Stimulation PPOS (Progestin- Primed Ovarian Stimulation)

Progestin-Primed Ovarian Stimulation (PPOS) is a newer IVF stimulation protocol used to help prevent premature ovulation during an IVF or egg freezing cycle.

Traditionally, IVF stimulation requires daily hormone injections alongside additional medications. With PPOS, an oral progesterone medication is used instead to suppress ovulation during stimulation. 

PPOS has become increasingly popular in fertility treatment, particularly for:

• Egg freezing

• Fertility preservation

• Patients planning genetic testing (PGT)

• Some patients with low ovarian reserve or at risk of OHSS 

One of the main advantages of PPOS is that it may reduce the number of injections required during treatment, while still achieving similar pregnancy outcomes compared with conventional IVF stimulation protocols. 

Current research suggests PPOS can provide:

• Similar pregnancy and live birth rates

• Good control of premature LH surges

• Lower rates of ovarian hyperstimulation syndrome (OHSS) in some patients 

Because progesterone can affect the uterine lining during the stimulation cycle, embryos are frozen and transferred in a later cycle rather than as a fresh transfer. 

PPOS is usually a good option for patients with a normal ovarian function who aren’t planning to have an embryo transfer in the same cycle. This might include people having preimplantation genetic testing, or those choosing to freeze their eggs or embryos for future use.

Your Care Fertility specialist can talk you through whether PPOS is the right option for you and your individual treatment plan.