Physiology Of Menstruastion

Question 1

What is the cause of the menstrual cycle?

Answer 1

• normal HPO axis
• patent genital tract

Shedding of the endometrial lining following failure of fertilization of the oocyte or failure of implantation
- controlled by hypothalamus -> pituitary -> ovarian
-> access through hormonal communication

• flow: 4 +-2 days
• length: 28 +-7 days
• amount: 20 - 60ml

Question 2

What is the role of the hypothalamus in the menstrual cycle?

Answer 2

1- release of gonadotropin release hormones in a pulsation manner
2- stimulates the gonadotrophs of the anterior pituitary to release LH & FSH

GnRH: decapeptide: half life <10 min

Question 3

What are the phases of the endometrial/ovarian cycle?

Answer 3

1- menstrual/follicular phase
- shedding of endometrium due to loss of progesterone from corpus luteum degeneration
- GnRH/FSH/LH restart cycle

2- proliferative/ovulation phase
- estrogen increases in late follicular phase to build endometrium & induce ovulation
- LH surge induces ovulation on day 14

3- secretory/luteal phase
- high progesterone maintains corpus luteum for 14 days
- basal body temperature increases
- high estrogen & progesterone negatively feedback on hypothalamus and pituitary

Question 4

What is the presentation of a Mullerian obstruction?

Answer 4

• increasing abdominal pain (cyclic) in early adolescence
• pelvic mass: Hematocolpus
• bulging membrane at vaginal entrance

Question 5

How is an imperforate hymen treated?

Answer 5

• hymenectomy
• hymenotomy

Question 6

What is the cause of MRKH syndrome and how is it diagnosed?

Answer 6

Mullerian agenesis -> failure of formation of uterus & upper vagina
- ovaries are present and functioning

Presents as primary amenorrhea with normal secondary sexual characters

Question 7

How is Mullerian agenesis diagnosed?

Answer 7

Screening -> US
Diagnosis -> MRI

Question 8

How is MRKH syndrome treated?

Answer 8

• psychological support
• creation of vagina comfortable for intercourse
• if patient wants children -> ova retrieval and surrogacy

Question 9

How is cervical age sis diagnosed & treated?

Answer 9

• clinically -> amenorrhea & cyclic pain
• treat by -> laparoscopic uterovaginal anastomoses

Question 10

What is the cause of uterus didephylis & how is it diagnosed?

Answer 10

Failure of fusion of Müllerian ducts
- US & MRI to confirm

Presentation
- miscarriages & preterm deliveries or infertility
- 2 separate vaginas & cervices

Question 11

What is the cause of bicornuate uterus & how is it diagnosed?

Answer 11

Partial non fusion of the Müllerian ducts at the level of the fundus
- fundal indentation of 1cm or more
- if septum is dividing vagina & cervix -> bicollis
- diagnosed by US, MRI, or HSG
- presents with preterm delivery or malpresentation

Question 12

How is bicornuate uterus & didelphys treated?

Answer 12

Strassman metroplasty for patients with recurrent miscarriages

Question 13

What is a unicornuate uterus?

Answer 13

• only half of the uterus is formed
• other half is not formed of rudimentary with ipsilateral renal agenesis

Question 14

How is a unicornuate uterus diagnosed?

Answer 14

• diagnosed with MRI -> banana shaped uterus
• US -> HSG
• high rate of spontaneous abortions

Question 15

What are the types of separate uterus?

Answer 15

• partial -> doesn’t involve cervix
• complete -> reaches the cervix
• separate uterus & vagina -> extends till vagina

Question 16

How is a separate uterus diagnosed & treated?

Answer 16

• presents with miscarriages & premature delivery
• treated by hysteroscopic removal of septum

Question 17

What are the types of vaginal septums?

Answer 17

Longitudinal
- can have normal menstrual cycle
- asymptomatic if not obstructive
- treat by surgical excision

Transverse
- presents with primary amenorrhea & cyclic pelvic pain
- can be associated with uterus didelphys
- MRI should be done before surgical correction to make sure there’s no cervical absence