Ultrasound
The ultrasound generates images similar to x-ray without the accompanying radiation. Soft tissues reflect and absorb sound based upon their density and other factors. The ultrasound transducer emits sound into the body area being examined and collects the returned echoes which are interpreted by a computer and displayed on a monitor.
The vaginal probe is the most common type of ultrasound used in the infertility evaluation. The transducer (probe) is placed inside the vagina allowing the physician to examine the ovaries, the uterus, and other internal organs. The number and size of the follicles on the ovaries can be determined and the width of the uterine lining can be measured. Ultrasound is useful for evaluating other conditions including uterine abnormalities (fibroids, polyps, and congenital abnormalities), ovarian tumors, and for documenting pregnancy.
Patients undergo several vaginal ultrasounds when receiving ovulation induction drugs as in stimulated intrauterine insemination or in vitro fertilization. Medication dosages are adjusted based upon each patient's individualized response as measured by the size and number of follicles and estradiol hormone levels.
Luteal Phase Testing
The lining of the uterus (endometrium) thickens, and its blood supply increases, in order to accept and support a developing embryo. This development is primarily stimulated by the hormones estrogen and progesterone.
Some physicians choose to perform the endometrial biopsy to assess the development of the endometrium. In this test, a small sample (biopsy) of the endometrium is taken and examined under the microscope approximately twelve days after ovulation and prior to menstruation. Endometrial development should correlate with the cycle day and thus the endometrium should be thickened and vascular.
We choose to measure mid-luteal phase levels of progesterone rather than performing the endometrial biopsy. Seven to eight days after ovulation progesterone levels should be > 10ng/ml. We also assess the thickness of the endometrium via ultrasound measurements.
One reason the endometrium may not develop properly is because of low progesterone levels which can be due to poor egg development. If egg development is normal, progesterone may be administered during the luteal phase to provide additional support to the endometrium. If egg development is not normal, fertility drugs are used, often in combination with extra progesterone.