The role of ultrasound in female infertility management

Abstract

Ultrasound became an important help for the diagnosis of infertility by demonstration of the pelvic organs, of growing ovarian follicles, of intrafollicular structures and of cyclic uterine endometrial changes. Ultrasonic particularities of ovaries and their landmarks such as the ovarian artery, are described. Average ovarian blood flow can be measured. In hormone stimulated cycles, the ultrasonic examination is repeated through ovulation, induction and even afterward. The average diameter of the growing follicle is measured. The results of more than 8000 scans allowed the deduction that ovulation induction would be successful if the preovulatory follicular diameter was between 18 and 24 mm. Where two or more follicles of that diameter are present, multiple pregnancy occurs. The risk of overstimulation can be assessed. The importance of ultrasound is even higher than estradiol because it is impossible to differentiate between one big, some medium or many small follicles with hormone assays. It is possible to see the cumulus oöphorus, but not earlier than 1–2 days before ovulation. Following successful ovulation the mature follicle appears to have a more solid than cystic make-up. Signs of a failure of ovulation are given. Cyclic changes in the histology of the endometrium are described and make it possible to predict ovulation within 12 hr. Ultrasound is an important aid in predicting the time of ovulation more accurately than the basal body temperature and faster and cheaper than hormone profiles. Ultrasound plays a role in egg collection and replacement of the embryo. The detection of ovulation is very important in the treatment of infertility. This was only possible for a longtime by hormone profile. Nowadays ultrasound is an accepted method in the diagnostic procedures of this field. It permits the visualization of the position and size of the uterus, Fallopian tubes and ovaries, the exclusion of genital anomalies and the demonstration of physiological changes of these organs during the menstrual cycle. The main points of ultrasound in the diagnosis of infertility are as follows: 1. (1) Demonstration of the pelvic organs (uterus, Fallopian tube, ovary) and vascular structures. 2. (2) Demonstration of growing ovarian follicles (Measurement of their numbers and sizes). 3. (3) Demonstration of intrafollicular structures (Cumulus oöphorus, Corpus luteum). 4. (4) Demonstration of cyclic uterine endometrial changes. Most of the results were first obtained with high-resolution compound scanners, but the new generation of real-time scanners are equally capable. Sector scanners are superior to linear-array-parallel scanners, especially for the demonstration of specific structural changes within the uterus and ovary. The full-bladder technique is the most important precondition of examinations of the small pelvis.