Reproduction Lectures 2021 - Contraception & Infertility Flashcards
How is contraception increased throughout the world?
Population control
Lifestyle choices
In the US ~ half of all women will have an unplanned pregnancy between
15 and 44
Approximately 50% of unintended pregnancies in the US occur…
even when contraceptives are used
Tubual ligation in females is typically…
reversible
Vasectomy in males is…
not so easy to reserve but can
- normally have storage of sperm in case
Combination Pill
~ 30 different brands available in North America all contain synthetic estrogen and progesterone
Typically 2 estrogen types: mestranol or ethinyl estradiol
and one of 8 progesterones: ethynodiol diacetate, norethidrone, norethindrone acetate, norethynodrel, norgestrel, desogestral, gestodene or norgestimate
The combination pill blocks ovulation, conception and implantation
Mild and serious side effects as well as benefits independent of their intended use. Delay in fertility when women come off the pill
Ppl on the combo pill have…
elevated levels of constant concen. of E & P
- these will (-) feedback & limit appro. prod. of a viable egg
Even if fertilization does occur when on pill, the…
imbalance can prevent appro. dev. of endometrial lining & implantation but with inappro. use it can fail
Why do some females use P only pills that are not as effective as P & E ones?
nursing moms normally - they don’t want to get pregnant at that time, so P only pill is used b/c of the complications that elevated levels of E’s might have in terms of supporting & breastfeeding a child
What are the mild & severe side effects of the combo pill as well as the benefits?
mild - nausea, weight gain, fluid retention
serious - possible increase for breast or cervical cancer
benefits - decrease in risk of ovarian cancer
Hormone delivery
- Progesterone implants (intradermal) - slow release method
- Injectable hormones
- Contraceptive patch - slow release method
- Vaginal ring - can deliver concen’s. of hormones within lower part of FRT, making a v. unfav. envir. for sperm to survive
“Morning after pill”
- Again progesterone and estrogen based
- Success rates are highly variable
- Usually requires more than a single pill (1- 5)
Physical contraception
• IUD’s–T-shaped flexible plastic sometimes impregnated with progestogens
– Reduces sperm motility and viability, influences development and maturation of the ovum, blocks implantation
• Diaphragm, sponge and cervical caps (physical barrier to the movement of sperm through FRT)– Used in combination with spermicide (stops sperm ability to swim)
– Easily reversible
Male contraception
• Condom
– Limits STI’s and STD’s eg: HIV
• Coitus interuptus
• The male “pill”
– Why is this not a reality?
– Testosterone derivatives have undergone clinical trials but success rates are low in regard to creating infertility (>40% in caucasian males)
– Androgens alone have significant side effects
– Why not an androgen in combination with an estrogen?
– Specific calcium channels in sperm tails
Why not an androgen in combination with an estrogen?
male psyche
- males have potential to repro. until they die - taking what is perceived to be a female sex steroid to limit their repro. potential
- hard to market
Surgical contraception/sterilisation
Much more common in females than males
• Tubal ligation - tying FT’s (reversible)
• Hysterectomy - removal of ovaries (NOT reversible)
• Vasectomy - destruction of vas deferens
• Orchidectomy - removal of testes (NOT reversible)
When is an orchidectomy normally conducted?
if there’s underline issues with male (prostate cancer for ex)
Infertility
• Considered infertile if after a year there is no pregnancy Can be from male (35%), female (35%) or both (20%) (& 10% unknown)
Infertility in males:
reduced sperm count (<20million.ml-1) or abnormally high defective sperm. Autoimmune disorders
Infertility in females:
production of antibodies against sperm or failure to implant developing zygote, blockage, ciliary dysfunction or endocrine basis
Endometriosis
endometrial lining blocks FT as it joins the uterus & now sperm has no way to get to it & fertilize that egg
Oligospermia
• Low sperm count, oligospermia, is the leading cause;
Possible reasons:
– Endocrine dysfunction
– Varicocele (varicous veins in the scrotal sac - has increase temp.)
– Retrograde ejaculation (things go backwards)
– Orchitis - infected testicles
– Cryptorchidism - testis fail to descend
– Impotence - erectile dysfunction
In vitro fertilisation
• First “test-tube baby” born in Bristol, England in 1978
Ovarian stimulation and egg retrieval: Fertility drugs (gonadotropins) are administered to the woman to stimulate the maturation of several large follicles followed by hCG. Prior to ovulation 10-12 eggs are removed from the ovary (typically 3 are implanted)
Fertilisation and embryo transfer:
Sperm obtained from the male and placed in a fluid that nourishes and CAPACITATES the sperm
The fertilised egg is cultured to ensure normal embryonic development and then inserted into the woman’s uterus.
Robert Edwards (1st to do this) - Nobel Prize in Med in 2010
In Vitro Fertilization (IVF)
external fertilization in petri disk and transfered as pre-embryos
Gamete Intrafallopian Transfer (GIFT)
ova surgically implanted into FT
- Artificial Insemination Husband (AIH) b/c of timing you have to do it artificially instead of naturally
Zygote Intrafallopian Transfer (ZIFT)
external fertilization and transfered as zygotes (implanted at an earlier stage than IVF)
Egg Donation
external fertilization and transfered into uterus as pre-embryos
- female is incapable of producing viable eggs, so there is a donor (complication happen)
Gestational Carrier
external fertilization by a diff. woman that will carry it in her uterus and transfered as pre-embryos into uterus
Surrogate Pregnancy
ovum transfered to fallopian tube
- AIH or natural
- male has intercourse with a diff. woman who will give birth to that child & then couple takes that child
Suleman Octuplets
Nadya Suleman is mother
- made it to 31 weeks gestation –> C-section
2 sets of mono
2 sets of dizy (sometimes 1 might not make it to full term)
Normally, for IVF the gynocologist implants 3 blastocysts into mom, in hopes of 1 making it to term
- she requested 6 blastocyts be implanted, doctor implanted 12!
