Parturition and Menopause (Lec 16)

Question 1

Normal Pregnancy Duration

Answer 1

Normal pregnancy lasts for ~40 weeks or 280 days after the last menstrual period

Question 2

Naegele’s Formula

Answer 2

Used to estimate date of birth: +7 days to last menstrual period, -3 from the month and +1 year

Question 3

Signs of Labour

Answer 3

• Blood stained or brownish discharge
• Coordinated muscular contractions
• Water breaks, amniotic sac breaks releasing fluid to pass out birth canal

Question 4

3 Stages of Labour

Answer 4

1. Dilation of cervix: longest stage, cervical opening enlarges 8-10 centimetres
2. Delivery of baby: begins when cervix is completely dilated, crowning (baby’s head visible)
3. Delivery of the placenta: expulsion of the afterbirth

Question 5

Types of Birth: Natural Birth

Answer 5

Delivery of baby without using drugs or surgery during birth

Question 6

Types of Birth: Induced Labour

Answer 6

Stimulation of uterine contractions before they occur spontaneously

Question 7

Types of Birth: Breech Birth

Answer 7

When baby delivered either feet first or buttocks first

Question 8

Types of Birth: Cesarean Section

Answer 8

Surgical incision made through mother’s abdomen and uterus to deliver baby

Question 9

Types of Birth: Episiotomy

Answer 9

Incision made between vagina and anus to help with crowning of the baby, to prevent muscles from tearing

Question 10

Types of Birth: Vacuum Extraction

Answer 10

Assists mother if she becomes tired, cup on baby’s head with slight suction

Question 11

Types of Birth: Forceps

Answer 11

To guide baby’s head out of birth canal

Question 12

Epidural

Answer 12

Pain relief (local anaesthetic) administered in the women’s lower back

Question 13

Apgar Scale

Answer 13

Assessment test of a newborn on a 1-10 scale

Question 14

Phases of Uterine Function

Answer 14

Phase 0: Quiescence (Progesterone)

Phase 1: Prepare for labour, cervical ripening, uterine contractility (Progesterone, estrogens, cytokines, prostaglandins)

Phase 2: Active labour (Oxytocin, prostaglandins)

Phase 3: Involution (Oxytocin)

Question 15

Regulation of Parturition

Answer 15

Increased levels of Corticotropin-releasing hormone (CRH) -> stimulates fetal pituitary to release ACTH -> stimulates mature fetal adrenal glands to release:

1. Cortisol: fetal lung development, production of surfactant
2. DHEA (Dehydroepiandro-sterone sulfate): converted to estrogen, uterine contractions

Question 16

Important Hormones: Progesterone

Answer 16

• Maintains pregnancy
• Relaxation of uterine muscle
• Down-regulates oxytocin receptors
• Suppresses spontaneous contractions

Question 17

Important Hormones: Estrogens

Answer 17

• Involved in labour
• Stimulate myometrial contractions
• Up-regulates oxytocin receptors
• Preps uterus for coordinated contractions

Question 18

Important Hormones: Prostaglandins

Answer 18

Stimulates more vigorous myometrial contractions

Question 19

Important Hormones: Oxytocin

Answer 19

Strongest stimulator of uterine contractions

Question 20

Parturition: Initiation of Labor

Answer 20

• Estrogen from ovaries induces oxytocin receptors on uterus
• Oxytocin from fetus and mother’s pituitary stimulates uterine contractions and placental production of Prostaglandins
• Prostaglandins stimulate more vigorous contractions of the uterus

Question 21

Miscarriage

Answer 21

Loss of fetus (spontaneous abortion) before the 20th week

Question 22

Stillbirth

Answer 22

Death of a baby during pregnancy after 20 weeks of gestation but before delivery. Occurs in ~1:200 pregnancies

Question 23

Menopause

Answer 23

Occurs in women at average age 50-55 years and menses have ceased for an entire year. Declining estrogen levels cause:
- atrophy of reproductive organs and breasts

Question 24

Male Climacteric

Answer 24

Circulating levels of Testosterone decrease with age causing:

• erectile dysfunction
• decreased libido
• declining sperm production/motility