School Science Lessons
Please send comments to: J.Elfick@uq.edu.au
Table of contents
10.7.0 "Natural" methods
10.7.3 "Rhythm method" of contraception
Contraception - Barrier methods
10.7.6 Condom, male latex condom, penis
10.7.5 Diaphragms and cervical caps
10.7.7 Female condom
10.7.4 Intra-uterine devices (IUDs)
Contraception - Chemical methods
10.7.8 Oral contraceptives
10.7.9.1 Depo-Provera contraceptive
10.7.9.2 Postinor-2, the "morning after pill"
10.7.13 WHO Guidelines on child birth
Contraception - Surgical methods of contraception
10.7.11 Tubal ligation
Contraception is the prevention of pregnancy as the result of sexual intercourse.
In developed countries, the method of contraception used is approximately as follows:
combined oral contraceptives pills (Combined O.C.) 36%, condoms 20%, diaphragms 2%,
interuterine devices (IUDs) 6%, natural family planning 16%, female sterilization 10%.
Some herbal preparations and antibiotics can decrease the effectiveness
of contraceptive methods that use hormones.
A recent survey of sexually-active girls, ages 15 to 19, in USA, July, 2016, showed the approximate use of birth control as follows:
Condom 85%, withdrawal 60 %, contraceptive pill 55%, emergency contraception 22%, Depo-provera injection 8%, fertility
awareness timing 8 %, hormone patch 2%, ring method 5%, interuterine device 2%, implant 2%.
For young adults, this is the only way to guarantee safety against pregnancy
and transmission of sexual disease.
It is best for young people to delay sexual intercourse until married to
a partner who is free of sexual disease and whom
they know will help to take care of any children born as a result of sexual
Withdrawal, "pulling out on time", coitus interruptus, is when the man
withdraws his penis from the vagina before he
Withdrawal is not a safe way to prevent pregnancy because some sperm may
be in fluid at the opening of the erect penis.
Even if the man ejaculates outside the vagina, some sperm may get inside
and cause a pregnancy.
Some men get too excited to withdraw the penis in time before ejaculating.
Also, with this method of contraception there is a risk of passing on STIs.
The following methods do not work as contraceptives: sexual intercourse
while standing up, putting things into the vagina after having
sex, e.g. cola, aspirins, taking a hot bath, Girls can get pregnant the
first time they have sex.
They do not have to have an orgasm, "climax", "come", to get pregnant.
The use of douches or spermicides inserted into the vagina after sexual
intercourse are unreliable methods of preventing pregnancy and
may be damaging.
10.7.3 "Rhythm method"
The rhythm method is also called the natural method, body temperature method,
natural birth control, fertility awareness, natural family
planning, Billings method, "safe period".
These methods help a woman to know the times in the month when she is most
likely to get pregnant.
This is done either by taking her temperature every day or by checking
the secretions on her vulva (the opening of the vagina).
These secretions vary from a sticky mucous to stretchy wet secretions.
During her fertile time, a woman who relies on natural methods only must
not have any penis / vagina contact.
Cycle lengths do not have to be regular for this method to be effective.
Some women find natural methods work for them but others consider these
natural methods are not very reliable contraception.
It is quite unreliable for teenage girls who have irregular menstrual cycles.
The method has no side effects and provides no protection against sexually
However, proponents of the above "method" have commented as follows:
The "Rhythm method" is a particular method of fertility regulation and
not a generic name, and therefore should not be used to describe
a group of individual methods, each having their own distinct guidelines
and rates of effectiveness.
A far more accurate title would be Natural Methods with individual listings
for Rhythm, Billings Ovulation Method, SymptoThermal,
and similar methods.
The use of the Billings name with the term Rhythm is largely outdated.
The failure to differentiate between distinct methods also fails to provide
sufficient information for a proper judgement to be made
regarding their suitability.
The Billings Ovulation Method has been scientifically validated and been
extremely effective in avoiding pregnancy in many studies
around the world.
From the earliest trials, the first being conducted by the World Health
Organization, method-related pregnancy rates were as low as 0-4%.
As teaching methods have been refined and improved, these rates have fallen
close to zero.
Proponents of the method who have conducted programs for training Billings
Ovulation Method teachers in developing countries claim
that when women hear this information they are very enthusiastic about
it and want to spread it to other women.
They say that the method is suitable for developing countries because:
1. There are no side effects the IUD very often causes prolonged inter-menstrual
bleeding, 2. It is inexpensive practically free,
3. Women with irregular menstrual cycles can safely use the method,
4. Trials have shown that its simplicity makes it suitable for all women,
including those who have had very little education,
5. It is commonly available because there are thousands of trained teachers
of the Billings Ovulation Method in countries around the world,
including the Philippines, China, India, most African countries, Timor
Leste, many South American countries and USA, UK and Europe.
6. It empowers women with the knowledge to manage their reproductive lives
to their own satisfaction.
7. Once a woman knows what is normal for her, her chart will alert her
to any abnormalities that should then lead to early medical treatment,
8. It is very effective either to avoid pregnancy or assist couples with
sub-fertility to conceive,
9. Once learned, the Method can be used right throughout the woman's reproductive
10. Sexual intercourse can occur only on "non fertile" days, assuming that
the woman has only one or two fertile days per month.
So while this method is natural the woman must make a very accurate determination
about when she has fertile days and use self control.
Fertility days tracked with urine samples is much more accurate than using
body temperature cycles and subtracting 15 days from the expected date of
The iPhone Menstrual Period Tracker allows women to use the internet to
keep track of their fertility status.
10.7.4 Intra-uterine device
See diagram 9.25.6: Barrier methods
An IUD or IUCD, is an intrauterine contraceptive device made of plastic
or metal, usually copper, inserted into the uterus.
It prevents the fertilized ovum implanting in the wall of the uterus, but
how it does this is not well understood.
To get it fitted a woman must visit a doctor or family planning clinic.
It can remain in position for a long time but it can fall out by itself.
A doctor or a health worker should check that it is properly inserted and
remains in place.
An IUD can be left in place for up to five years and it nearly always stops
the woman getting pregnant.
The IUD is not suitable for women who experience pain or discomfort when
it is inserted and in place.
IUD users may experience heavier periods with more cramps.
Pelvic infection caused by IUD use can lead to future infertility.
A doctor or a family planning clinic worker should show women how to check
each month to see if the IUD is still in place.
When an IUD is removed, the woman can usually to get pregnant immediately.
Nowadays, the plastic and exposed copper surface Multiload IUD (Cu-375)
is preferred to Copper 7 (Cu-7) Nova T and T Cu-200
The IUD is a very effective contraceptive but it will not protect against
sexually transmissible diseases, e.g. Chlamydia and gonorrhoea.
Some doctors do not prescribe it because of the danger of inflammatory
reactions and even Pelvic Inflammatory disease (PID).
Women using the IUD need never worry about forgetting to take it.
Nuvaring is a soft plastic ring containing oestrogen and progesterone to
be inserted into the vagina each month to supply contraception
for three out of four weeks per month.
It is an expensive method of contraception.
10.7.5 Diaphragms and cervical
A diaphragm is a soft rubber cap with a metal spring, shaped like a hemisphere,
that fits against the wall of the vagina near the cervix,
neck of the uterus.
It should be applied with a chemical spermicide.
A new diaphragm of the right size must be fitted by a doctor or a family
Then the woman must be taught how to use it so that she can insert it herself
each time she needs to use it.
Diaphragms must be used every time a woman has sexual intercourse.
It can be inserted at any convenient time beforehand.
It should be taken out about eight hours after intercourse, washed with
warm soapy water, dried with a towel and kept in a clean safe
Be sure to read and follow all the instructions on the packet.
Diaphragms must be placed inside the vagina to cover the cervix each time
a woman has sexual intercourse so the man's sperm cannot
Women should check the size again after a pregnancy, a vaginal operation,
or if they feel the fit has changed and the diaphragm feels
loose in the vagina or is uncomfortable.
A cervical cap is a dome-shaped barrier made of soft rubber or silicone
that can be fitted closely over the cervix.
They should remain in place after sexual intercourse for about eight hours
then washed, as with a diaphragm.
It should be replaced after two years.
Both diaphragms and cervical cups are vaginal barrier contraceptives that
prevent the sperm from contacting the ovum.
To ensure that no sperm can pass them they should be inserted with some
water-based lubricant and some spermicide that kills sperm.
Spermicides can be purchased as creams, jellies, and foams.
They must be placed inside the vagina before a couple has sexual intercourse.
Spermicide creams, foams and jellies are not effective contraceptives on
They should be used with a diaphragm or condom.
However, women should not rely on this protection by itself, a condom should
Some women and men do like spermicide cream because they think it is irritating
or messy or smelly.
10.7.6 Condom, male latex
| See diagram 9.25.1: Condom 1 and 2
| See diagram 9.25.2: Condom 3 and 4
| See diagram 9.25.3: Condom 5 and 6
| See diagram 9.25.4: Condom 7 and 8
Researchers at King's College London reported in the British Journal of
Urology they had used 17 studies of more than 15, 000 penis
size measurement across all ages and races and found the average length
was 9.16 cm when flaccid and 13.12 cm when erect.
A condom is a sheath, usually made of latex rubber, that fits over the
erect penis during sexual intercourse.
It must be rolled on to the man's penis before it is put into the woman's
It collects the man's sperm in a bulb-shaped reservoir at the end and prevents
the sperm from entering the vagina.
Condoms should have a complete close fit on the erect penis.
The most common reason for condom failure is improper use so read the instructions
on the packet and follow them.
Check the expiry date on the packet.
A new condom must be used each time a couple has sexual intercourse.
Never use two condoms at the same time.
Use plenty of water-based lubricant to ensure that the condom will not
Never use petroleum jelly, Vaseline, baby oil, or hand lotion as a lubricant
because these substances weaken the latex rubber so much
that the condom may break during intercourse.
Coconut oil can be used as a sexual lubricant, but not for lubricating
Use a spermicide cream or jelly in the vagina to kill any sperm that may
Never use plastic film instead of a condom.
Store condoms in a cool, dry place.
Do not store them in the glove compartment of a car because heat damages
Men should be prepared by carrying new condoms with them if they think
they will need them.
However, condoms may be damaged if carried in a wallet or pocket for a long
Make sure the condom is not too old by checking the expiry date on the
Male latex condoms may be up to 95% effective for preventing pregnancy
and the transmission of sexually transmitted infections.
However, condoms can break during intercourse and they only protect the
immediate area they cover and so may not protect against
infection with genital herpes or genital warts.
Some people are allergic to latex.
How to use a condom
Men have to get used to using condoms.
If they have never used a condom for sexual intercourse, they should practise
putting them on and taking them off in private.
1. Open the packet very carefully with the fingers, not with scissors.
2. Make sure the condom is the right way on, so it rolls down easily.
3. Squeeze the air out of the bulb-shaped reservoir at the tip of the condom
so that it is empty.
4. Keep hold of the tip (reservoir) of the condom, then unroll the condom
down to the base of the erect penis before starting sexual
Put some water-based lubricant, e.g. "K Y Jelly", outside the condom to
make sure it will not break.
5. During sexual intercourse, check that the condom is still on.
6. Immediately after ejaculating, hold the condom firmly and withdraw the
penis while it is still erect.
When removing the penis from the vagina, the condom must not come off the
penis or tear and leave sperm in the vagina.
7. After removing the condom, wipe the rest of the semen from the penis
with a tissue.
8. Carefully wrap the used tissue and condom in paper and dispose of it
in a plastic bag.
Put it in the rubbish tin, not down the toilet.
Use latex condoms throughout sexual activity.
Condoms can be purchased at any drug store, but if for some reason you
are too embarrassed or do not feel like driving, you can
purchase condoms online in a few clicks.
Undercover Condoms is one
site that makes buying condoms simple and easy in the comfort of your own
Use only water-based lubricants.
Lubricants are another item that can be easily purchased at the drug store,
however if for some reason
you would prefer to order them online there are plenty of places.
Do not share your towel or underwear with anyone.
The WebMD website shares commonly overlooked
prevention tips like this one and more.
When it comes to STDs it is better to be safe than sorry, so make sure
to check this site out.
Wash before and after intercourse - Centers for Disease Control and Prevention
is a great STD resource to check out.
CDC gives you tons of great hygiene tips for STD prevention that are simple
and can be incorporated into your everyday routine.
10.7.7 Female condom
Female condoms were made of polyurethane, but are now made of nitrile,
They are designed to be inserted into the vagina and stay in place during
They are not easy to insert and may make distracting noises during sexual
However, a woman can insert them at a convenient time long before sexual
By contrast the male has to wait until the penis is erect before using
the male condom
As they are not made of natural latex rubber, oil-based lubricants can
They are still much more expensive than the male condom but they are a fairly
effective barrier to pregnancy and STIs.
10.7.8 Oral contraceptives
See diagram 9.25.7: Oral contraceptives
Oral contraceptives are also called the contraceptive pill, "the pill",
birth control pill, hormonal birth control, emergency contraception,
morning after" pill.
The contraceptive pill came as a result research on the use of hormones
in contraception by Gregory Pincus, working with John Rock
in Puerto Rico.
The first actual pill was created by Carl Djerassi in Mexico City.
They contain synthetic female sex hormones, either progesterone or combined
progesterone and oestrogen.
Oestrogens are steroid hormones from the ovary or uterus that stimulate
changes during the oestrous cycle and develop female
The oestrogen in contraceptive pills may be ethinyl oestradiol,
Synthetic progesterone is called progestin, levonorgestrel (norgestrel),
C21H28O2, with action similar to progesterone
Oestrogen hormone blocks ovulation so no egg is released from the ovary
and thickens the cervical mucus so it is difficult for the
sperm to contact the egg.
Oestrogen may produce side effects, e.g. weight gain, blood clots.
Progesterone hormone blocks the normal menstrual cycle and prevents implantation
of a fertilized ovum in the uterus wall by thinning
the lining of the uterus.
The pills must be taken every day for three weeks and then not taken for
one week when menstruation occurs.
The combined oral contraceptive pill (combined O.C.) contains both oestrogen
and progesterone and is no longer used for emergency
It stops ovulation occurring so it stops the woman's ovaries from releasing
an egg each month.
Some women taking the pill may experience side effects, e.g. nausea or
They should report any side effects to a doctor.
The progesterone-only pill, "mini pill" contains only progesterone.
It works differently from the combined pill by changing the mucus at the
cervix the opening into the uterus so sperm cannot get through
and meet the egg.
It has less side effects but it is not as safe to prevent pregnancy.
Both pills are very effective contraceptives, but they will not protect
against STIs or AIDS.
Some women cannot take oral contraceptives because they are heavy smokers
or have high blood pressure or are taking other
A study published in 2010 of 40.000 women followed for 40 years concluded
that women who take "the pill" are less likely to die from
any cause, including cancer and heart disease but some women still question
whether the health risks outweigh the benefits.
This hormone pill is usually taken every day for 21 days with a break of
Side effects may include headaches, weight gain, loss of libido, breast
tenderness, mood changes and anxiety.
Some women switch to other methods after some years of using oral contraceptives
because they tire of taking pills almost every day
and prefer a more "natural" method of contraception.
10.7.9.1 Depo-Provera contraceptive
Depo-Provera, depot medroxyprogesterone acetate, C24H34O4,
(DMPA), is a type of injectable synthetic hormone that is similar to
progesterone and is part of the natural menstrual cycle.
After injection deep into the muscles of the back or buttocks its contraceptive
effect lasts for three months.
After ceasing its use it might take nine months to get pregnant.
It prevents pregnancy by preventing ovulation and by thinning the lining
of the uterus and preventing the growth of a fertilized egg.
In early stages of using Depo-Provera a change in the menstrual cycle occurs.
After two or three injections most women will have no periods at all.
Depo-Provera is a very effective form of contraception.
There is none of the risk of forgetting to take it.
It can reduce the risk of cancer of the ovary and womb, thrush and pelvic
inflammatory disease (PID).
However, it gives no protection from STIs and it introduces chemicals into
Up to 2% of women report long-term side effects, e.g. erratic and excessive
bleeding, weight gain and reduced periods.
This method is comparatively expensive.
"Implanon" is a 4 cm x 2 cm plastic rod to be inserted under the skin of
the upper arm to release progesterone and provide
contraception for up to three years.
It may cause periods to change pattern and length.
10.7.9.2 Emergency contraceptive
ECPs are for emergencies, e.g. unprotected sexual intercourse, broken condoms,
date rape, forced sexual intercourse, and
should not be used as a regular form of female contraception.
In some countries ECPs are called EHCs, emergency hormonal contraceptives.
The two main ECPs are 1. Progestin only, e.g. "Postinor" and 2. progestin
antagonist (RU-486), e.g. "Mifeprex".
1. Progestin only ECPs, containing levonorgestrel
is said to be up to 90% effective up to 72 hours after intercourse.
Brands include "Norlevo", "Postinor"
Postinor, the "morning after pill"
Postinor Tablets, the "morning after pill", is a brand of medicine containing
the active ingredient levonorgestrel, C21H28O2,
progesterone only contraceptive.
The term "morning after" is a misnomer because this emergency contraceptive
if most effective within 12 hours after sexual intercourse.
Postinor is an emergency contraceptive only and is not intended as a regular
method of contraception.
It is used to prevent pregnancy when taken within 72 hours of unprotected
It will not prevent you from catching sexually transmitted diseases.
Ask your doctor or pharmacist if you have any questions about why you are
Consult your doctor before you take it if you have diabetes mellitus, ischaemic
heart disease, have suffered a stroke, have had breast
cancer, have severe liver disease
Do not take Postinor if you are pregnant, have previously had unprotected
intercourse more than 72 hours earlier in the same
menstrual cycle, as you may already be pregnant, are experiencing vaginal
bleeding, have breast cancer.
Do not take Postinor after the expiry date printed on the pack or if the
packaging is torn or shows signs of tampering.
Take the first tablet no later than 72 hours after intercourse.
Take the second tablet exactly 12 hours after the first tablet.
There is only limited information available on Postinor when taken by women
aged 14-16 years and no information on its use in
younger women or children.
Mifepristone, RU-486, C29H35NO2,
is a progestin antagonist that inhibits progesterone to induce bleeding during the luteal phase and
during the first seven weeks of pregnancy by releasing endogenous
prostaglandins from the endometrium or decidua.
Mifepristone competitively binds to the progesterone receptor, resulting in inhibition of the effects of endogenous or exogenous progesterone.
Brand names include "Mifeprex" in USA.
So it is an "abortion drug" and cannot be purchased in a pharmacy except for a few countries, including China and India.
In some countries, doctors must be authorized to use mifepristone.
Mifepristone is used by doctors in combination with a type of prostaglandin called misoprostol which causes the uterus to contract and
so to assist the expulsion of pregnancy tissue.
Mifepristone is also a glucocorticoid receptor antagonist and has been used to treat high levels of the hormone cortisol in patients with
nonpituitary cushing syndrome.
See diagram 9.25.8: Vasectomy
Vasectomy is a method of male sterilization.
It is not castration.
The vas deferens connecting the testis to the urethra is cut and tied.
It is safe method that does not affect sexual activity.
When a vasectomized man ejaculates during sexual intercourse, the semen
is still ejaculated but it contains no sperm.
Vasectomy must be done by a doctor under local anaesthetic in the doctor's
Usually, the operation is not reversible.
People who have been sterilized should still use condoms if there is any
risk of STIs.
Doctors advise two sperm tests during the three months after the operation
to check that no sperm is still contained in the ejaculate.
10.7.11 Tubal ligation
See diagram 9.25.5: Tubal ligation
Tubal ligation, "tubes tied", is a method of female sterilization where
the fallopian tubes are clipped or cut and the cut ends tied.
A more modern method called tubal occlusion closes the lower half of the
This method is irreversible.
If the operation is done correctly, the woman can never become pregnant
The Fallopian tubes that carry eggs to the uterus are blocked by surgical
procedure done by a doctor, usually in a hospital.
Conception occurs in two stages, fertilization then implantation.
Abortion terminates pregnancy by removing the implanted foetus before it
can survive outside the uterus.
In most countries only qualified medical staff can legally do abortions.
Many people and religious groups strongly oppose abortion on ethical and
They may believe that foetus has the rights of a living person so abortion
is a form of murder.
Other people, e.g. "Pro choice" groups, believe that it is a woman's
right to choose when to become pregnant.
The medical procedure is quick and safe if done by a competent doctor.
However, some women feel guilty and depressed after the abortion.
Most women do not suffer from any long-term physical consequences.
Abortion in the first 14 days after conception, interception, is done with
a syringe to removes the content of the uterus.
It is a quick and reasonably safe method.
However, some doctors prefer to delay the operation until they can be more
sure of achieving a successful abortion.
Abortion up to 14 weeks after conception is done with a suction machine
that draws out the contents of the uterus.
Abortion 14 to 18 weeks after conception is done by stretching the cervix
and the removing the contents of the uterus.
This method is called dilation and evacuation, "D and E" (dilation and
curettage, "D and C") and is very safe.
The drug RU486 is very effective for emergency abortions.
Abortion 18 to 20 weeks after conception, is done by injections to cause
contractions that push out the contents of the uterus.
This form of "later termination" is rare because it is dangerous if uncontrollable
bleeding from the uterus occurs.
Another procedure to terminate a late pregnancy involves cutting through
the abdomen and the wall of the uterus to remove the
However, it is also a dangerous procedure and it may cause a scar that
interferes with later pregnancies.
10.7.13 WHO Guidelines on child birth
World Health Organization, New recommendations to establish global care standards for healthy pregnant women and reduce
unnecessary medical interventions.
15 February 2018 (edited)
Worldwide, an estimated 140 million births take place every year and most of these occur without complications for women and their babies.
Yet, over the past 20 years, practitioners have increased the use of interventions that were previously only used to avoid risks
or treat complications, such as oxytocin infusion to speed up labour, or caesarean sections.
"We want women to give birth in a safe environment with skilled birth attendants in well-equipped facilities.
However, the increasing medicalization of normal childbirth processes are undermining a woman's own capability to give birth and
negatively impacting her birth experience," says WHO Assistant Director-General for Family, Women, Children and Adolescents.
If labour is progressing normally, and the woman and her baby are in good condition, they do not need to receive additional interventions
to accelerate labour," she says.
Childbirth is a normal physiological process that can be accomplished without complications for the majority of women and babies.
However, studies show a substantial proportion of healthy pregnant women undergo at least one clinical intervention during labour and birth.
They are also often subjected to needless and potentially harmful routine interventions.
The new WHO guideline includes 56 evidence-based recommendations on what care is needed throughout labour and immediately after
for the woman and her baby.
These include having a companion of choice during labour and childbirth; ensuring respectful care and good communication between women
and health providers; maintaining privacy and confidentiality; and allowing women to make decisions about their pain management, labour
and birth positions and natural urge to push.
Every labour is unique and progresses at different rates.
In a first labour, it usually does not extend beyond 12 hours, and in subsequent labours it usually does not extend beyond 10 hours.
The previous benchmark for cervical dilation rate at 1 cm/hr during the active first stage of labour may be unrealistic for some women
and is inaccurate in identifying women at risk of adverse birth outcomes.
A slower cervical dilation rate alone should not be a routine indication for intervention to accelerate labour or expedite birth.
Health professionals should advise healthy pregnant women that the duration of labour varies greatly from one woman to another.
"Many women want a natural birth and prefer to rely on their bodies to give birth to their baby without the aid of medical intervention," says WHO Director,
Department of Reproductive Health and Research.
Even when a medical intervention is wanted or needed, the inclusion of women in making decisions about the care they receive is important
to ensure that they meet their goal of a positive childbirth experience.
Unnecessary labour interventions are widespread, often putting a strain on already scarce resources and further widening of the equity gap.
As more women give birth in health facilities with skilled health professionals and timely referrals, they deserve better quality of care.
About 830 women die from pregnancy-related or childbirth-related complications around the world every day, but the majority could be prevented
Disrespectful and non-dignified care is prevalent in many health facilities, violating human rights and preventing women from accessing
care services during childbirth.
Often, the health provider controls the birthing process, which further exposes healthy pregnant women to unnecessary medical interventions
that interfere with the natural childbirth process.
Achieving the best possible physical, emotional, and psychological outcomes for the woman and her baby requires a model of care in which
health systems empower all women to access care that focuses on the mother and child.
While most women want a natural labour and birth, they also acknowledge that birth can be an unpredictable and risky event and that close
monitoring and sometimes medical interventions may be necessary.
Even when interventions are needed or wanted, women usually wish to retain a sense of personal achievement and control by being involved
in decision making, and by rooming in with their baby after childbirth.
For further information, please contact: