Medicolegal activity in obstetrical and gynaecological ultrasound.

We surveyed obstetricians who are members of the Australian Association of Obstetrical and Gynaecological Ultrasonologists for details of actions in which they had been asked to give an expert opinion between 1993 and 1998. We uncovered 50 cases, most of which involved missed fetal anomalies. Our findings suggest there is considerable medicolegal activity in obstetrical and gynaecological ultrasound in Australia.

Ectopic pregnancy--potentials for diagnosis using ultrasound and urine and serum pregnancy tests.

The ultrasound findings from 260 patients with a clinical suspicion of ectopic pregnancy have been analysed and correlated with the results of urine pregnancy tests and tests of serum LH and/or HCG levels. Most importantly in a practical clinical context, it was found that a negative serum test virtually excludes an ectopic pregnancy, and an empty uterus with an adnexal mass and/or the presence of free fluid together with a positive urine test gives a very high probability of an ectopic pregnancy. The absolute diagnosis of an ectopic pregnancy by the demonstration of a living fetus outside the uterus is an uncommon finding (8%). Conversely, an empty uterus alone on ultrasound examination in the absence of other ultrasound findings in those patients with a positive serum test is not a reliable guide to the presence of an ectopic pregnancy unless there is an irrefutable conception date at least 5 weeks previously. It is recommended that pathology laboratories and ultrasound departments establish absolute levels of HCG above which an intrauterine pregnancy should always be visible within the uterus. Given appropriate attention to the clinical condition of the patient, the combined use of diagnostic ultrasound, simple urine pregnancy tests and serum assays of beta HCG levels goes a long way to discriminating between those patients with and those without an ectopic pregnancy.

Use of ultrasound in monitoring ovulation induction with human pituitary gonadotropins.

Serial follicular growth was studied using real-time ultrasound scanning in 26 anovulatory patients in 55 cycles stimulated with exogenous human pituitary gonadotropin (hPG) and human chorionic gonadotropin (hCG). Dosage was monitored with urinary total estrogen estimations. The ultrasound findings were not made known to the attending physician. Forty-four cycles (80%) were ovulatory, and conception occurred in 13. The mean follicular diameter of 17 to 25 mm at ovulation corresponded with the range observed in spontaneous cycles, although the rate of follicular growth was faster with hPG. On the day the ovulatory dose of hCG was given, as determined by the first urinary estrogen value greater than 50 microgram/24 hours, estrogen excretion was similar whether single or multiple follicles of potential ovulatory size were present, but mean follicular diameters were significantly smaller when there was more than 1 follicle. During the last 4 days before ovulation, the mean diameters in conceptual cycles increased from 14.2 mm to 19.7 mm, values similar to those observed in spontaneous cycles, but different growth patterns occurred in some nonconceptual cycles. Ovarian hyperstimulation was identified by ultrasound scan in 4 of 5 cycles before urinary estrogen excretion exceeded the normal range. Although ultrasound scan does not supplant estrogen monitoring, it can assist in the early detection of hyperstimulation, in the more accurate timing of the ovulatory dose of hCG, and in the withholding of hCG when 3 or more ovulations are possible. It is recommended that ultrasound examination be performed in all patients before the ovulation-inducing dose of hCG is given to provide information on the number of follicles that are likely to ovulate and thus avoid conception of more than twins.

Ultrasound in an in vitro fertilization program.

Ultrasound examinations of the preovulatory follicle were performed on 39 patients in 58 consecutive spontaneous cycles in which ovum aspiration for in vitro fertilization was planned. Examinations during the follicular phase helped to indicate when patients should be admitted for intensive monitoring of urinary luteinizing hormone (LH) levels and as a means of lateralizing the side of follicular development in those patients in whom one ovary was known to be inaccessible to laparoscopic aspiration. The technique was also of value in determining whether ovulation had occurred in those patients in whom the anticipated midcycle LH surge was not detected and as a routine measure prior to laparoscopy to ensure the continuing presence of the follicle.

Monitoring ovarian follicular development with real-time ultrasound.

Ovarian follicular growth during the periovulatory period was measured using real-time ultrasound in 33 patients during 53 spontaneous ovulatory cycles. The mean follicular diameter increased from 14.1 mm four days before ovulation to a maximum of 20.1 mm on the day of presumptive ovulation. The results correspond with previous static ultrasound studies of follicular development and in nine cycles in which both methods were employed the correlation between measurements on the same day was highly significant (r = 0.944; p < 0.001). The day of ovulation could not be anticipated from a single measurement because of the relatively wide range of follicular size. Except in some obese subjects, real-time ultrasound examination of the developing follicle appears to be a useful technique for assessing the progress of the ovarian cycle.

Perinatal mortality and morbidity in breech presentation.

The perinatal mortality associated with breech presentation at the Royal Women's Hospital, Melbourne, between 1974 and 1976 was 10.4%, or almost 5 times the overall hospital figure. Nine of 487 infants (1.8%) weighing greater than or equal to 2500 g died in the perinatal period, but 7 were already dead at the onset of labor or had congenital abnormalities incompatible with life. Sixty of 177 infants (33.9%) weighing 1000-2499 g died in the perinatal period, but 28 of these died due to prematurity alone or from complications of intrauterine hypoxia or birth trauma. Although elective cesarean section for breech presentation could not be justified for infants weighing greater than or equal to 2500 g, this procedure may well reduce the perinatal loss of premature infants by reducing the incidence of intrauterine hypoxia and preventing birth trauma.