The biology of controlling fertility U2

In males Relatively constant level of FSH and ICSH in the bloodstream (pituitary hormones) Therefore, a steady quantity of testosterone is secreted and a steady quantity of sperm is produced

In females Interplay of pituitary and ovarian hormones result in the period of fertility being close to 3-4 days after ovulation The fertile period can be calculated through temperature and mucus Around 1 day after ovulation, a woman’s body temp rises by 0.5°C, it remains elevated during the luteal phase by the action of progesterone Mucus will be thin and watery to allow sperm easy access to the female reproductive system, after ovulation mucus will increase in viscosity due to progesterone levels

Can arise due to factors such as age, genetics, disease or health and lifestyle reasons including anorexia, obesity, drug misuse, smoking, stress and poor diet

Stimulating ovulation Artificial insemination In vitro fertilisation (IVF) Intracytoolasmic sperm injection (ICSI)

Drugs that mimic the action of FSH and LH Drugs that prevent negative feedback effect of oestrogen on FSH secretion These drugs can cause super ovulation, which can result in multiple births These drugs are used when a woman fails to ovulate or to collect ova for IVF

Used when a man has a low sperm count Semen is collected and inserted into the female reproductive tract without intercourse taking place When enough semen with enough viable sperm is collected, all samples are defrosted and released into the uterus If a male parter is sterile, a sperm donor may be used

Used when a woman has blocked oviducts Eggs and sperm are removed and are left to fertilise in a culture dish, the zygotes are then incubated until they have formed embryos of at least 8 cells PGD is used to identify single gene disorders and chromosome abnormalities, the most suitable embryos are selected and used for implantation, unused can be stored for later use

Used when male has defective sperm or they are in very low numbers Drawing a healthy active sperm into a syringe needle and then injecting it directly into an egg to bring about fertilisation Commonly used as part of IVF treatment

Condom Diaphragm/cervical cap Calendar based methods IUD Vasectomy Tubal ligation

Barrier methods Physically block the ability of sperm reaching an ovum

Avoiding intercourse during fertile periods

Alters cervical mucus and prevents implantation of fertilised egg

Sterilisation, cutting and tying 2 (sperm ducts/oviducts), to prevent (the release of sperm during intercourse/sperm and egg meeting)

Combination contraceptive pill Mini pill Morning after pill

Combination of synthetic oestrogen and progesterone hormones that mimic negative feedback, preventing the release of FSH & LH from the pituitary gland, preventing the development and maturation of a follicle

Contains progesterone only Thickens cervical mucus, reducing sperm’s access to the uterus

High levels of synthetic oestrogen and progesterone Taken only after unprotected intercourse Delays ovulation or prevents implantation

Physical Chemical