Flashcards in Repro 7.2 Contraception and Infertility Deck (60)
What are the natural forms of contraception?
Why is coitus interruptus not 100% effective?
There is some sperm in pre-ejaculate
Why is the rhythm method not 100% effective?
Requires a regular cycle and no woman can be 100% certain when ovulation will occur.
In the rhythm method, what assumptions are made?
Sperm 7 days, ova 1 therefore with a regular 28 day cycle ovulation day will be day 14/15 and the fertile period is days 17-16 so sexual intercourse is avoided at these times
What are the barrier methods of contraception?
What are the benefits of condoms as a form of contraception?
Protect against STI
Effective if used correctly
How does a diaphragm work and what are the disadvantages?
Lies diagonally across the cervix
Needs correct fitting
Does not completely occlude sperm passage but holds sperm in acidic vagina and reduces survival time
How does the cap work as a method of contraception?
Fits across cervix
What is commonly used in conjunction with barrier methods of contraception?
What forms of contraception prevent ovulation?
Combined oral contraceptive pill
Depot progesterone (3 monthly injections)
Progesterone only pill (maybe)
Progesterone implant (maybe)
How can ovulation be prevented?
Inhibit follicular development and by negative feedback to the hypothalamus and pituitary
What forms of contraception inhibit sperm transport?
Progesterone mediated contraception:
How do progesterone contraceptives inhibit sperm transport?
Affect cervical mucous -> thick, hostile mucus
Can female sterilisation be reversed?
Yes - 50% success
How is female sterilisation achieved?
Occlude fallopian tubes by clips, rings or ligation
How common is recanalisation following a vasectomy?
rare - 1:300/500
What is a vasectomy?
Vas deferens are divided bilaterally. Ensure ejaculate is free of sperm before relying on it (usually takes approx 20 ejaculations)
What forms of contraception inhibit implantation?
Hormonal (COCP, POP, implant, depot)
How do hormonal contraceptives inhibit implantation?
Affect receptivity of the endometrium directly
Absence of corpus luteum further prevents preparation of the endometrium for implantation
What is in post-coital contraception and how does it work?
High dose of combined oestrogen/progesterone or progesterone only
May disrupt ovulation
In what time frame is post-coital contraception effective?
Up to 72 hrs after intercourse
(IUCD may also be used post-coital)
What is IUCD?
Inert or copper containing or progesterone impregnated (mirena coil)
Copper interferes with endometrial enzymes and may also interfere with sperm transport into fallopian tubes
Interferes with implantation
What are the risks of IUCD?
Infection (higher risk with copper)
Failure to conceive within 1 year
How many couples suffer from infertility?
What is the difference between primary and secondary infertility?
Primary - no previous pregnancies
Secondary - previous pregnancies, successful or not
What % of infertility is due to problems in the male, female and unexplained?
What are the potential causes of infertility?
Abnormal/absent sperm production
How common is anovulation and when is it most common?
Cause of 15-20% of fertility problems
Most common at extremes of reproductive life