Does The Depo Shot Impact Fertility? (Episode 645)

Full Transcript: Episode 645

Lisa Hendrickson-Jack:

This is the Fertility Friday Podcast, episode number 645.

Is the Depo shot associated with a delay in the return of fertility? Well, in today’s episode, we are going to tackle just that.

I’m Lisa Hendrickson-Jack, certified fertility awareness educator with over 20 years of experience teaching women how to chart their cycles, founder of the Fertility Awareness Institute, where we train women’s health professionals to use the menstrual cycle as a vital sign, author of The Fifth Vital Sign. I have a lot to say about this topic. I’ve been immersed in this topic for many, many years. So let’s go ahead and jump right in.

Today I’m going to be diving into a recent study that was released about the Depo shot specifically. This was a review study. And interestingly, out of the 31 studies that they were considering, four of those 31 studies made up the bulk of their research.

What they were looking at was whether or not there was a difference in how long it takes ovulation to return for women using the shot, and whether that shot is intramuscular or subcutaneous. So looking at two different methods of delivery.

Now, if you’re familiar with hormonal birth control and the different types, if this has been on your radar, then you may already know that the shot is one route of hormonal birth control that is associated with the longest return of fertility. Current WHO guidelines actually suggest that women consider the time it takes on average for their fertility to return to be about a year after injection. So that is definitely something to consider.

Unsurprisingly, the researchers found that regardless of whether the shot was intramuscular or subcutaneous, the average time that it takes for ovulation to return is somewhere between six to seven months. And that does make the Depo shot on the longer end when we’re looking at different types of hormonal birth control in terms of the time it takes your body to normalize, regulate, for ovulation to start again, and of course, for fertility to return.

I have often gone on record for saying that the shot is my least favorite type of contraception because of the significant side effects associated with it. A lot of women report weight gain, and there’s a slew of different side effects that are associated. But I would say especially because you can reliably assume that out of every other type of birth control, this one is going to take your body the longest to recover.

The Depo shot is a progestin-only hormonal contraceptive that works primarily by suppressing ovulation. When the shot is given, synthetic progestins are released, and those hormones suppress the conversation that is typically happening between your ovaries, your hypothalamus, and your pituitary gland, thus shutting down that conversation and suppressing ovulation. That is the primary mode of action.

The secondary modes of action are that it prevents normal, fertile-quality cervical fluid from being produced. If you’re not approaching ovulation, you’re not producing significant estrogen. So you’re not actually producing the hormones that you would need to be producing to stimulate the cervical mucus, the flow of mucus.

In addition to that, the uterine lining is very, very thin. So the endometrial lining changes would prevent implantation if somehow magically an egg were to poke through. The main factor is suppressing ovulation, and then one of the secondary factors is the cervical mucus. So you’re not going to see any type of fertile-quality cervical mucus when you are using the Depo shot.

Unlike the pill or even the ring or the patch or other types of birth control, once you’ve had the shot, you just have to wait until it’s done. You can’t just stop taking it.

For example, if a woman started taking birth control pills and she was not liking the side effects, or if something was going on and she was kind of unsure of what’s going on, she could literally just stop taking them and come talk to her doctor and find a different formulation. Similarly with the patch, you could take it off, or the ring, you could remove it. But obviously with the Depo shot, you are committed and you just have to wait until it comes out of your system.

If I take a direct quote from the paper, the researchers say, quote, “Users should be informed that there can be a delay of up to one year in the return to ovulation after discontinuation,” end quote.

One of the points that the researchers made in the paper, which I do think is just important to consider, is when they were looking at the average time that it takes users to resume ovulation. Depending on the formulation, it was an average of six to seven months.

Now, if you think about what an average is, an average means that some women started ovulating earlier, and obviously some women started ovulating much later. When we look at the absolute maximums, there were some women that were not ovulating again even until the year mark had passed. But the average was about six to seven months. So that’s something to keep in mind.

But even though ovulation is resuming at this time, that doesn’t necessarily mean that that would be equal to the time to pregnancy. It is worth noting that time to pregnancy post Depo shot is not what they were measuring. And so just because a woman may start ovulating an average of six to seven months after they’ve stopped doesn’t mean that that’s when they’re going to get pregnant.

And actually, when we look at time to pregnancy studies, depending on how long the users were using Depo-Provera or any other similar type of shot, the average time to pregnancy ranged anywhere from 12 to 15 months, in some cases even 18 months. And this is something that I’ve spoken about and written about previously in my first book, The Fifth Vital Sign.

Ultimately, what does this mean? What do we do with this information? My position and stance on hormonal contraceptives has always been that I am thankful that we have all these different options. I do think it is wonderful that we have options. But in order for them to really be true options, we need to have the awareness and the knowledge about all of the potential upsides and downsides when we are considering hormonal contraceptives.

If you’re a women’s health practitioner and you are counseling your clients as to what types of options they may have, I think it is really important to be able to intelligently discuss the differences between combined oral contraceptives, progestin-only oral contraceptives, the ring, the patch, to be able to recognize what the difference is, not just in delivery route, but in side effect profiles, and also in the return of fertility, potentially the return of ovulation.

When it comes to the shot, it is important to recognize that it is associated with the longest return to ovulation, and therefore also the longest return of fertility. So if you have a client and they have a shorter horizon to conception, then that should be something that’s taken into consideration before they even consider something like the Depo shot.

As with most contraceptives, there’s no evidence that these issues are permanent, but there is this temporary period of transition. And I would say it’s most pronounced in women who are coming off the Depo shot.

This is certainly one of the benefits, whether you are a women’s health practitioner and you are supporting clients who are coming off contraceptives, or whether you yourself are coming off contraceptives and you’re trying to figure it all out. This is certainly one of the benefits of cycle tracking and starting to understand what’s happening in your cycle: being able to track your period, your fertile window, your cervical mucus changes, your luteal phase length, which would be the duration of time between ovulation and your next period.

Being able to track these signs helps you to really understand what’s going on. It helps you to understand, am I even ovulating? Is ovulation happening? And is it happening normally? These are things that we can start to get a deeper insight into when we start tracking our cycle.

To conclude, as I’ve already mentioned, unsurprisingly, the shot is certainly not my favorite option when it comes to hormonal contraceptives. There’s a whole conversation to be had on how I feel about the other ones, but today’s topic was on the shot specifically.

And the bottom line is that it’s so important for us to be informed about all of the different aspects of these contraceptives before we are even considering going on them, or recommending them to clients, or even having an intelligent conversation as a women’s health practitioner with your clients.

With that said, I hope you have a wonderful week, weekend, whenever you are tuning into the show. And of course, as always, until next time, be well and happy charting.