Types of Birth Control
Types of birth control
- Birth control methods are important in keeping family sizes small and in limiting the increase in human population
- Humans can use mechanical, chemical, surgical and natural contraceptive methods to prevent a pregnancy
- Some birth control methods also give protection from sexually transmitted infections
Natural
- Abstinence
- avoiding sexual intercourse completely
- Rhythm method
- avoiding sexual intercourse during the fertile period of the menstrual cycle when ovulation occurs
- the exact time ovulation happens can be worked out by monitoring body temperature and quality of cervical mucus
- this is the least reliable method of birth control
Chemical
- IUD / IUS
- an intrauterine device or intrauterine system is a small device fitted inside the uterus by a doctor or nurse
- it releases sex hormones which thicken the mucus produced in the cervix, making it difficult for sperm to swim into the uterus
- it also thins the lining of the uterus, making it more difficult for a fertilised egg to implant
- an IUD also interferes with passage of sperm through the uterus, in which way it is acting as a barrier method of birth control
- Contraceptive pill, implant, injection
- may contain just progesterone or a mixture of progesterone and oestrogen
- very effective when taken regularly
- the hormones can also be delivered from a small skin implant or an injection, both of which last several months and increase the effectiveness as they remove the risk of forgetting to take a pill regularly
Barrier
- These all work by preventing sperm from reaching the egg
- Condom
- latex sheath worn over the penis
- prevents sperm entering the vagina as ejaculate remains in condom
- also protects against STIs
- Femidom
- latex sheath inserted into the vagina
- prevents entry of sperm into the vagina
- Diaphragm
- a rubber cap that fits over the entrance to the cervix
- prevents entry of sperm into uterus
- often used with a spermicide (cream which kills sperm)
Surgical
- Vasectomy
- the sperm ducts are cut, meaning that no sperm is present in the semen when ejaculation occurs
- very effective but difficult to reverse
- Female sterilisation (tubal ligation)
- the oviducts are cut or tied off, preventing eggs from reaching the uterus or sperm from reaching the eggs
- very effective but difficult to reverse
How do Contraceptive Hormones in the Pill Work?
- They work by mimicking some of the hormone levels during pregnancy
- By raising the levels of progesterone and oestrogen, the uterus lining is maintained and development of another egg cell is prevented
- This means that sex at any time of the month cannot cause pregnancy as no egg is released to be fertilised
Fertility Treatments
- In situations where couples find it difficult to conceive, fertility treatments can improve their chances
- There are several different options, depending on what the fertility issue is
Artificial Insemination (AI)
- If the male is not producing healthy sperm, donor sperm can be used
- The sperm are placed into the female’s vagina at the fertile point in her menstrual cycle
- Social issues to consider include:
- The male must be able to cope with the fact that the child is not biologically his
- Sperm donors may father multiple children who are not able to know their parentage
Fertility Drugs
- This method is used when the female is not producing enough eggs
- Hormones, including FSH, are given to her to stimulate egg production
- Social issues to consider include:
- Several eggs can be released at once so this increases the chance of multiple births (twins or triplets etc)
In Vitro Fertilisation (IVF)
- If the female cannot conceive naturally even after taking fertility drugs, or if there are issues with both male and female fertility in a couple, IVF can be used
- This involves fertility drugs being given to the female to stimulate egg production before they are harvested from the ovary
- The eggs are then inseminated in a petri dish using sperm from the male (‘in vitro’ means ‘in glass’) and, once embryos have formed, they are placed back into the uterus of the female
- Several embryos are implanted to increase the chance of one developing further
- Social issues to consider include:
- IVF is relatively expensive and not all couples can afford it
- As several embryos are implanted, the risk of multiple births is quite high
- Some women use IVF to get pregnant at a later age than they would be able to conceive naturally
