From the Guidelines
A normal antral follicle count (AFC) for a 33-year-old woman typically ranges from 10 to 20 total follicles when counting both ovaries combined. This count represents the number of small follicles (2-10 mm in diameter) visible on transvaginal ultrasound during the early follicular phase of the menstrual cycle. At age 33, most women still maintain good ovarian reserve, though there can be considerable individual variation. AFC is an important marker of ovarian reserve and potential fertility, with higher counts generally associated with better reproductive outcomes. The count naturally declines with age as the primordial follicle pool diminishes.
According to the most recent and highest quality study available 1, the follicle number per ovary (FNPO) is a significant indicator of ovarian reserve. However, this study does not provide a specific normal range for AFC in a 33-year-old woman. Another study 1 discusses the relationship between AFC and the risk of miscarriage but does not provide a normal range for AFC either.
Given the information available, the normal range for AFC can be inferred from general knowledge and previous studies. If a 33-year-old woman has an AFC below 7, this might indicate diminished ovarian reserve and warrant further evaluation with other tests like anti-Müllerian hormone (AMH) levels and follicle-stimulating hormone (FSH) testing. AFC assessment should ideally be performed during days 2-5 of the menstrual cycle for the most accurate results.
Key points to consider:
- AFC is a significant indicator of ovarian reserve and potential fertility.
- The count naturally declines with age.
- An AFC below 7 might indicate diminished ovarian reserve.
- Further evaluation with other tests like AMH and FSH may be necessary for women with low AFC.
- AFC assessment should be performed during days 2-5 of the menstrual cycle for accurate results.
From the Research
Antral Follicle Count (AFC) in 33-Year-Old Females
- The AFC is known to decrease with age, with studies indicating a linear decline 2, 3.
- A study published in 2011 found that for every year increase in age, the median AFC decreases by 0.4 3.
- Another study from 2017 reported that AFC decreases by 0.79 follicles per year of age 2.
- The normal values for AFC in women with regular menstrual cycles have been established, with a nomogram reporting normal and interquartile values for AFC, age by age, throughout the reproductive period 3.
- For a 33-year-old female, the expected AFC can be estimated using the nomogram, which shows a decline in AFC with age 3.
Age-Related AFC Nomograms
- Age-related nomograms for AFC have been developed to provide a reference chart for fertility practitioners 2, 3.
- These nomograms show an approximately linear pattern, inversely correlated with age, regardless of the percentile 2.
- The nomograms can be used to counsel patients on a scientific basis, providing a more accurate assessment of ovarian reserve 3.
Comparison of AFC in Different Populations
- A study comparing AFC in women with polycystic ovary syndrome (PCOS) and age-matched controls found that AFC declines with age in both groups, but the decline is exponential and faster in non-PCOS women 4.
- Another study found that AFC decreases with age in subfertile Chinese women in Singapore, with a linear decline 2.