Session 5 Conception, subfertility and contraception

• male sexual response:

  • Excitement:
  • Development of penile erection
  • Under parasympathetic control (S2-S4)
  • NO release
  • Smooth muscle of helicine arteries relaxes
  • Helicine arteries vasodilate and fill sinusoids with blood
  • Increased pressure in penis decreases venous return
• male sexual response:

  • Plateau:
  • Contraction of ischiocavernosus
  • venous engorgement and decreased arterial inflow to increase penile erection
  • Engorging and elevation of testes
  • Secretion from accessory glands
• male sexual response:

  Orgasmic: Emission

  • Ejaculate squeezed into penile bulb
  • Under sympathetic control (L1 and L2)
  • Peristalsis of vas deferens and seminal vesicles
  • Prostatic smooth muscle contracts
• male sexual response:

  • Orgasmic - Ejaculation
  • Semen is expelled from the urethra
  • Under somatic control via pudendal nerve (S2–S4)
  • Contraction of glands and ducts
  • Internal urethral sphincter contracts
  • Ischiocavernosus contracts to stabilise the penis
  • Bulbospongiosus contracts to propel ejaculate
• male sexual response:

  • Resolution:
  • Contraction of vascular smooth muscle in corpora cavernosa
  • Increased venous return
  • Penis returns to flaccid state
• female sexual response:

  • Excitement phase:
  • Lengthening and expansion of vagina
  • Vaginal lubrication
  • Elevation of uterus
  • Erectile tissue engorgement
• female sexual response:

  • Plateau phase:
  • Further vaginal lubrication and uterine elevation
  • Clitoris withdraws under hood
  • Labia minora deepen in colour
• female sexual response:

  • Orgasmic phase:
  • Rhythmical contraction of lower 1/3 of vagina
  • Contraction of uterus and anal sphincter
• female sexual response:

  • Resolution phase:
  • Erectile tissue returns to unaroused state
  • Uterus descends
  • Vagina shortens and narrows
• Acrosome releases two enzymes?

  • Hyaluronidase: breaks down bonds between granulosa cells (corona radiata)
  • Acrosin: breaks down zona pellucida proteins.
• Fusion of ovum and sperm membranes triggers Ca2+ release from smooth endoplasmic reticulum.
• Zygote: fertilised ovum

  Embryo: 2-8 wks following fertilisation

  Fetus: 9 weeks to term
• Complete molar pregnancy:

  • 46 paternal chromosomes (polyspermy)
  • No maternal chromosomes (empty ovum)
• Partial molar pregnancy

  • 46 paternal chromosomes (Polyspermy)
  • 23 maternal chromosomes
• In the excitement phase of the male sexual response, endothelial cells are stimulated to release nitric oxide.
• The biochemical removal of sperm surface glycoproteins which initiates the whiplash movement of the sperm tail is known as capacitation.
• Delay in conception after 1yr of regular unprotected sexual intercourse or six cycles of intrauterine insemination - subfertility
• Primary subfertility: delay in conception for a couple who have no previous pregnancies.
• Secondary subfertility: delay in conception for a couple who have conceived previously, even if pregnancy did not end with a successful outcome.
• Identify levels of hormones in ovulatory disorders

  A) low

  B) low

  C) low

  D) High

  E) High

  F) low

  
• Group II ovulatory disorders?

  • PCOS
  • hyperprolactinaemia
• Diagnosis of PCOS requires 2 of the following Rotterdam criteria:

  • Oligo- and/or anovulation
  • Clinical and/or biochemical hyperandrogenism
  • Polycystic ovaries
• Hyperprolactinaemia?

  • High prolactin reduces GnRH and therefore LH and FSH
  • Test if:- Symptoms of an ovulatory disorder, Galactorrhoea, Pituitary tumour
  • Treat with dopamine agonists.
• azoospermia: No spermatozoa in the ejaculate
• Identify the levels of hormones in males

  A) low

  B) low

  C) low

  D) high

  E) high

  F) low

  
• Identify treatment options for each!

  A) IVF

  B) IVF +/- ICSI

  C) Laproscopic

  
• Deliberate use of artificial methods or other techniques to prevent pregnancy as a consequence of sexual intercourse - contraception
• Barrier methods Advantages?

  • non-hormonal
  • reduced risk of STIs with some
  • only need to be used when sex occurs
  • cap and condoms can be used without seeing a healthcare professional.
• Barrier methods Disadvantages?

  • not as effective as other options
  • require cooperation with sexual partner
  • may interrupt spontaneity of sex
  • require physical dexterity
  • diaphragms and caps require spermicide.
• Progestrone only pill - desogestrel
• Internal and external condoms help prevent sexually transmitted infections.
• IUS can be used as part of hormone replacement therapy, or to manage heavy menstrual bleeding and some types of endometrial hyperplasia
• The CHC may help polycystic ovarian syndrome, acne, pre-menstrual syndrome and endometriosis
• The implant and injection may help endometriosis
• Up to 72 hours after UPSI - Emergency Contraception - Levonorgestrel (tablet)
• Up to 120 hours after UPSI - Emergency Contraception - Ulipristal acetate(tablet), Copper IUD
• Cu-IUD - Non-hormonal

  • Possible reduced risk of endometrial and cervical cancer.
• IUS - may protect against ovarian cancer.
• Long acting reversible contraception? (LARCs)

  • Progestogen-only injectable
  • Copper intrauterine device
  • Progestogen-only intrauterine system
  • Progestogen-only subdermal implant