When you are trying for a baby, you start noticing things you may not have paid attention to before. You count the days after your period, watch for changes in your body and try to recognise when you are ovulating. Sometimes this gives you confidence. Other times, it raises more questions. You do not have to work it all out on your own. With folliculometry, your doctor can track how your follicles develop throughout your cycle, help you identify when you are most likely to conceive and assess whether you need further investigation.
What is folliculometry and what can it show?
A follicle is a small, fluid-filled structure in the ovary where an egg develops. In a natural cycle, one of the growing follicles usually becomes dominant. At ovulation, it ruptures and releases the egg.
During monitoring, your doctor measures the follicles and assesses the thickness and appearance of the uterine lining, known as the endometrium. A follow-up scan allows the doctor to compare the findings. A decrease in the size or disappearance of the monitored follicle, the formation of a corpus luteum and, sometimes, free fluid behind the uterus can all help indicate that ovulation has occurred.
An ultrasound scan shows the follicle. It cannot determine the quality of the egg inside it. Even when the follicle has reached a size consistent with approaching ovulation, its size alone cannot tell you whether fertilisation or pregnancy will occur.
When might your doctor recommend ovulation monitoring?
Monitoring can be useful if you have irregular periods, if your doctor suspects you are not ovulating or if you are having difficulty conceiving and more information is needed. It can also be used in preparation for insemination or as part of treatment to induce ovulation.
If you are taking medication to stimulate your ovaries, the doctor also checks how many follicles are growing. This helps assess your response to treatment and the risks, including the risk of a multiple pregnancy. If the ovaries respond too strongly, the plan for that cycle may need to change.
Some women will not need a series of ultrasound scans when they start trying for a baby. Regular cycles are often a sufficient indication that ovulation is occurring. A consultation can help determine whether monitoring would answer a specific question in your case.
What happens during folliculometry?
The scan is usually transvaginal. Your doctor gently inserts a slim ultrasound probe covered with a protective sheath and gel into the vagina. You may feel pressure or mild discomfort. If you are in pain or feel anxious, tell your doctor at the start. You can ask to pause at any time.
You usually need an empty bladder for a transvaginal ultrasound. Follow the instructions you receive when you book, especially if you are also having an abdominal scan. The procedure uses no ionising radiation, and you can usually return to your daily activities afterwards.
A day-by-day example for a cycle of around 28 days
This schedule is a general guide. The dates may differ if your cycle is shorter, longer or irregular, or if you are receiving treatment.
Day 1. The first day of full menstrual bleeding is usually counted as the start of the cycle. If you have light spotting beforehand, ask your doctor which day to record.
Days 2–5, if an initial scan is scheduled. Your doctor may assess the ovaries and uterine lining at the start of the cycle, especially before ovarian stimulation. An initial scan is not required every time a natural cycle is monitored.
Around days 9–12. This may be your first visit to check the dominant follicle. Your doctor measures it and decides when to see you again.
Over the following days. Depending on the findings, scans may be a day or several days apart. As ovulation approaches, the interval may become shorter. The number of visits varies from one patient to another.
After expected ovulation. If needed, a follow-up scan can assess the changes that have taken place. In some cases, your doctor may also order a hormone test.
Before you leave, confirm when your next scan will be and ask about the timing of intercourse in the meantime.
Estimating ovulation with a calendar, home tests or ultrasound
The calendar method uses the length of previous cycles to predict when ovulation might occur in the next one. It can give you a rough estimate, but it assumes that your cycle will follow its usual pattern. Ovulation does not always happen on day 14, even if your periods are usually regular.
Home ovulation tests detect a rise in luteinising hormone, known as LH, which usually precedes ovulation. A positive result suggests that ovulation is approaching, but it does not confirm that an egg has been released. If you have polycystic ovary syndrome, higher baseline LH levels can sometimes make the results harder to interpret.
Ultrasound monitoring shows how your ovaries change during the cycle you are in. If your calendar, home tests and scan suggest different timings, share the results with your doctor. A difference between them does not necessarily mean you have done anything wrong.
Signs of ovulation and how reliable they are
Possible signs of ovulation include an increase in clear, stretchy cervical mucus and a mild pulling sensation on one side of the lower abdomen. Some women do not notice these signs, and they can vary from month to month.
You can still ovulate without noticing characteristic discharge or pain. Basal body temperature rises after ovulation and is mainly useful for looking back at when it occurred. It is less helpful for planning intercourse in advance during the same cycle.
When to seek medical advice about ovulation pain
Typical ovulation pain can feel like a sharp twinge or a dull ache on one side and may last from a few minutes to a day or two. It cannot tell you exactly when the egg is released.
Severe pain, pain that is getting worse or pain that persists needs medical assessment. If the pain is sudden and severe, especially if you feel faint, have a fever or heavy bleeding, or could be pregnant, seek urgent medical help. These symptoms can have other causes and should not automatically be attributed to ovulation.
How does monitoring help you time intercourse?
The fertile window includes the five days before ovulation and the day of ovulation itself. The day or two before ovulation are particularly favourable. Sperm can survive for several days in the female reproductive tract, so fertilisation can occur after intercourse that takes place before the egg is released.
When trying to conceive naturally, having intercourse every one to two days during the fertile window increases the likelihood that viable sperm will be present at ovulation. If you are receiving treatment, follow your doctor’s specific instructions.
There is no need to time intercourse to a particular hour. If the planning starts to feel stressful, bring it up at your consultation. You can discuss which days matter without feeling that missing one opportunity means losing your chance for the whole month.
What happens if you are ovulating but have not become pregnant?
Knowing that you are ovulating is useful, but conception also depends on other factors. Folliculometry cannot confirm that the fallopian tubes are open or assess sperm. Repeating it should not delay a fertility assessment for both partners when one is needed.
A consultation for difficulty conceiving is usually recommended after 12 months of trying for women under 35 and after six months for women aged 35 or over. An earlier assessment is appropriate for women over 40. If you have irregular or absent periods, endometriosis or another known factor, you do not need to wait that long.
At Adella Clinic, you can discuss your cycle, how long you have been trying and any tests you have already had. The aim of the consultation is to understand what information is missing and what next step would be helpful for you.
Frequently asked questions
Can I start folliculometry while I am still on my period?
Yes. You can have a transvaginal scan during your period. An early visit is sometimes part of the initial assessment before treatment. If you have an appointment scheduled, check with the clinic about how to prepare before cancelling because of bleeding.
Is one scan enough to tell whether I have ovulated?
A single scan can give some indication of where you are in your cycle. Tracking follicle growth and the changes that follow often requires repeat scans. The number of visits depends on the medical question your doctor is trying to answer.
My follicle is 20–22 mm. Does that mean I will ovulate today?
A follicle of this size can suggest that ovulation is approaching, but it does not predict the exact day or hour. Your doctor considers it alongside previous measurements, the appearance of the uterine lining and, if needed, hormone test results.
Do I need another scan to check whether the follicle has ruptured?
A follow-up scan can be helpful when your doctor needs to determine whether ovulation has occurred. Ask if one is part of your plan. Seeing a developed follicle on an earlier scan does not confirm that it later ruptured.
Can an ovulation test be positive even if I do not ovulate?
Yes. The test detects a change in LH and cannot confirm that the egg has been released. If your doctor suspects a discrepancy, they may suggest ultrasound monitoring or a hormone test timed to the appropriate point in your cycle.
How is monitoring planned if my cycle is irregular?
The start date and follow-up visits are planned individually. Record the dates of your recent periods and show them to your doctor. If your cycles vary considerably, the cause of the irregularity also needs to be investigated.
Can I ovulate without pain or noticeable changes in discharge?
Yes. Ovulation can occur without noticeable symptoms. Conception is possible even if you do not experience all the signs described. If you are unsure, a medical assessment can give you more information than repeatedly comparing symptoms.
What does it mean if a follicle keeps growing without rupturing?
You may still ovulate, or the follicle may persist without releasing an egg. A single measurement is insufficient to draw a conclusion. Your doctor decides whether to repeat the ultrasound and order hormone tests before discussing treatment.
Do we need to try every day while ovulation is being monitored?
In a natural cycle, daily intercourse is usually unnecessary. Every one to two days during the fertile window is a reasonable guide. If you are undergoing ovarian stimulation or insemination, or have received specific instructions, follow your individual plan.
Can folliculometry show the quality of the egg?
No. It shows how the follicle develops and provides other ultrasound findings. The follicle’s size cannot directly indicate egg quality or guarantee that the egg will be fertilised.
Why is a progesterone test sometimes ordered after ultrasound monitoring?
A blood test can help determine whether you have ovulated recently. It is usually scheduled around a week before your expected period and does not always fall on day 21. A single result cannot assess how the corpus luteum functions throughout the period after ovulation.
How many cycles should we monitor before discussing other tests?
The number depends on your age, how long you have been trying and what the assessment has shown so far. At your first consultation, ask when you will review the plan and which tests it makes sense to carry out alongside monitoring.
