Baseline Fertility Testing: What It Measures

What Is Baseline Fertility Testing?

Baseline fertility testing is performed early in the menstrual cycle or at the beginning of a fertility treatment cycle to establish an initial picture of ovarian and hormonal activity. Depending on the purpose of testing, it may include bloodwork, a transvaginal ultrasound or both.

During fertility treatment, baseline testing can help confirm that the ovaries and hormone levels are appropriate for the planned cycle. During a fertility evaluation, similar early-cycle testing may provide information about ovarian reserve and reproductive function.

When Is Baseline Testing Performed?

Baseline testing is commonly scheduled during the first few days of the menstrual cycle, although the exact timing and tests ordered depend on the clinical situation. Your fertility team will provide instructions based on whether testing is being performed for diagnostic purposes or as part of an IUI, IVF or other treatment cycle.

What Bloodwork Is Included in Baseline Testing?

Baseline bloodwork is selected based on the purpose of the evaluation or treatment cycle. During early-cycle fertility testing, hormone measurements may help establish an initial picture of ovarian activity and reproductive function.

FSH and Estradiol

FSH and estradiol are often measured early in the menstrual cycle. FSH is involved in stimulating follicle development, while estradiol is produced by developing follicles. The two values may be considered together when evaluating early-cycle ovarian activity.

Other Hormone Testing

Depending on the clinical situation, baseline bloodwork may include additional hormone measurements. AMH, for example, may be used as part of ovarian reserve assessment, while other tests may be ordered based on medical history, symptoms or treatment plans.

The exact panel is individualized. A fertility specialist interprets baseline bloodwork alongside ultrasound findings, age, reproductive history and other fertility testing rather than using a single hormone result to make treatment decisions.

What Does a Baseline Ultrasound Evaluate?

A baseline transvaginal ultrasound allows the fertility team to evaluate the ovaries and uterus at the beginning of a menstrual or treatment cycle. The findings provide information that complements baseline bloodwork.

Ovaries and Antral Follicles

The ultrasound can identify and count small antral follicles in the ovaries. This antral follicle count is one measure of ovarian reserve and may help physicians anticipate how the ovaries could respond to fertility medications.

Ovarian Cysts or Other Findings

Baseline ultrasound may identify ovarian cysts or other findings that could be relevant before treatment begins. Not every cyst requires treatment or a change in plans; its significance depends on its appearance, size, hormone activity and clinical context.

Uterus and Endometrial Lining

The ultrasound also provides information about the uterus and endometrial lining. During a treatment cycle, these findings can help the clinical team determine whether the cycle appears ready to proceed as planned.