infertility Flashcards
human fertility compared to other mammals
inefficient reproductive system
conception per cycle - 20% at peak age, declines with age
natural expectation of pregnancy
in a couple with no underlying fertility issues
80% of couples will become pregnant within the first year of trying
over 1/2 of the couples that didn’t get pregnant in the first year will get pregnant in the second year
90% of couples should achieve a pregnancy after 2yrs
why does female fertility decline
eggs production stops at birth
over the reproductive life span, the majority of the eggs perish with each cycle
fertility declines as egg numbers decline
eggs also don’t perform as well
begins after 35y/o
can we predict decline in fertility?
no
at the moment we can only plan ahead and use fertility tests (can’t determine if a women will get pregnant)
4 stages of conception
ovulation
sperm production
fertilisation
implantation
what does normal conception rely on
functioning hormonal axis and gonads ovarian reserve regular ovulation normal sperm production fertilisation: sperm and egg interaction, patent fallopian tubes normal uterine cavity for implantation
lifestyle factors affecting conception
age BMI smoking alcohol recreational drug use stress
clinical definition of infertility
inability to conceive over a 12mth period despite exposure to regular, unprotected intercourse
represents a prognosis based approach
provides practical guidance on when to initiate investigations
epidemiological definition of infertility
lack of conception after 2yrs in women of reproductive age (15-49) who are at a risk of becoming pregnant (sexually active, not using contraception)
demographic definition of infertility
inability to become pregnant with a live birth, within 5yrs of exposure
based upon a consistent union status, lack of contraceptive use, non-lactation and continuation of a desire for a pregnancy
global infertility trends
10% of woman affected globally, likely underestimated (based on demographic definition)
1/7 couples in western world, 1/4 couples in developing countries affected
difficulties with estimating prevalence of infertility
main challenge in getting true estimates is inconsistency in definition used to calculate prevalence
when to refer
no conception after 1yr of regular unprotected intercourse
referral earlier if:
- age >35
- known cause for infertility
types of infertility
1y - never managed to have pregnancy before/never fathered a child
2y - have had a pregnancy before/fathered a child but cannot manage again
causes of infertility
male - 30% female - 30% combined - 10% unexplained - 25% other - 5%
female infertility factors
ovulatory dysfunction 35% tubal factor 30% diminishing ovarian reserve 20% endometriosis - 10% uterine factor 5%
male infertility factors
hormone production
blockage of sperm transport
sperm production problems
erection and ejaculation problems
why may there be blockage of sperm transport
infection
prostate related problems
absence of vas deferens
vasectomy
why may there be issues with sperm production
genetic undescended testes infection torsion varicocele drugs radiation damage sperm antibodies heat
why may there be erection and ejaculation problems
prostate surgery damage to nerves ejaculation problems timing of intercourse medication
