STI's and Contraception Flashcards
basic strategies of Contraception
Preventing the production of ova or sperm
Preventing fertilisation of the ovum
Preventing implantation
Abstinence
Contraceptive pills
contain varying proportions of estrogen and progesterone.
Estrogen-based pills send false messages to the brain and prevent ovulation.
Progesterone-based pills cause a mucus plug to form in the cervix, thus preventing sperm from entering the uterus.
vasectomy
vas deferens can be cut, thus preventing sperm leaving the testes.
Sperm production continues but the sperm are broken down and are reabsorbed by the body.
After a vasectomy men can still ejaculate (seminal fluid only) and continue to produce testosterone (it does not affect their sex drive).
In some cases, a vasectomy can be reversed.
tubual litigation
In females, the Fallopian tubes are cut or sealed thus preventing fertilization.
Ovulation and menstruation continue after the operation and sex drive are not affected.
In some cases a tubal ligation is reversible.
natural methods
Coitus interruptus – the man withdraws before ejaculating.
Douching – washing out the vagina after intercourse.
Ovulation or rhythm method – a woman calculates her ‘safe’ period based on her body temperature and appearance of vaginal secretions.
mechanical barrier methods
- Male and female condom
- Cervical cap
- Diaphragm
- Vaginal sponge
These devices are moderately effective, especially if used in combination with a chemical barrier, such as a spermicide.
Only the male condom offers protection against the transmission of STIs.
98% effective
Intra- uterine device (IUD)
IUDs are small T-shaped plastic devices inserted into the uterus by a doctor.
Modern IUDs contain either copper or hormones which prevent fertilisation.
The IUD itself prevents implantation.
IUDs can be left in place from 5 to 10 years.
IUDs are an effective form of contraception.
Copper IUDs can be used as a ‘morning after’ device if there is
99% effectve
Morning after pill
The ‘morning after pill’ can be used in emergency situations up to 72 hours after intercourse if there is a risk of an unwanted pregnancy.
These drugs contain high levels of estrogen and/or progesterone which prevent implantation.
The so called ‘abortion pill’, RU-468 blocks the production of progesterone needed to sustain a pregnancy.
Pathogens responsible for STI’s
Viruses - e.g. genital herpes, genital warts
Bacteria – e.g. gonorrhea, syphilis, chlamydia
Protozoa – e.g. trichomoniasis
Parasites – e.g. pubic lice
Symptoms of syphilis
Syphilis, if untreated, passes through several stages that occur over many years.
1st stage – a sore or chancre appears near site of infection.
2nd stage – rash & prolonged flu-like symptoms before entering long, silent period (often several years).
3rd stage – virus eventually attacks bones, heart & nervous system often leading to insanity & death.
Symptoms of Gonorrhoea
Males – In 20% of cases there are no symptoms. Remainder suffer discharge of pus from penis and experience pain urinating.
Females – 10-15% experience symptoms similar to those of men. Majority have no symptoms but all may suffer serious health problems such as pelvic inflammatory disease and infertility.
Symptoms of Chlamydia
Chlamydia infections show symptoms similar to those of gonorrhea.
Syphilis, gonorrhea & chlamydia infections can usually be treated with antibiotics, though antibiotic resistant strains of the pathogens are appearing.
As with all STIs, use of a male condom during sexual activity prevents the transmission of bacterial pathogens.
Genital herpes
Genital herpes is usually caused by the virus, Herpes simplex 2 – a strain closely related to Herpes simplex 1, the virus responsible for cold sores.
Once infected the virus remains in the body. Although the symptoms can be treated, there is no cure for herpes
Some people experience a single episode of herpes – in others it is recurrent.
Not all people infected with the herpes simplex virus display symptoms but may be able to pass on the infection.
For those who display symptoms, the herpes virus causes painful blistering, usually around the genitalia.
Active sores are usually the source of infection.
No known long-term health problems associated with a herpes infection.
Herpes infection in newborn babies
Mothers who are infected with herpes in the last trimester of a pregnancy are at risk of infecting their baby during birth.
More than 40% of newborn babies infected with herpes die or have severe brain damage.
A Caesarean section is generally performed if the mother is suspected of having a herpes infection.
Genital warts
Genital warts are caused by the human papilloma virus (HPV).
generally appear around the external genitalia, though they can also be internal (especially in women).
External warts can be removed using laser or anti-wart ointment.
The papilloma virus is responsible for 70% of the cases of cervical cancer in women.
