Many women leave the scan room with one sentence echoing in their head: “Your ovaries look polycystic.” It sounds like a verdict, when in fact it is only one of three features a doctor weighs before confirming PCOS. This article explains what is actually being looked for on the ultrasound screen, the numbers a doctor counts, and why many unmarried women in Malaysia never need a transvaginal scan at all.

What the doctor looks for on screen

During an ovarian ultrasound, the doctor is not hunting for “cysts” in the everyday sense. What they look at are follicles, the small fluid-filled sacs measuring 2 to 9 millimetres, each carrying an immature egg. On a polycystic ovary these follicles are numerous and arranged around the rim, sometimes described as a “string of pearls” appearance.

Two things are measured and recorded:

  • Follicle number per ovary (FNPO). The doctor counts how many 2 to 9 mm follicles sit in each ovary.
  • Ovarian volume. An ovary enlarged beyond a set threshold also counts as a marker.

It helps to understand that polycystic ovarian morphology (PCOM) on the screen is not a disease in itself. It is a structural sign. The actual diagnosis depends on combining this picture with symptoms and blood tests, not on a single image. To see how the three features fit together, read the PCOS diagnostic criteria.

The numbers: 20 follicles or a volume of 10 mL

This is the part that changes most often and is most often misunderstood. The 2023 international PCOS guideline (Monash, ESHRE, ASRM), which also guides practice in Malaysia, sets the thresholds as follows:

  • 20 or more follicles in at least one ovary, when the ultrasound machine uses a high-frequency transducer (8 MHz and above). Most modern machines meet this.
  • If the machine is older or the image is not clear enough for a reliable follicle count, doctors rely more on an ovarian volume of 10 mL or more as the main marker.
  • When image quality does not allow a reliable follicle count, an ovarian volume of 10 mL or more in one ovary can be used as the marker instead.

That number 20 is higher than the old threshold. The original 2003 Rotterdam criteria used 12 follicles, but ultrasound machines of that era were less detailed. As resolution improved, more small follicles became visible even in healthy women, so experts raised the bar to avoid mislabelling normal women. If an older scan report mentions 12 to 19 follicles, that may no longer count as polycystic under current standards, which is worth revisiting with your doctor.

Transvaginal or transabdominal: which is for you

The transvaginal scan (TVS) uses a probe inserted into the vagina, and it gives the clearest view of the ovaries because the probe sits closest to them. For that reason it is considered the preferred method in terms of technical accuracy.

In Malaysia, however, cultural and religious context is taken seriously. In the case of women who are unmarried or have never had intercourse, the transabdominal scan (through the abdominal wall) is the default first-line method, not the transvaginal one. You do not need to feel pressured or fear being forced into a transvaginal scan. PCOS can still be confirmed without one. When the abdominal scan cannot give a clear follicle count, the doctor usually relies on ovarian volume as the marker, or combines it with symptoms and blood tests.

For a clearer abdominal scan, clinics often ask you to hold your urine so that a full bladder pushes the bowel aside and makes the ovaries easier to see. Arriving with a full bladder can save time and avoid a repeat scan.

When ultrasound is deliberately not used

There is one important situation where ultrasound is intentionally left out of the diagnosis: in adolescent girls within the first eight years after their first period (menarche). The reason is that healthy young ovaries naturally carry many follicles, so a “polycystic” appearance at a young age is very common and means little. Under the 2023 guideline, PCOS in adolescents is diagnosed on the combination of irregular periods and signs of high androgens alone, without ultrasound or AMH testing. This protects teenagers from an inaccurate PCOS label. This topic is covered further in the adolescent PCOS guide within the same silo.

Likewise, if you already have two other clear features, namely irregular periods and confirmed excess androgens, the doctor may confirm PCOS without needing an ultrasound at all. The scan is most useful when the picture is still unclear and a third feature is needed to complete the diagnosis.

A scan does not tell the whole story

Two things are worth remembering after you leave the scan room. First, many perfectly healthy women have ovaries that look polycystic with no problem at all, so the image alone is not a diagnosis. Second, some women who genuinely have PCOS have ovaries that look normal on the screen, especially with certain PCOS types. That means a “normal” scan does not rule out PCOS if symptoms and blood tests point the other way.

This is why an ultrasound is never read in isolation. The doctor reads the scan alongside your menstrual pattern, physical signs such as acne or excess hair, and hormone blood tests. If you have just been diagnosed and feel lost in the terminology, the guide on first steps after a PCOS diagnosis lays out what to do one step at a time.

Cost and next steps in Malaysia

At a KKM Klinik Kesihatan, a basic visit costs only RM1 for Malaysian citizens, with referral to a government hospital O&G clinic for ultrasound following the usual pathway: Klinik Kesihatan, medical officer, then hospital referral. Specialist follow-up is usually around RM5. At private clinics and hospitals the cost varies by centre, so it is wise to ask about the price before booking.

If you are thinking of using supplements while waiting for an appointment, remember that no supplement directly changes the ovarian picture, and the evidence for most is still moderate to limited. Talk to your doctor first, and check halal status and NPRA registration. Basic information on these options is in the PCOS supplements guide.

When to see a doctor: if your period has been absent for more than three months, if you notice sudden and severe hair growth, or if you are worried about fertility, do not wait. PCOS also raises the long-term risk of type 2 diabetes and heart disease, so an early confirmation helps you plan monitoring, not just satisfy curiosity.