating 
Placenta is fully operational 
Mouth, liver, kidney, digestive systems
Arm and leg buds

Question 9

7 weeks gestation

Answer 9

13-17mm
Foot and hand rays
Muscle development

Question 10

8 weeks gestation

Answer 10

23-28mm 
Genitalia differentiate (external)
Bones start to ossify 
Rays separate into toes and fingers 
First trimester is the main period of organogenesis 
Second and third trimesters = growth

Question 11

12 weeks

Answer 11

Bone ossification continues 
6-9cm long 
Smiling
Sucking
Frowning 
Has bones, skin, and hair 
Kicking and moving 
Hormone secretion

Question 12

16 weeks

Answer 12

Grasping
Reacts to sounds
Kicks can be felt

Question 13

20 weeks

Answer 13

Scalp hair
Lung development
Can survive outside womb at 24 weeks

Question 14

Parturition (stages of labour)

Answer 14

Cervical dilation = higher oxytocin, longest stage, 2-24hours
Delivery of baby = cervical dilation and effacement is complete, last 30-90minutes
Delivery of placenta = uterine contractions separates placenta form uterine wall, usually within 15-30minutes after baby is born
After delivery uterus shrinks to presentational size (involutional)

Question 15

Etopic pregnancy

Answer 15

Ovum attaches outside uterus
Usually happens in Fallopian tubes
Symptoms = acute pelvic pain, vaginal bleeding
Pregnancy termination

Question 16

Spontaneous abortion

Answer 16

Aka miscarriage
Natural termination before fetus is viable
Symptoms = vaginal bleeding, cramping and pelvic pain
D and C

Question 17

Hypremesis gravidarum

Answer 17

Excessive vomiting during pregnancy
Treatment = IV fluids or oral fluids
Second pregnancy better

Question 18

Toxaemia (pre-eclampsia)

Answer 18

Third trimester
Symptoms = hypertension, sudden weight gain, proteinuria, edema in face, hands, and feet
Treatment = frequent monitoring, delivery

Question 19

Abruptio placentae

Answer 19

Separation of placenta from uterus
Partial separation = may be asymptomatic
Complete separation = severe abdominal pain, vaginal bleeding, shock, decreased fetal heart tones
Delivery

Question 20

Placenta Previa

Answer 20

Placenta in lower uterus (near or over cervix) 
Symptoms = bright red vaginal bleeding 
Third trimester 
Vaginal delivery if mild 
C-section if severe

Question 21

Division errors

Answer 21

Identical twins = complete division, early stage

Conjoined = incomplete division, later blastula stage

Question 22

Cleft lip/palate

Answer 22

Division errors in weeks 2-8
Genetic disposition 
Environmental factors =
Alcohol
Cigarette use
Organic solvents
Exposure to lead 
Illegal drugs 
Vitamin deficiency

Question 23

Defects during pregnancy

Answer 23

By teratogens (eg - X-rays, syphilis)
Congenital rubella syndrome (CRS) = malformations of fetus, time of maternal infection determines type and severity, malformation of heart, eyes or brain, liver, spleen, and bone marrow problems, growth retardation, deafness

Question 24

Smoking effects

Answer 24

Decreased fertility 
Placenta abruption 
Spontaneous abortion 
Low birth weight 
Increased perinatal death (20+weeks)
Increased neo-natal mortality 
Premature birth 
Congenital malformations
Behavioural problems (eg - ADHD)
Increased childhood cancers

Question 25

Fetal alcohol syndrome

Answer 25

Premature differentiation of mesenchyme (first 8 weeks)
Cell atopsis
Reduced head size and distinctive facial features
Neural effects
Variable degree of birth defects and mental retardation
DNA damage?
ADHD?

Question 26

Dietary

Answer 26

Folic acid 
Synthesizes, repairs, and methylates DNA
Needed for cell division 
RBC production 
Found in fruits and veggies

Question 27

Neural tube defects

Answer 27

Due to folic acid deficiency
Spina bifida = incomplete vertebrae formation, incomplete closure
Meningocoele = spinal cord lining protrudes

Question 28

Cerebral palsy

Answer 28

Decreased oxygen delivery during pregnancy and delivery
Muscle tightness or spasms
Difficulty with motor skills (walking or running, writing or doing up buttons)
Difficulty in perception and sensation