Is it OK to miss one day of progesterone?

No, if you miss one day of progesterone, especially if you have had an IVF or an IUI is never an issue because your ovaries are going to produce your own progesterone. In other cases, for example, if you’re having a cryotransfer, and you are under a hormone replacement treatment or if you are going through an egg donation, and you are also on hormonal replacement therapy, I would say it’s not an issue. The reason is that the progesterone can keep the levels for some time, and I’ve got cases in which patients thought that they had a miscarriage, they have stopped the treatment even for five or six days, and when they have come, and we have done the scan there was an embryo with a heartbeat they are resuming the treatment and nothing abnormal has happened. Probably, if you just missed one day, there’s not going to be a problem, and the pregnancy is going to go perfectly.

There are cases in which patients also ask that when they are not sure if they are taking the progesterone or sometimes, they have a really important leakage of progesterone, and they are not sure if the pessary has remained inside the vagina or not. They ask us if they can take another progesterone pessary. The only thing I can say is that in regard to progesterone, it’s better to have more than less of it. Whenever you have any doubt that the pessary has been properly placed inside a vagina, or you may have lost a lot of progesterone, take another one, and that’s it, it’s a completely safe procedure.

Well, I think actually, there is no fatal thing that will happen if a person misses one day of progesterone. We know there are examples where our patients forgot to take their progesterone and the pregnancy still occurred. But of course, this is the risk of failed attempts so it is better to write down in your diary that you need to take progesterone three times a day or one time a day, depending on the dosages. It is better to not miss the progesterone.

Forgetting to take your progesterone is not good because progesterone is what we call “the hormone of the pregnancy”. It will prepare the endometrium for the implantation of the embryo so if you forget your progesterone, we can say that theoretically chances of getting pregnancy could be lower but things should be discussed with your practitioner. It depends how many pills have you forgotten and in some scenarios, we should cancel the cycle and then restart for an embryo transfer.

It’s always recommended that you take medicines as it’s prescribed and we think that progesterone taking it daily, gives you the right levels and that’s what all the studies have been based on to check progesterone levels are fine. If you miss one or two – is it likely of to cause a problem – probably not and certainly if it was unsuccessful, I wouldn’t go back and say oh it’s because I forgot to take that progesterone tablet and I’d really try and reassure you because it’s likely there’s another reason why it’s not worked. Having said that it’s really important to try and remember to take it. There’s so many things now you can use with technology: there’s apps, you can use to set a reminder in your phone to take it a certain time each day – there’s lots of different things you can use to try and remind yourself to take medications and it’s worthwhile thinking about some of those strategies or getting it into your routine whilst you’re going through treatment.

If you undergo an IFV cycle with the fresh embryo transfer or you do a frozen embryo transfer in a natural cycle, your ovaries will produce progesterone. However, we always administer some progesterone. So, in these cases, if you miss one day of progesterone, probably nothing happens. If you do an embryo transfer in an artificial cycle, your ovaries do not produce progesterone, so in these cases, of course, I don’t recommend missing one day of progesterone because it could cause hormonal imbalance and even bleeding especially in the first moments, the beginning of pregnancy.