Subfertility and its Causes Flashcards
What is the definition of subfertility?
Failure to conceive after a year of regular unprotected intercourse
What is the pathology behind subfertility?
- Ovulatory problems
- Male sperm problems
- Tubal problems
- Cervical problems
- Sexual problems (psychological)
Describe the normal process of egg maturation?
- At the beginning of the cycle low oestrogen levels cause increased levels of GnRH and consequently FSH and LH
- These hormones stimulate the maturation of several ovarian follicles
- The oocyte follicles produce estradiol which has a neg feedback effect so that FSH and LH levels fall
- The effect of this is that only one dominant follicle will survive
- As this oocyte follicle matures, more and more estradiol is produced, exerting a positive feedback effect on FSH and LH (surge)
- The oocyte ruptures and the follicle becomes the corpus luteum
What factors can cause ovulatory problems?
- Group I: Hypothalamic hypogonadism/pituitary failure (anorexia, exercise, stress)
- Group 2: hypothalamic-pituitary-ovarian dysfunction (PCOS), hyperprolactinaemia (pituitary adenomas)
- Hyper/hypothyroidism
- Ovarian failure
What is the definition of PCOS?
USS appearance of multiple (>12) small follicles in an enlarged ovary
This is because, due to hyperandrogenism, all the eggs mature equally (but not enough), without one dominant follicle maturing. These accumulate on the edge, causing anovulation.
These woman display disordered LH production and peripheral insulin resistance (higher risk of GD)
How is PCOS diagnosed?
2/3 of:
- PCO on ultrasound
- Irregular periods (cycle >42 days)
- Raised testosterone (hirsutism, biochemical markers, acne)
What investigations should be done for a person with suspected PCOS?
Bloods: LH, FSH, TFTs, prolactin, testosterone, fasting lipids and glucose
Imaging: transvaginal USS
How should the menstrual irregularity of PCOS be managed?
Lifestyle modification, weight loss, combined oral pill, metformin
How should anovulatory sub fertility be managed conservatively?
Lifestyle changes and treatment of associated disease
How should sub fertility in association with PCOS be managed?
CLOMIFENE
- antioestrogen
- fools pituitary into believing there is no oestrogen, so it produces more FSH and LH
- monitor cycles by vaginal ultrasound for 6 months
METFORMIN
- also symptomatic treatment
LAPAROSCOPIC OVARIAN DIATHERMY/DRILLING
- punch through membranes so that the eggs can come out more easily
How should hypothalamic hypogonadism be treated?
- Daily SC injection of FSH and LH
2. GnRH pump
What factors can cause abnormal sperm release?
Drugs, genetic, varicocele, antiserum antibodies, infections
How is sub fertility investigated?
- Semen analysis
- Endocrine evaluation
- Tubal patency
- Pelvic USS screening
- Laparoscopy (and dye test)
- Hysteroscopy
What are the common causes of tubal problems?
- Infection (PID)
- Endometriosis
- Previous surgery/sterilisation
How does intrauterine insemination work?
Inject washed sperm directly into the cavity of the uterus
INDICATIONS: unable to have sex (physical, psychological), same sex couples
How does IVF work?
Embryos fertilised outside the uterus and transferred back (requires normal ovarian reserve)
Often the follicles are given GnRH analogue to help maturation
What are the risks associated with IVF?
- Miscarriage/ectopic
- Preterm delivery
- Multiple pregnancy
What is intracytoplasmic sperm injection?
Injection of one sperm right into the oocyte cytoplasm. This is usually used for male factor infertility