Progestogen-Only Contraception - Pill, Implant and Injection - Essential GP Revision

Progestogen-only contraception for general practice exams.

Video version: https://youtu.be/0DFUqIzhsWw

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Transcript

SPEAKER_01 0:00

Hi, this is Tom and welcome to the Zero to GP podcast. In this episode, we're going to be going through progestogen only contraception, all the key stuff you need to know for your GP exams. And as always, the format of these episodes is I'm going to present you with cases and ask you questions. I want you to come up with your answer in the pause. Ideally say it out loud or write it down so you really know whether you know that information or not. And then I'll go through an explanation. So let's jump straight in. The first case is a 34-year-old woman, and she comes into a GP because she wants contraception. She's otherwise well, but she does have a family history of a deep vein thrombosis which affected her mother. The first question is, what would be the UK MEC, which is the UK medical eligibility criteria for contraception, for the combined oral contraceptive pill? The UK MEC for the combined pill, if there's a first degree relative with a history of venous thromboembolism, like we have in this case, is three. So the risks would outweigh the benefits in this patient for the combined pill, so it wouldn't be recommended.

SPEAKER_00 1:27

My next question is: what would be the UK MEC for the progestogen-only pill?

SPEAKER_01 1:42

The UK MEC for the progestogen-only pill with a family history of deep vein thrombosis is one. So the progestogen-only pill is not known to increase the risk of venous thromboembolism, so DBTs and PEs. However, the combined pill does increase the risk. So in this case, the progestogen-only pill would be fine, but the combined pill would be too risky. So it should be more suitable for progestogen-only contraception.

SPEAKER_00 2:10

My next question is what are the progestogen-only contraceptive options?

SPEAKER_01 2:31

There are four types of contraception that contain only progestogens. They are the pill, for example, desigesteril, the injection, which you have every twelve to thirteen weeks, which contains just progestogen, the implant, which gets inserted, it's like a little matchstick inserted in the upper arm typically, and that releases progestogen. And finally the levonogesteral intrauterine device. So this is a coil, for example, the marina coil, and that releases progestogens just locally inside the uterus. My next question is what is the mechanism of action of progestogen-only contraceptives?

SPEAKER_00 3:18

How do they work to prevent pregnancy? So they have three main mechanisms of action.

SPEAKER_01 3:39

The first is that they inhibit ovulation. Not all of them inhibit ovulation. For example, the progestogen-only pill doesn't typically inhibit ovulation, although with desigesterol, a lot of women do stop ovulating. But that's not the main mechanism for the progestogen-only pill. And with the intrauterine system, so the marina coil or other progestogen-only coils, they don't always inhibit ovulation. They do in a small number of women, but that's not their main mechanism of action. But for the implant and injection, they do inhibit ovulation. The second mechanism of action is that the progestogens thicken the cervical mucus. So there's a mucous plug in the cervix that prevents sperm from getting past the cervix into the uterus and then the fallopian tubes where they cause um where they cause conception. So if the sperm can't get through the cervix, pregnancy can't occur. And then the third mechanism of action is that they thin the endometrium, which makes it less um accepting of implantation and less likely to develop into a pregnancy. Okay, on to so we've got this 34-year-old woman, and she wants to start the progestogen-only pill. My question for you is when do you start the progestrogen-only pill? When should this woman take away the pill box and start taking it? So she can actually start it any time of her menstrual cycle. But there's some key things. If she starts on day one to five of the menstrual cycle, day one being the day that she starts bleeding, if it's day one to five, she's immediately protected from pregnancy. So that's a great time to start it because she doesn't need to think about anything else. However, if she starts after day five, firstly, she needs to be sure she's not already pregnant. So she hasn't had any unprotected sexual intercourse since her last period. That's one way. Uh, but there are other ways to tell that she's not pregnant. For example, she's had a pregnant, let's say she's not uh having periods, she's had a pregnancy test at least 21 days since her last unprotected sexual intercourse. However, we're overcomplicating things, we'll get onto that. But if she's after day five, she'll need extra protection for the first 48 hours of taking the pill. So with a progesterogen-only pill, it takes 48 hours for that cervical mucus to thicken enough that she's protected from pregnancy. So if she starts in the day one to five, she's immediately protected. After day five, she needs to use extra protection, for example, condoms, or avoid sexual intercourse for at least 48 hours of taking the pill. Hope that makes sense. Okay, on to the next question, which is what follow-up would you arrange in general practice as a GP after initiating the progestogen only pill for the first time? The guidelines recommend following up at 10 to 12 weeks. And this is to check everything's going okay with the pill, no adverse effects, managing to take it uh on time and all that kind of stuff. Okay, on to the next case, which is a 28-year-old woman and she's two weeks postpartum. She gave birth two weeks ago. She wants contraception.

SPEAKER_00 7:34

First question is can you start the progestrogen only pill at this point? So she's two weeks postpartum.

SPEAKER_01 7:50

You can start the progestogen-only pill at any time after a woman gives birth. She's immediately protected from pregnancy if she starts the progestogen-only pill within 21 days of giving birth. So they say you can't get pregnant 21 days after giving birth, you won't ovulate. So if you start the progestogen-only pill during that time, uh she's immediately protected. This is in contrast to the combined pill, which you can't start until three or six weeks after giving birth, depending on whether you're breastfeeding or not, because of the risk of venous thromboembolism. Okay, on to the next case is a 46-year-old woman, and she's had no periods for the past four months.

SPEAKER_00 8:40

The next question is how are you going to exclude pregnancy in this patient?

SPEAKER_01 8:56

So she's 46 and no periods for the past four months. She may be perimenopausal, which is why there's a large gap between her periods, but she could potentially still get pregnant at this age. The key way to exclude pregnancy is that she's had no unprotected sexual intercourse in the past 21 days, and she has a negative urine pregnancy test. If you have uh unprotected sex and then you do a pregnancy test within 21 days of that unprotected sex, there could be an early pregnancy that's not yet producing enough HCG to make a pregnancy test positive. So it needs to be 21 days after the last unprotected sexual intercourse to exclude a pregnancy. Okay, on to the next case. The next case is an 18-year-old woman. She takes the combined oral contraceptive pill, and now she's switching to desigesteral from the combined pill. Maybe she's come in with new headaches or migraines and it's decided on a risk-benefit analysis that is better on the progesterone only pill. So she's switching to desigesterol. My question is when can she start the desigester pill immediately? When would it be fine to switch straight from the combined pill to the desigesteral pill?

SPEAKER_00 10:37

So there's two scenarios where she could switch directly.

SPEAKER_01 10:40

The first is if she's in week two or three of the combined pill, meaning that she had the hormone-free interval, she's had the full first week of the pill pack, the full seven days, and now she's in week two or three. At that point, she could stop the pill and the next day start the desigesteral pill and she'll be immediately protected. The other scenario is if she's in day one or two of the hormone-free interval. So she's finished the pill pack and now she's on day one or two of the hormone-free interval. At that point, she could just immediately start taking desigesterol and she'd be protected. Let's say a different scenario, she's currently on day three of the hormone-free interval. And she tells you she's had no unprotected sexual intercourse since the start of the hormone-free interval.

SPEAKER_00 11:34

In this scenario, how are you going to switch her to the combined pill?

SPEAKER_01 11:49

So the recommendation here, if you can do, is if someone's on day three plus of the hormone-free interval, then they'll need additional protection for the first 48 hours. So they can start the desigesterol pill straight away, but they'll need additional protection for the first 48 hours. Now the caveat here is that they need to have had no unprotected sexual intercourse since the start of the hormone free interval. So let's say she's currently on day three of the hormone free interval, and she had unprotected sexual intercourse yesterday.

SPEAKER_00 12:27

In this scenario, how are you going to switch her to the digesteral pill?

SPEAKER_01 12:45

So in this scenario, she's not necessarily protected from um from pregnancy here because she's had unprotected sex and she's on day three of the hormone-free interval. So the way to switch here is to restart the combined contraceptive pill and then take it uh consistently for seven days and then switch to the desigesteral pill. So she's past day one and two. If she was on day one and two of the hormone for interval, she could switch immediately, start desigesteral, and she's protected. But because she's day three or above and she's had unprotected sex, then she needs to restart the combined pill and take that for seven days. And this is to suppress ovulation. And then after she's been taking it consistently for seven days, then she can switch to desigesterol. In some scenarios, it may not be appropriate to restart the combined pill. For example, they've developed migraines with aura. And that's in this scenario, you um you can quick start desigesterol, but you'd need to consider emergency contraception and a urine pregnancy test at least 21 days after the episode of unprotected sexual intercourse. And of course, she would need uh additional protection for 48 hours after starting desigesterol. Okay, onto a new scenario. We've got a 25-year-old woman and she wants long-acting contraception. She doesn't want to be taking the pill every day. My question to you is how long acting is each option? So you're gonna have to give the long-acting options of reversible uh contraception, and how long those uh are valid for once you once you have them. Okay, so there's four long-acting reversible contraception options. So let's go through each one of those. The first is the injection, for example, Depo Provera. And this injection lasts for 13 weeks in terms of protecting against pregnancy. So they say you need a new injection every 12 to 13 weeks. It is kind of um potentially lasts for 14 weeks, but officially 13 weeks, and they recommend a new injection every 12 to 13 weeks. The second is the implant, for example, Nexplanon, which is that little matchstick that goes in the upper arm. And this lasts for five years. The next one is the levinogesteral intrauterine device, for example, the marina coil. And these devices, there's quite a few of them, I believe there's five currently in the UK market, and they last a varying amount of time from three years up until eight years. So the marina coil, once it's put in place, it protects against pregnancy for eight years. And the final one is the copper coil. Depending on the device, this will last from five to ten years. So the longest potential one is a copper coil that lasts for ten years. The next question is which one of these long-acting contraceptives can cause weight gain? The only one officially known to cause weight gain is the injection, for example, Depo Provera. My next question is which which of which two of these long-acting reversible contraceptives require caution in a patient who's younger, for example, younger than eighteen. So the coils, meaning the levin or gestral, intuitively device or the copper coil, are UKMEC2 in patients under 20. And the reason they require caution for coils in patients under 20 is there's a higher risk of expulsion. So a higher risk that the coil will pop out and then it won't be effective and won't protect against pregnancy. The injection, the DMPA injection, uh is UKMEC2 in patients under 18. And the reason for this is that it has the potential to reduce bone mineral density in patients under 18 where their skeleton is still growing and hardening. Um, if you give them the injection, there's a risk that it will thin the bones, and um the sort of anti-estrogen effect will mean that the bones are not as strong. My next question is when are you going to start these long-acting progestogen-only contraceptives? So here we're talking about long-acting progestion-only contraceptives, meaning the implant, the injection, or the myrena coil, the hormone coil. If you give them uh or insert them on day one to five of the menstrual cycle, then uh they're immediately protected. If it's after day five, they need to use additional protection for the first seven days. So unlike the progestogen-only pill, which requires additional contraception for two days, the long-acting ones require additional protection for seven days. Okay, onto a new case. A 23-year-old woman who started the progestogen-only pill 10 weeks ago. And she's come in because she has unscheduled bleeding. She says, I'm I'm having bleeding like a period, but it's kind of erratic and I can't predict it, and it's not so not so good.

SPEAKER_00 19:24

My first question is which key tests are you gonna consider in this patient? So two key tests.

SPEAKER_01 19:41

The first is a sexually transmitted infection test, so you can do a urine sample or swab, particularly testing for chlamydia, but you can test for others like Connery as well. And the second one is a pregnancy test to exclude pregnancy. My next question is are you gonna perform a speculum or pelvic exam in this 23-year-old who started the POP 10 weeks ago and is having unscheduled bleeding? Now this depends if uh the bleeding is quite obviously or very likely due to the pill and is kind of typical unscheduled bleeding associated with progestogen only contraceptives. You don't need to or you you aren't recommended to perform a speculum or pelvic exam until the bleeding has persisted for more than three months. It's not necessary to perform the examination. However, you would consider performing an examination if the woman has not had cervical screening, because you want to have a look at the cervix and make sure there's no cervical pathology, for example, cervical cancer. Um, if the woman requests an examination, then you would um you know perform that for her. Or if there's other symptoms that will make you suspicious about other pathology, for example, pain or postcoital bleeding. In these scenarios, it's worth performing examination. But if it's typical progestrogen-only contraception-induced uh irregular, unscheduled bleeding, they don't need to necessarily need an examination until the bleeding's persisted more than three months. You can assume it's because of the contraception. Okay, on to the next case. You've got a 19 year old woman. She's had the implant, the progesterone only implant, for six months. And she's been having unscheduled bleeding during that time. You've examined her and performed some testing, for example, estimating. Testing and these are all normal. So you're not concerned about any kind of pathology other than it's the implant causing this bleeding. What options do you have to manage this bleeding? She doesn't want to have the implant taken out if she can avoid it, so what can you do instead to manage the bleeding?

SPEAKER_00 22:35

There's two options here.

SPEAKER_01 22:37

The first is you could give her methanamic acid, which is an NSAID that helps reduce the bleeding and shorten the bleeding time, which she could take when the bleeding occurs for up to five days. So she starts having an unscheduled bleed, takes methanamic acid, and it will shorten the bleed. The second option is to give her the combined oral contraceptive pill on top of her implant, and you can use that for up to three months to kind of get control of the bleeding and then hope that the bleeding then stays settled after that's stopped. Okay, and on to the final case, which is a 21-year-old woman. She takes the progestogen-only pill and she comes in because she's missed a pill. My question to you is when is the progestogen-only pill classed as a missed pill? At what point would you say she's missed the pill?

SPEAKER_00 23:47

This depends on the type of pill that she's taking.

SPEAKER_01 23:51

For the traditional progesterogen-only pill, for example, levanogesterol pill, uh it's after three hours. So if she's three hours or more late of taking the pill, she's missed that pill. For the desigesteral progesterone-only pill, it's more than 12 hours after the scheduled pill time. And for the Drosperinone progesterone-only pill, it's more than 24 hours after the missed pill. My next question is what's the missed pill advice you're gonna give this patient taking the progesterone-only pill? So she needs to take the missed pill as soon as she remembers, and then continue with the other pills in the pack at the normal time. So this might mean taking two pills in the same day. She'd also need extra protection, so avoiding intercourse or uh take using condoms, additional protection for 48 hours until she's been taking the pill regularly again. So the 48 hours until she's established back on the pill. And if she's had unprotected sexual intercourse, you need to consider emergency contraception. So if she's had unprotected sex since the missed pill, uh she could be um the the cervical mucus could have thinned enough that it's allowed the sperm through, and she could uh be susceptible to pregnancy. So emergency contraception should be considered. Final case or final question is a 21-year-old woman and she comes in with a positive pregnancy test, and she's been taking the progestogen only pill. Maybe she's missed a few and she's not been taking it perfectly, she's become pregnant, and she says she wishes to continue with the pregnancy.

SPEAKER_00 25:58

What advice would you give this patient? So she's a pregnant woman who's been taking the progesterone-only pill.

SPEAKER_01 26:16

She should stop the progestogen-ony pill. And um it's worth noting to her that the progester-ony pill is not known to be harmful to pregnancies. So women who got pregnant while taking the progestogen-only pill, it's not known to harm the pregnancy or cause any issues with the baby. She'd also need other pregnancy advice, for example, make sure she's taking folic acid, vitamin D, books in with the midwife, and so on. So, thanks for listening to this episode on the progestogen-only contraception. Hopefully, it was helpful. A few resources for you if you're preparing for GP exams. The first is the AKT revision book. This book covers all the key topics you need for your GP exams. There's also the zero to GP.com website where I go through uh or where you'll you can find questions, flashcards, a fact trainer tool, and notes for your GP exams. And I've got an upcoming revision course in September in London where we go through the whole GP curriculum for the AKT exam. So check out those resources. Subscribe if you're not already subscribed to the podcast or the YouTube channel, and I'll see you in the next episode.