

Contraceptive medications act in two ways in the reproductive system: at the ovarian level they block ovulation, and at the uterine level they thin/atrophy the endometrium so that, if a hypothetical embryo were present, it would not implant.
Moreover, the effect of contraceptives on fertility is temporary—their inhibitory effect exists only while they are being taken, and no longer. Using contraceptives before a fertility treatment may seem contradictory, but in reality it is part of a strategy to optimize treatment outcomes.
The use of contraceptives in fertility treatments
Although these medications are normally used to prevent unintended pregnancy, one of their secondary functions is the ability to regulate cycles in women with irregular periods or in patients with prolonged amenorrhea.
This means contraceptive drugs can also be used in assisted reproduction treatments. They are not used in 100% of cycles, but they are appropriate for women who have irregular cycles or who require more precise scheduling to carry out the treatment (start date of menstruation, date of oocyte retrieval, or date of embryo transfer).
How long are contraceptives taken before treatments such as IVF?
When the patient’s period begins, an ultrasound is performed to confirm the status of the uterus and ovaries. At that point, the contraceptive is started on the first, second, or even third day of bleeding. They are usually taken for about 12–14 days, though in some cases a longer duration is necessary.
Here, the goal of the contraceptive is to suppress the ovary’s natural function, which is confirmed by ultrasound and/or hormone testing, so that it can be kept “at rest” and the treatment can begin at any planned time.
After the required days, the contraceptive is stopped, and after a washout period of approximately 5 days, controlled ovarian stimulation with subcutaneous gonadotropins is initiated. A control ultrasound may be performed for this, although it is not absolutely necessary.
In conclusion:
- Not all treatments require contraceptives.
- There is no scientific evidence that the use of contraceptives reduces the success of reproductive treatment.
The decision to use contraceptives as part of fertility-treatment preparation depends on each patient’s medical evaluation and specific clinical circumstances.
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At Fertility Madrid, we specialise in treatments such as egg donation, in vitro fertilisation and artificial insemination, among others.
Please do not hesitate to contact our professionals at our fertility clinic and they will answer all your questions without obligation.