The Ins and Outs of Contraceptives

Hopefully your understanding around conception and contraception goes further than Coach Carr’s PE lesson on Mean Girls “Don't have sex, because you will get pregnant and die! Don't have sex in the missionary position, don't have sex standing up, just don't do it, OK, promise? OK, now everybody take some rubbers.”

In reality however, often we are a bit clueless to how a baby is made and how the contraceptive methods we are offered or familiar with by name actually work. Even our well-meaning GP’s can skip over fully explaining the methods that they suggest. So, in continuing with MWK’s aim to create informed parents who can be confident in their decision making, this episode I go into some of the many contraceptive methods available – how they each specifically work, how effective they are and some common side effects that come with them.

Listen in to get the full run down, otherwise here’s a bit of what the episode covers…

Firstly, to understand contraception, you need to understand the basics of conception. If as a child you never asked the question “how is a baby made” or you just never got a straightforward answer, thanks mum and dad, here’s my simple conception explanation…

Basically, each month as part of their menstrual cycle, women release an egg from one of their ovaries into a fallopian tube (the passageway to the uterus). During sex, ejaculation causes sperm from the man to enter the woman, travel up through the vagina, the cervix, the uterus and then into the fallopian tubes where, if timed correctly it can meet up and join with the woman’s egg – this process is called fertilisation. The fertilised egg then travels into the uterus, implants on the internal lining and begins to grow.

In order to avoid this happening, contraceptive methods exist.

Now not all contraceptive methods work in the same way. Many expect that a contraceptive means that conception, as I just explained, doesn’t happen. However, this isn’t the case for all options. Generally speaking, there are three different ways that contraceptives work:

- Preventing eggs being released from ovaries

- Preventing the released egg from meeting with a sperm

- Preventing an embryo, or fertilised egg from implanting into the uterus (which if we look back to my explanation of conception, technically in this case conception has occurred, the fertilised egg is just prevented from growing or developing any further due to the fact in cant implant in the uterus). This third option is where some people may have ethical or moral objections if they believe human life begins when the egg and sperm meet.

So let’s get into the specifics:

Natural methods:

- Natural methods of contraception are based on the idea that a woman learns to monitor her menstrual cycle and is able to recognise her fertile period in order to avoid unprotected sex during that time each month. There are a range of techniques women use to monitor when she is fertile, but this method of contraception is most reliable in women who have very regular periods. Methods of tracking include the calendar or rhythm method, changes to cervical mucous, monitoring your body temperature every morning (it should be increased after ovulation), among other techniques.

This method as a contraceptive, if done perfectly can be 75-95% effective however, it’s been shown that 25% of women who choose natural methods of contraception end up pregnant. I definitely have a number of friends who have fallen pregnant whilst using some of these timing methods, so it’s worth noting that natural methods as the stats prove, can be very effective but require a lot of motivation and knowledge of your own body to be reliable.

· Another natural method that also follows this idea of tracking your menstrual cycle is the withdrawal method where the man pulls out before ejaculating with the idea that no sperm enter the vagina. It’s a bit of a risky contraceptive due to the fact that pre-ejaculate can contain sperm, and it relies on the man pulling out in time. Approximately 20% of women get pregnant using this method and family planning NSW do not recommend withdrawal as a reliable form of contraception.

· Breastfeeding – Some women are told that when breastfeeding you can’t fall pregnant and so they use this as their natural method of contraception. I’ve fleshed this out further in episode 6 ‘Is Breast Best pt1’, but basically yes, breastfeeding does normally result in what’s known as amenorrhoea (no period) due to the hormones released as a baby feeds. However, every woman’s experience and timing of this period-free zone is different, and ovulation occurs prior to bleeding each month, which can mean that you fall pregnant before you even know your period has returned. So, breastfeeding is often not recommended as a contraceptive method on its own.

Barrier Contraceptives:

- These are made up of physical barriers that stop the sperm from getting anywhere near the egg and are therefore effective prior to fertilisation.

· Male condom – I’m sure most people know what a condom is, but it basically sits over the male’s penis and catches the semen during ejaculation, meaning nothing enters the woman’s vagina, cervix or goes anywhere near an egg. Reliability is based on correct use eg. making sure condom is in date, has no holes and isn’t used in combination with oil-based lubricants. If used perfectly, condoms are 82-98% effective however condoms are often not used properly and approximately 20% of women will still get pregnant when using condoms as their only contraceptive.

· Female condom – less common and basically looks like a polyurethane pouch with rings which help it fit loosely inside the vagina. It also stops sperm going through the cervix. When used as designed they are 79-95% effective however due to user error it is estimated that 20% of women will still get pregnant using the female condom.

· Diaphragm – soft silicone cup that is inserted in the vagina to stop sperm from entering the cervix and uterus. A diaphragm initially needs to be fitted but can then be inserted and removed as needed and can last for up to 2 years. Similarly to both the male and female condom, if used perfectly it is 88-94% effective, however it seems that 20% of women are still getting pregnant using the diaphragm.

Hormonal Contraceptives:

- Hormonal contraceptives can be broken down into combined progesterone and oestrogen or progesterone only options. If breastfeeding, it is recommended not to have oestrogen as it can decrease milk supply, so the progesterone only options are the way to go if wanting a hormonal contraceptive.

· The oral/combined contraceptive pill (OCP) – aka “the pill,” this tablet contains small doses of both progestin and oestrogen in varying strengths depending on the specific brand. Basically, the pill is taken daily for three weeks and then a week of either sugar pills, or no pill follows where a withdrawal bleed occurs. There are three ways the OCP works: Firstly, and simply put, the hormones act in a way that prevents an egg from developing or being released from an ovary, so basically there is no egg to fertilise. Then secondly, the OCP also changes the cervical mucous which reduces sperms ability to actually make it through the cervix and up the regular pathway to the fallopian tubes. And then if these first two steps haven’t worked, thirdly the OCP also causes changes to the lining of the uterus which makes it thin and stops an embryo from implanting. The OCP is 99.7% effective if taken correctly, however 9% of women taking the pill may still get pregnant. Failure is most often linked to either the woman forgetting to take the pill, being sick with vomiting or diarrhoea, or having had medication like antibiotics which can affect the absorption of the OCP. The pill is also often prescribed to help with acne or heavy periods so is a very common choice of contraception as a lot of women start taking it as teenagers.

· Progestin only pill – aka the “mini pill”, is a contraceptive which contains a very low dose of progestin and acts by thickening cervical mucous, thinning the uterine lining and suppressing ovulation. Yes, these are the same effects as the OCP however the order I’ve said them in is significant… Because the dose of progestin is so low, it is not very reliable at suppressing ovulation or completely blocking the sperm from entering due to the changes in cervical mucous. This means that sometimes the effectiveness of the mini pill is down to the thinning of the uterine lining, which means a fertilised egg cannot implant and continue growing. The reason I’ve explained this so specifically here, is that this is where some people may have an ethical or moral objection to this type of contraceptive because you believe that life begins at fertilisation. As a side note, the mini pill is more successful in ovulation suppression when combined with exclusive breastfeeding. And to ensure it is most effective, it needs to be taken at the same time every day as it loses its contraceptive effect rapidly after 24 hours.

· Injections – there are both combined hormone injections or progestin only injections. The combined is as it suggests both progesterone and estrogen and requires administration monthly. The progestin only is an intramuscular injection given 2 or 3 monthly depending on the brand. Both work by supressing ovulation, increases the consistency of cervical mucous and thinning the lining of the uterus. Again, because ovulation is suppressed there is no egg to fertilise and thus the cervical mucous and uterine lining changes are back-ups really. The injection if administered on time is more likely to be effective than a pill, due to the fact that it travels through the blood stream not the gut, and it doesn’t rely on women remembering to take a pill every day. Some women find that whilst using the injections their period stops completely and it’s also worth knowing that you can experience a short delay in return to fertility when stopping the injections.

· Extended cycle or continuous pills are available which are a combined hormonal and basically delay the sugar pill period to once every three months or more – these are most often used for women who have endometriosis and other issues with symptoms during their cycle

· Implants – for example the Implanon is a plastic rod that is inserted under the skin in your arm by a doctor which continuously releases progestin over a three year period. It causes thickened cervical mucous, supressed ovulation and some small changes to the uterine lining. It is super reliable (like 99.9% effective) due to the fact that it’s done once and doesn’t have to be thought of again for another few years. Women often find their pattern of bleeding changes with an Implanon, with 1 in 5 women experiencing irregular or persistent bleeding, and others experience no bleeding at all.

· Patch – combination of progestin and estrogen worn on your skin. A new patch is put on weekly for three weeks and then in the fourth week no patch is worn. It works in the same way the OCP works.

· Vaginal ring – Nuvaring is a soft flexible ring that is inserted in the vagina monthly. It remains inside for 21 days and is then removed for 7 days for a withdrawal bleed before replacing with a new ring. It slowly releases both estrogen and progestin hormones which are absorbed through the vaginal lining. It works similarly to the OCP.

Intrauterine Devices (IUDs):

- An IUD is a small, usually T-shaped device that is placed inside the uterus by a healthcare worker which provides contraceptive effect for a number of years. It is not clearly understood how exactly IUDs work however it is believed that an inflammatory reaction occurs due to the body responding to the IUD as a foreign object where it tries to destroy it. IUDs are known to reduce the rate of egg fertilisation as well as causing the lining of the uterus to thin and thus prevents an egg, if fertilised from implanting and developing. IUD’s are 99.8% effective and are a good option for long term contraception as they cover about 5 years. There are two types of IUD’s:

· Copper IUD – is a plastic device which has copper wrapped around its stem. As a non-hormonal IUD option, the copper works as its toxicity damages the egg and sperm, decreasing their ability to meet and become an embryo. As a side effect to point out, some women will find their period actually becomes heavier with the copper IUD.

· Hormonal IUD – eg. Mirena – has a cylinder containing a progesterone hormone around the stem of the device which is slowly released. Similar changes occur to the cervical mucous and lining of the uterus as in progesterone only pill however the dose of progesterone is not enough to suppress ovulation which means an embryo can form. The main way the hormonal IUD works is by damaging both the sperm and egg so that fertilisation is unlikely to occur, however if an embryo has formed, the IUD lowers the chance of the embryo surviving.

A benefit that often comes with the Mirena is that it reduces menstrual bleeding which is why a lot of women who have heavy or long periods choose this as their preferred contraceptive.

Some things to consider with an IUD is that it can expel itself from the uterus, so checking that the string is present in the vagina is recommended. It is also possible, but rare, to fall pregnant with an IUD in place – and in these cases the risk of miscarriage is increased.


- Permanent methods are basically forms of sterilisation and normally involve a surgical procedure for either the male or female intended to physically and permanently ensure an egg and sperm can never meet. These are a big deal as the name suggests, they’re permanent. Couples tend to choose these methods when they have had all the children that they want.

· Female sterilisation occurs under a general anaesthetic and is either by tubal occlusion, which is where the fallopian tubes are blocked meaning that eggs released from the ovaries cannot travel into the uterus. The other method of sterilisation for women is by hysterectomy – which is the removal of the uterus and is a big deal and not normally recommended for contraceptive only purposes – it’d be more likely to be recommended if there were other issues as well.

· Male sterilisation is by vasectomy which can be done under local anaesthetic, where the vas deferens (which is the tube that carries sperm from the testes) is cut so that no sperm is released in ejaculation.

- Emergency methods – are not technically contraceptives but can act as a sort of retrospective contraceptive and are generally used following unprotected sex or if a condom has broken. As the name suggests, they are not needed very often.

· The “morning after pill” (MAP) is the most common emergency contraceptive and depending on the brand can actually work up to 120 hours after unprotected sex. How the many morning after pills work depends on each brand and their hormonal makeup. Some work to delay ovulation with the idea that an egg does not get released until the sperm from the previous sexual experience has died off, thus making it hard to get pregnant. Others effect the lining of the uterus, making it a hostile environment for a fertilised egg to implant. So again, if concerned about the ethics around beginning of life it is important to be clear on how specifically the MAP you are offered actually works.

· The copper IUD which I highlighted earlier can be inserted following sex and is effective in preventing a pregnancy by blocking implantation of a fertilised egg.

- Abstinence – of course this is probably your most reliable form of contraceptive – not having sex, and is probably your contraceptive of choice in those first few weeks after giving birth, however this may not be suitable or desirable following your recovery from childbirth, especially if your partner has anything to say in the situation.

I think I’ve covered most of the more popular methods here…

If you’re eager to read more about each method of contraceptive, see the stats and understand more of the ethics surrounding contraception these are the resources I’ve used in putting together this episode:

- Fearfully and Wonderfully Made – Megan Best (this book talks about the ethics around contraceptive methods along with full explanations of how each works)

- The Royal Women’s Hospital, Victoria

- Family Planning NSW

Artwork by @_thepeachfuzz