Polyendocrine metabolic ovarian syndrome (PMOS) — formerly known as PCOS — is one of the most common hormonal conditions affecting individuals during their reproductive years, often presenting unique challenges when it comes to family building. Those diagnosed with PMOS typically have higher-than-average levels of androgens, which can lead to irregular periods, weight gain, acne, and increased body hair. These hormonal imbalances can make conception more difficult. However, at Main Line Fertility, our experienced fertility specialists are here to guide individuals and couples with PMOS on their path to growing their families.
Why PCOS is now PMOS and What That Means for Patients
In 2026, polycystic ovary syndrome (PCOS) was renamed polyendocrine metabolic ovarian syndrome (PMOS) to more accurately reflect the condition. Despite its former name, PCOS is not simply an ovarian condition and does not require the presence of ovarian cysts. Instead, it is a complex condition involving multiple hormone systems, metabolism, and reproductive health.
The new name does not represent a new condition or change your diagnosis. Rather, PMOS provides a more accurate description of a condition that has long been known to affect the body in several interconnected ways. For patients trying to conceive, fertility care will continue to focus on how PMOS affects ovulation and reproductive health while considering each person's individual symptoms and needs.
What Causes PMOS?
While the exact cause of PMOS is unknown, contributing factors include:
- Insulin resistance: The pancreas produces insulin, which enables cells to utilize sugar. If the cells become resistant to insulin, blood sugar levels can rise. In response, the body may produce more insulin to lower these blood sugar levels. However, elevated insulin levels can lead to an excess of androgens, which may result in difficulties with ovulation.
- Low-grade inflammation: White blood cells produce substances in response to infection or injury, a process known as low-grade inflammation. Individuals with PMOS experience a type of chronic low-grade inflammation that causes the ovaries to produce androgens.
- Genetics: Certain genes are associated with PMOS, and a family history of this condition may play a role.
- Excess androgen: In PMOS, the ovaries produce elevated levels of androgen, which disrupts ovulation. As a result, eggs do not develop regularly and are not released.
Symptoms of PMOS
PMOS symptoms often begin around the time of the first menstrual period, but they can also develop later in life. While symptoms vary, common issues include:
- Irregular periods: Individuals with PMOS may have few or irregular menstrual periods, which can also last many days longer than normal.
- Too much androgen: High levels of androgens, including testosterone, can lead to excess facial and body hair, as well as severe acne.
- Polycystic ovaries: People with PMOS may have larger ovaries, and follicles containing immature eggs may develop around the edge of these ovaries.
PMOS complications include infertility, gestational diabetes, miscarriage or premature birth, sleep apnea, depression and anxiety, and endometrial cancer. Additionally, obesity is common in individuals with PMOS and can worsen complications of the condition.
Diagnosing and Treating PMOS
A doctor may diagnose PMOS by asking a patient questions about their menstrual cycle and conducting a physical exam. They may also perform a pelvic exam, ultrasound, and blood tests.
PMOS can be treated using birth control pills to regularize periods, a medication called metformin to prevent diabetes, statins to control high cholesterol, and hormones to increase fertility. Fertility treatments like intrauterine insemination (IUI) and in vitro fertilization (IVF) may help patients with PMOS conceive.
