Obgyn 1 - Physiology Of The Reproductive Cycle

Front 1

Menses start around age

Back 1

13

Front 2

Menses end around age

Back 2

52

Front 3

Cycle lengths are most variable

Back 3

At start and end of cycling
Most stable cycle length from 15-45

Front 4

Normal range of cycle lengths

Back 4

21-35 days, usually 26-30

Front 5

Menstrual flow duration and blood loss

Back 5

Average of 5 days (3-7)
20-160mL blood loss, average of 60

Front 6

Hypothalamus secretes

Back 6

GnRH

Front 7

Pituitary secretes

Back 7

FSH and LH

Front 8

Ovary secretes

Back 8

Estrogen and progesterone

Front 9

GnRH kinetics

Back 9

Requires pulsatile stimulation to induce release of FSH and LH
2-4 minute half-life

Front 10

FSH and LH structure

Back 10

Glycoproteins - common alpha subunit, different beta subunits

Front 11

Estradiol synthesis

Back 11

Formed by aromatization of androgens
Derived from cholesterol

Front 12

Estradiol action

Back 12

Increased number of granulosa cells and FSH receptors on granulosa cells
Crucial in dominant follicle selection
Negative feedback on GnRH

Front 13

Estradiol levels

Back 13

Low around menses
Highest in pre-ovulatory follicles
Normally low in pre-pubertal girls and menopausal women

Front 14

Two-cell theory

Back 14

LH acts on theca cell to cause cholesterol to androgen conversion
FSH acts on granulosa cell to aromatize androgens to estrogens

Front 15

Progesterone action

Back 15

Prepares endometrium for implantation
Negative feedback on GnRH

Front 16

Progesterone synthesis

Back 16

Synthesized by corpus luteum

Front 17

Menstruation

Back 17

Secretory endometrium synthesizes prostaglandins under influence of progesterone
Endometrium sloughs, with cramps, contractions, and ischemic pain due to liberated prostaglandins

Front 18

Follicular phase

Back 18

Endometrium proliferates under direction of FSH
Variable in length

Front 19

Folliculogenesis

Back 19

Hundreds of follicles develop each cycle
Modest FSH rise in late luteal phase starts the process towards pre-antral follicle formation
Estradiol mediates atresia of non-dminant follicles
Dominant follicle makes gonadotropins

Front 20

Ovulation

Back 20

Estrogen peaks 24-36 hours before ovulation
Peak stimulates LH surge, causing further androgen production and atresia of non-dominant follicles
Rupture of follicle and ovulation

Front 21

Luteal phase

Back 21

Corpus luteum produces estradiol and progesterone
Fixed life span of about 13-14 days
Progesterone negatively feeds back on pituitary, causing low levels of FSH

Front 22

Types of assisted reproduction

Back 22

IVF
Intrauterine insemination
Oocyte donation
Gestational carrier

Front 23

Steps to IVF cycle

Back 23

Screening and test preparation
Controlled ovarian hyperstimulation
Egg retrieval
Embryo transfer
Follow-up management

Front 24

Controlled ovarian stimulation in IVF

Back 24

Causes cohort of oocytes to develop and overrides dominant follicle selection
Inhibition of ovulatory surge with GnRH analog

Front 25

Egg retrieval in IVF

Back 25

Performed via transvaginal ultrasound guidance
Eggs inseminated the same day
Progesterone supplementation begins

Front 26

Embryo transfer in IVF

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Assessment of embryo on day 3
Implantation on day 5
Blastocyst transfers are most successful and can help reduce multiple gestations

Front 27

Cryopreservation

Back 27

Usually at blastocyst stage
Not as successful as fresh cycles

Front 28

Preimplantation genetic diagnosis

Back 28

Tests for known disease states
Screen around day 3

Front 29

Oocyte donation indications

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Women without eggs or poor quality eggs
Women with genetic issues
Success tied to age of donor

Front 30

Gestational carrier indications

Back 30

Women unable to carry pregnancy due to medical issues or lack of functioning uterus