Polyendocrine Metabolic Ovarian Syndrome (PMOS) is a hormonal and metabolic condition that commonly affects ovulation. Women with PMOS often have higher number of small follicles, which may suggest a good ovarian response during IVF treatment, says Dr Aashita Jain, Fertility Specialist, Birla Fertility & IVF, Surat. Although a higher follicle count may indicate the potential to retrieve more eggs during IVF, it does not necessarily translate into more mature eggs, more embryos, or a higher chance of pregnancy. This is because ovarian response and embryo development depend on different biological factors.
How does PMOS affect egg development?
In women with PMOS, hormonal imbalances can interfere with normal egg maturation. Elevated levels of Androgens, commonly called male hormones, and insulin resistance may affect the environment in which eggs develop. As a result, some eggs retrieved during IVF may be immature or may not develop as expected after fertilisation. Not every follicle yields an egg, and not every retrieved egg will be mature enough for fertilisation. Egg maturity and egg quality are distinct factors; an immature egg is not necessarily genetically abnormal.
However, these effects vary considerably between women. Having PMOS does not necessarily mean that egg quality is poor, and many women with the condition achieve successful pregnancies.
Why do some embryos stop developing?
Embryo development depends on several factors, including egg-related factors, chromosomal health, sperm quality, successful fertilisation and laboratory conditions. Maternal age is also important because the likelihood of chromosomal abnormalities in eggs increases with age. Therefore, poor embryo development cannot automatically be attributed to PMOS alone.
Why does ovarian stimulation require special attention?
Women with PMOS may respond strongly to fertility medications because their ovaries contain many small follicles. This increases the risk of Ovarian Hyperstimulation Syndrome (OHSS), a complication in which the ovaries become enlarged and fluid may accumulate in the abdomen.
Doctors therefore carefully select medication doses and monitor follicular growth through ultrasound examinations and, when appropriate, blood tests. In women at higher risk, specific stimulation protocols and freezing embryos for later transfer may help reduce complications. For women at increased risk of OHSS, an appropriate stimulation protocol, a suitable trigger medication and freezing embryos for transfer in a subsequent cycle may help reduce the risk of complications.
What should a fertility assessment look at?
When embryo development is repeatedly poor, the specialist needs to review the entire cycle rather than focus only on the number of follicles or eggs retrieved. This may include the eggs’ maturity, fertilisation results, embryo development patterns, sperm parameters and the stimulation protocol used. The assessment may also include the stage at which embryo development stops, relevant sperm-related factors, maternal age and laboratory conditions.
The treatment plan can then be adjusted according to the findings. There is no single protocol that suits every woman with PMOS, and repeated poor embryo development should prompt a closer review rather than an assumption that the condition alone is responsible.
For couples undergoing IVF, follicle numbers provide useful information about ovarian response, but they cannot independently predict embryo development or the outcome of an IVF cycle. The goal is to achieve an appropriate ovarian response, obtain suitable mature eggs, support embryo development and maximise the possibility of a healthy pregnancy while prioritising patient safety.
