Fertility Perservation Flashcards
Why do we need to preserve fertility?
- Cancer, radiotherapy and chemotherapy can cause premature gonadal failure.
- 20% of patients with premature ovarian failure have autoimmune associated disease such as diabetes, thyroid dysfunction, addition syndrome, Cohen’s disease
- Surgery endometriosis, infection, family history of premature ovarian failure and idiopathic causes.
How does cancer link to fertility?
Half the people diagnosed with cancer now survive and almost 75% of children are now cured.
Cancer therapy can result in infertility or premature gonadal failure leading to a significant quality of life issues for young survivors
What are some surgeries that can preserve fertility in females?
- Hysterectomy or oophorectomy may be performed
- Ovarian or cervical cancers may undergo trachelectomy, which removes the cervix but leaves the uterus in situ
What are limitations to the surgery?
- surgery can cause scarring in the uterine tubes which may obstruct them
What are surgeries to perserve fertility in males?
- unilateral orchidectomy reduces sperm conc, reduced spermatogenesis is reversible within the first year after surgery.
- Retroperitoneal lymph node dissection can cause serious disruption of ejaculation(testicular or renal cell carcinoma)
- Radical prostectomy may lead to erectile dysfunction, retrograde ejaculation and poor semen quality
- Rectal cancer surgery may lead to erectile dysfunction
Radiotherapy causes damage to males reproductive system:
Irradiation in the G2 phase of the cycle induces chromatid defect.
Analyse dose/response of peripheral blood cells, enabling restriction of dose.
As you increase dose of radiation the damage becomes more reversable :
0.5 Gy = Transient suppression with subsequent recovery of spermatogenesis.
2–3 Gy = Period of azoospermia after which full recovery is expected within three years.
4–6 Gy = Recovery is not universal and may take up to five years.
6 Gy = High risk of permanent sterility.
Total body irradiation (TBI) with high-dose chemotherapy will sterilise men.
Radiotherapy causes reproductive damage to females
Ovarian damage depends on patients age, dose & field
of irradiation. Radiation to the pelvis can have a direct
negative impact on ovarian function and the uterus by
altering vascularisation.
The damage is dose dependent:
Doses of 4-6 Gy can produce a loss of 50% of the follicle
population.
Total body irradiation (typically 10-12 Gy) causes
infertility, recovery of ovarian function occurs in 10-
15% of cases.
Non-pelvic radiation, especially head and neck may
disrupt the hypothalamic-pituitary axis.
chemotherapy on males
Most chemotherapeutic agents are gonadotoxic.
Alkylating agents pose the greatest risk to
spermatogenesis.
DNA of spermatozoa can also be damaged by low doses of chemotherapeutic agents – DNA integrity may be recovered after treatment.
!Not all chemotherapy regimens affect male fertility,
preservation is only offered where a high risk of
azoospermia or DNA damage is expected.
chemotherapy on females
Several mechanisms including follicular depletion,
vascular damage, cortical fibrosis.
Alkylating agents such as cyclophosphamide are most
gonadotoxic since they are not cell cycle specific and
also affect other cells in the ovary.
All patients exposed to chemotherapy might have a diminished ovarian reserve.
Younger patients 20% - 90% affected .
Probability of early menopause is at least 25% at age
30 years. Infertility at 35 years >40%.
Women over 40 years have a 90% chance of
amenorrhoea subsequent to multi-agent
chemotherapy.
The effect of chemotherapy on the ovary
- no. of surviving primordial follicles following exposure correlates inversely to dose of chemotherapy
- if a women is younger and has more primordial follicle you need to try preserve it from damage so use lower doses.
- likely to get early menopause : the age of a women and dose-dependent
Patient psychological concerns & reactions
- Digesting the ‘double blow’. Bewildered and overwhelmed.
- Feelings of being ‘out of control’ and struggling to regain a sense of personal stability.
- Sense of being robbed of one’s manhood or womanhood
- Grief over the possible loss of opportunity to fulfil one’s dreams
- Anger toward the medical community for failing to provide adequate information regarding fertility risks.
Fertility preservation options
What is cryopreservation?
egg freezing
a process in which women’s oocytes are extracted and frozen.
Oocyte cryopreservation
-Controlled ovarian stimulation using gonadotrophins for 8-12 days given to women before oocyte retrieval.
-The entire process takes minimum of 2-3 weeks depending upon patients menstrual cycle
-Exposure to high levels of estradiol is contraindicated.
There are controversy on this issue - arguments that a short term increse is not harmful.
-ovarian stimulation protocaols including aromatase inhibitors have been described in order to avoid excessive high estradiol levels
What are advantages of cryopreservation?
-Suitable strategy for patients who can
postpone oncologic treatment and where
controlled ovarian stimulation is not contraindicated.
-Valid option for post pubertal women
without a male partner or those who do not
want donor sperm or object to embryo
cryopreservation.
