Known as the pregnancy hormone, progesterone is essential for the successful implantation of a fertilized egg and so plays a key role during fertility treatment. We take a look at this hardworking hormone to ask: what’s the link between progesterone and IVF?
What is progesterone?
Progesterone is a hormone that is naturally produced by the ovaries and plays an essential role in ensuring that the female body is ready for pregnancy by creating a supportive environment for the embryo. It does this by thickening the lining of the uterus for a fertilized egg’s implantation.
A woman’s body will normally produce progesterone around the mid-point of their menstrual cycle, which is when she ovulates, and an egg is released. Once fertilized, the egg ‘sticks’ to the ready and waiting uterus lining, resulting in a pregnancy. However, should the egg remain unfertilized or fail to implant, progesterone levels will drop, resulting in a woman’s period.
In the case of a successful pregnancy, the ovarian follicles will continue to produce progesterone until around 8-10 weeks, when the placenta takes over the hormone’s production through to birth. Placenta-produced progesterone works to support the pregnancy to term by preventing the uterus lining from shedding as well as suppressing the uterine wall’s ability to contract until the full term of the pregnancy.
Reasons it is used during fertility treatment
The medications used during IVF to prevent premature ovulation can, unfortunately, affect and even suppress a patient’s ability to naturally produce the required amounts of progesterone needed to thicken the uterus lining. And the procedure of follicle aspiration to collect mature eggs can also, at the same time, remove many of the progesterone-producing ovarian cells, reducing the body’s ability to produce enough of the hormone naturally.
Which is why the best fertility clinic specialists will look to prescribe a progesterone supplement to bring everything back into balance, so the fertilized embryo has the best opportunity to successfully implant and complete a full pregnancy.
How progesterone is used during IVF
If prescribed by your fertility specialist, progesterone supplementation will start a couple of days after the initial egg collection procedure and before the embryo implantation. Once a pregnancy has been confirmed, the progesterone treatment can continue for 10-12 weeks, or the duration of the pregnancy’s first trimester.
After this time, the treatment can be safely withdrawn as the woman’s body regains its natural ability to produce the progesterone hormone for the rest of the pregnancy.
Types of progesterone supplementation
Progesterone during IVF treatment will usually come in two forms, intramuscular injection or a vaginal preparation. Vaginal treatments are available as a suppository, gel or vaginal tablet, which need to be taken/applied daily.
There is no real difference between the two methods and the final choice is down to personal preference as well as your IVF clinician’s advice.
Potential side effects of progesterone treatment
If you opt for an injection, you may experience some localized pain or swelling near the injection site, while vaginal preparations can cause discharge or irritation. Other non-serious potential side effects including bloating, nausea, cramping and fatigue.
And with progesterone treatment during IVF, the hormone supplement can be safely withdrawn once a positive pregnancy has been confirmed. But as with any treatment, you are advised to report any concerns or unusual symptoms to your doctor or fertility clinician.
