Fertility Management

DO SOME EXTRA READING IN THE TEXTBOOK :D

Surgical Contraception | Vasectomy

Action → block sperm transport through the male reproductive tract

Advantages → no sex interruption, continuous protection

Disadvantages

• wait 3 months to be completely sterile because natural degeneration or purging (by 20 ejaculations) of residual sperm stored in the ductus deferens ampulla

• expensive

• irreversible

• no STI protection

Surgical Contraception | Tubal

Action → block egg transport through the uterine tube

advantages 

• no sex interruption

• continuous protection

• decreased risk of ovarian cancer

Disadvantage 

• expensive

• irreversible

• no STI protection

Hormonal Contraceptive | POC | Progesterone-Only Contraceptive

Action → thickens cervical mucus, disrupts oviduct transport and creates hostile endometrium

Ectopic pregnant → thicken mucus, oocyte suck and implants in the wrong area. 

advantages → if COC (estrogen) is contraindicated

Disadvantage

• prescription

• daily use

• no STI protection

• decreased levels of protection than COC

Contradiction → Stroke (progesterone increased water retention → increases hypertension → increases stroke).

Hormonal Contraceptives | COC | Combined Oral Contraceptive 

action 

• suppresses follicle stimulation, ovulation, and CL formation

• thickens cervical mucus

• disrupts oviduct transport and creates hostile endometrium

Advantage 

• works at 3 levels

• decreased risk of ovarian cancer

• regular and lighter menses

Disadvantage

• prescription

• daily use

• no STI protection

• nausea, breast tenderness, and headaches

contraindications

• >35 years + smoking, diabetes, HTN, obesity, migraine

• CV complications

• breast cancer

• postpartum breastfeeding (block action of PRL ∴ prevents milk synthesis)

Failure Rate

failure rate = how often method fails if used exactly as directed

1% failure = 1 woman would fall pregnant if 100 women used the method for 1 year

typical failure rate much higher than perfect use

Barrier/Chemical Contraceptives | Condoms

• action

  prevents sperm deposition in the vagina

• advantages

  • STI protection

  • nonprescription

• disadvantages

  • interrupts sex

  • single-use

Barrier/Chemical Contraceptives | Diaphragm

• action?

prevents movement of sperm in the female reproductive tract

• disadvantages?

  • prescription

  • requires fitting

  • timing

Barrier/Chemical Contraceptives | Spermicide

• action

prevents movement of sperm through the female reproductive tract

• advantage

  • some STI protection

  • nonprescription

• disadvantages

  • unpleasant for some

  • time-sensitive

Barrier/Chemical Contraceptives | IUD

• action

  prevents implantation of blastocyst

• advantages

  • effective for years

  • no sex interruption

• disadvantages?

  prescription

Natural Contraceptives

• withdrawal

• rhythm method

• breast feeding

Relatives Failure Rate of The Contraceptives

1. surgical = lowest

2. hormonal = relatively effective

3. barrier/ chemical = high typical failure

4. natural methods = least reliable

for male contraception, which hormones could be targeted? what must be considered?

Hormones Targeted

Inhibin → suppresses FSH (unsupported Sertoli cells, no ABP)

ABP → prevent sequestration of testosterone to Sertoli cells

FSH

Consideration → must avoid disrupting endogenous testosterone levels

why is male contraception less common then female alternatives?

This is because you must suppress millions of sperm per day vs 1 egg per month

what processes do different contraceptive methods target?

Contraindication | This is more of an FYI not really important 

A contraindication is a specific situation, condition, or factor in which a particular treatment, drug, or medical procedure should not be used because it could be harmful to the patient.

Types of Contraindications

1. Absolute contraindication

   • The treatment must never be given because the risk outweighs any possible benefit.

   • Example: Giving isotretinoin (for acne) to a pregnant woman—it can cause severe birth defects.

2. Relative contraindication

   • The treatment might still be used, but with caution and only if the benefits outweigh the risks.

   • Example: Using a beta-blocker in someone with asthma—can worsen breathing, but may be necessary in some heart conditions.

Clinical Infertility

inability to conceive after 12 months of frequent unprotected intercourse

Clinical Sterility

cannot conceive

Fecundability

probability of achieving a pregnancy in 1 menstrual cycle

Fecundity 

probability of achieving a pregnancy resulting in live birth in 1 menstrual cycle

what proportion of infertility is male vs female?

roughly equal  → 35% female, 35% male, 20% both & 10% unknown

what are the male causes of infertility?

• poor sperm number/ motility/ morphology, due to?

  • hormone imbalance

  • hypogonadism

• testes and accessory gland dysfunction, due to?

  • cryptorchidism

  • varicocele

  • drugs/ toxins

• blocked ejaculatory ducts

• retrograde/ neurological ejaculation disorders

• anti-sperm antibodies (from trauma)

what are the female causes of infertility?

• ovulation and ovarian failure, due to:

  • hormone imbalance

  • PCOS

  • hypoplasia

• implantation failure, due to: 

  • abnormal endometrium

  • fibroids/ polyps

  • hormone imbalance

• failed sperm transport, due to: 

  • vaginal acid

  • abnormal cervical shape or mucus

• blocked oviducts

• anti-sperm antibodies

why does the chance of miscarriage increase with age?

• poorer quality of aged/ abnormal oocytes

• meiosis I begins at birth but cells arrested in prophase I, continues at puberty via pulsatile GnRH? Prolonged arrest can last up to 50 years. 

Cohesions (proteins that hold sister chromatids)  weaken with age which  causes problems like: 

1. incorrect microtubule to centromere attachment

   • chromosome segregation errors (nondisjunction) during metaphase I

   • increased aneuploidy rates with increased maternal age (eg. Down syndrome)

how do we identify the cause| Primary Analysis

hormone assays → detect cycling, ovulation, and spermatogenesis

ultrasound → presence of follicles or cysts, endometrial thickness

test tubal patency → blockages/ occlusions

semen analysis → number/ morphology

blood tests → anti-sperm antibodies

how do we identify the cause| Secondary Analysis 

aparoscopy/ endoscopy → uterine/ oviduct blockage

endometrial/ testicular biopsy

Aspermia

no ejaculate (accessory glands affected)

Azoospermia?

no sperm in ejaculate

Oligozoospermia

<15 million/ mL

Normospermia

>15 million/ mL

how do you calculate sperm count?

[sperm] \times count \times square multiplication factor \times dilution factor

ART | Artificial insemination (AI)

• most motile/ functional sperm are isolated via a Percoll gradient

• intrauterine insemination (IUAI) by catheter

• synchronised with natural or induced (FSH + LH) ovulation

ART | In vitro fertilisation (IVF)?

• oocyte is retrieved from the ovary and sperm is artificially capacitated

• natural penetration, fusion, and fertilisation in vitro

• embryo cultured in vitro then blastocyst is transferred to the uterus for implantation

ART | Intracytoplasmic sperm injection (ICSI)

• fertilisation incompetent sperm are directly injected into the oocyte

• injected oocyte is chemically activated with $\small\ce{Ca^2+}$ to develop

ART | zygote intrafallopian transfer (ZIFT)

like IVF except fertilised zygote is transferred to the oviduct

ART | gamete intrafallopian transfer (GIFT) 

oocyte is transferred to the oviduct to bypass the blockage, then IUAI → the oocyte has been moved to a position where it can be fertilised, sperm must be introduced to optimise the success rate

ART | Cryopreservation 

cryopreservation of sperm, oocytes or embryos

what male infertility factors influence ART selection?

• with decreased sperm quality:

  1. AI for suboptimal motility or count

  2. IVF for very poor motility or count

  3. ICSI for immotility or fertilisation incompetence

what female infertility factors influence ART selection?

• with increased embryo development:

  1. GIFT for tubal blockage

  2. ZIFT for tubal blockage and/ or very poor sperm motility or count

  3. IVF for tubal blockage and/ or very poor sperm motility or count

Ideal Contraceptive 

• The “ideal contraceptive”
  - 100% effective
  - 100% sexually convenient
  - 100% reversible
  - 100% free of dangerous side-effects
  - 100% free of nuisance side-effects
  - 100% maintenance-free
  - bonus – some good side-effects
  

• the ideal contraceptive does not exist