2.3 - The Biology Of Controlling Fertility Flashcards
What is fertility?
Fertility is ability to conceive children.
What type of fertility do men show?
Main continuously produce sperm in their testis so show continues fertility.
What type of fertility do women show
Women show cyclical fertility, leading to a fertile period which lasts a few days during each menstrual cycle.
What changes happened to woman after ovulation?
A woman’s body temperature rises by around 0.5°C after ovulation and her cervical mucus becomes thin and watery.
What are infertility treatments and contraception based on?
Infertility treatments and contraception are based on the biology of fertility.
What percentage of couples become pregnant in the first year?
84% of couples will conceive naturally within 1 year of having regular, unprotected intercourse.
Percentage chance of pregnancy after 3 years
Couples who have been trying to conceive for more than 3 years without success have a 25% chance of becoming pregnant naturally within the next year.
Infertile meaning
Someone who is infertile has difficulty conceiving a child
Infertility treatments
Fertility drugs which stimulate ovulation
Artificial insemination
Intra-cytoplasmic sperm injection
In vitro fertilisation
What can be a cause of female infertility
Female infertility can be due to failure to ovulate
How can ovulation be stimulated?
Ovulation can be stimulated by drugs that prevent the negative feedback effect of oestrogen on FSH secretion.
How are other ovulation drugs used?
Other ovulatory drugs mimic the action of FSH and LH. These drugs can cause super ovulation.
What is super ovulation
Super ovulation is the production and release of multiple ova per menstrual cycle that can result in multiple births or be used to collect ova for IVF programmes.
When is artificial insemination useful?
Artificial insemination is useful when a male has low sperm count.
Artificial insemination process
Several samples of semen are collected over a period of time.
Sperm are placed inside the uterus near an oviduct using a catheter.
What happens is the male partner is sterile?
If the male partner is sterile (not producing gametes), sperm from a donor can be used. This is called donor insemination.
When is intracytoplasmic sperm injection used?
If mature sperm are defective or very low in numbers ICSI can be used.
Intracytoplasmic sperm injection (ICSI) process
The head of the sperm is drawn into a needle and injected directly into the egg to achieve fertilisation.
What does in vitro refer to?
In vitro refers to the manipulation of organs, tissues and cells in a controlled artificial environment.
What do hormonal treatments stimulate
Hormonal treatments stimulates the development of multiple follicles
In vitro fertilisation treatment
(IVF) process
Ova are surgically removed from the ovaries using a hollow needle and then mixed with sperm in a culture dish.
The zygotes are then incubated until they have formed at least 8 cells and are then transferred to the uterus for implantation.
How can IVF be used in conjunction with pre-implantation genetic screening?
IVF can be used in conjunction with pre-implantation genetic screening to identify genetic disorders and chromosome abnormalities.
What does pre-implantation genetic screening tests ensure?
It ensures the most suitable embryos for insemination and implantation.
Contraception definition
The intentional prevention of conception or pregnancy by natural or artificial means.
What groups can contraception be organised into?
Contraception can be organised into 2 groups
- physical
- chemical
How do Physical methods of contraception work
Physical methods of contraception physically prevent fertilisation or embryo implantation.
What do physical methods of contraception include?
Barrier methods
Avoiding fertile periods
Intra-uterine devices
Sterilisation
How do barrier methods of contraception work?
Barrier methods use a device to physically block sperm from reaching the ovum therefore preventing pregnancy.
Examples of barrier methods of contraception
Male condom
Female condom
Diaphragm
Cervical cap
What is an intra-uterine device (IUD)
An IUD is a small T-shaped plastic and copper device that is inserted into the uterus.
How does an intra-uterine device (IUD) work and how effective are they
The IUD releases copper and prevents pregnancy for between 5 to 10 years. They are more than 99% effective at preventing pregnancy.
What is sterilisation
Sterilisation as an operation to permanently prevent pregnancy.
What does female sterilisation involve?
Female sterilisation involves cutting, tying or blocking the oviducts.
What does male sterilisation involve?
Male sterilisation involves cutting, tying or blocking the sperm ducts.
What is the oral contraceptive pill and how affective is it?
The oral contraceptive pill is a chemical method of contraception.
It is over 99% effective at preventing pregnancy.
What does the oral contraceptive pill contain
The oral contraceptive pill contains a combination of synthetic oestrogen and progesterone.

What do the synthetic hormones in the oral contraceptive pill do
The synthetic oestrogen and progesterone hormones mimic negative feedback, preventing the release of FSH and LH from the pituitary gland.
How does the oral contraceptive pill work
The oral contraceptive pill works by preventing ovulation. It also thickens the cervical mucus and thins the endometrium.
What does the progesterone only pill cause
The progesterone only pill, also known as the mini pill, causes the thickening of the cervical mucus.
What is the morning after pill and what does it do?
The morning after pill is a form of emergency contraception which prevents ovulation or implantation.
