Evaluation of an experimental system for the in vitro assessment of ultrasonic contrast agents.

The ultrasonic properties of microbubble contrast agents need to be fully understood if reproducible images and quantitative results are to be produced. Additional aspects of the physical and chemical environment into which the contrast agents are introduced also need to be taken into account, and their effect on contrast agent performance evaluated. A setup that provides an accurate and reproducible data-acquisition system is presented and evaluated in this paper. The linear range of this system is assessed, as well as its accuracy and precision. A new approach to the investigation of contrast agents, based on normalised backscatter, is discussed. Also, a common technique of degassing, widely used in other areas, is described and evaluated to determine its appropriateness to contrast agent studies.

The predictive value of computer-assisted semen analysis in the context of a donor insemination programme.

In this paper we examine the value of both conventional and computer-assisted semen analysis (CASA) using the Hamilton-Thorn HTM-S 2030 in predicting the in-vivo fertility of cryopreserved donor semen. Semen samples were examined prospectively and data on the conventional criteria of semen quality, sperm morphometry and movement were collected. Of 61 ejaculates identified, 33 achieved pregnancies ('successful') and 28 failed to do so ('unsuccessful'), despite insemination into at least four different normal female recipients. When the post-thaw semen profiles were compared, no differences were observed between the two groups in respect of the conventional criteria of semen quality determined by conventional laboratory techniques; however, there were differences in respect of both morphometry and movement characteristics determined by the HTM-S. When multiple logistic regression was used to examine the ability of the variables measured to predict the achievement of pregnancy, the conventional criteria of semen quality were of no value (chi 2 = 6.67, P = 0.353). However, the CASA assessment successfully predicted outcome in 86.9% of cases (chi 2 = 44.3, P = 0.0021). It was concluded that CASA assessment is of significant value in predicting the ability of an ejaculate to achieve pregnancy.

A prospective clinical study of the relationship between the computer-assisted assessment of human semen quality and the achievement of pregnancy in vivo.

The objective of this study was to examine the clinical predictive value for the achievement of pregnancy in vivo of the assessment of human semen quality by computer-assisted semen analysis using the Hamilton-Thorn Motility Analyser (HTM-S), alongside classic World Health Organization (WHO) techniques. A prospective follow-up study of 303 couples attending a regional infertility clinic providing tertiary level services to the population of a single geographical region was undertaken. Couples attending the infertility clinic, in whom the female partner was normal on conventional investigations (history, examination, evidence of ovulation, laparoscopy), were studied. After initial assessment, couples were followed for a median of 15 months and treatment-independent pregnancies observed and related to the results of semen assessment. During the period of follow-up, the treatment-independent pregnancy rate was 52%. Several measures of semen quality, determined both manually and by the HTM-S, were found to be predictive of the achievement of pregnancy and were related to the time taken to conceive. Couples who conceived had higher sperm concentrations and motilities, determined both manually and by the HTM-S, as well as differences in sperm head morphometry and sperm velocity determined by the HTM-S. Using multiple logistic regression, the prognostic accuracy of the HTM-S alone was similar to manual techniques, although data from the computer assisted sperm analysis system were preferred. Using proportional hazards regression, several variables were related to the achievement of pregnancy, particularly morphometry and motility. It was concluded that a strong case can be made for the introduction of automated assessment of human semen in routine service andrology laboratories.

Assessment of the conventional criteria of semen quality by computer-assisted image analysis: evaluation of the Hamilton-Thorn motility analyser in the context of a service andrology laboratory.

A comparative assessment of the conventional criteria of semen quality (sperm concentration, motility and morphology) was undertaken by standard laboratory techniques and by means of a computer-assisted image analysis system (the Hamilton-Thorn HTM-S 2030) in an open prospective study, in the context of a service andrology laboratory. A total of 1435 semen samples submitted by couples in the course of routine infertility investigations were examined by both methods, and the results compared. It was observed that the method did not provide comparable data on semen quality, either in respect of sperm concentration or graded motility, while the morphometric data generated by the HTM-S did not appear to be related to conventional morphology assessment. The clinical value of such systems in the assessment of the classical determinants of semen quality requires formal assessment in properly conducted large scale prospective studies.

The interaction of parameters of male and female fertility in couples with previously unexplained infertility.

A prospective study was undertaken of the relationship between semen variables, serial endocrine and follicular ultrasound measurements in one complete menstrual cycle, and the treatment-independent chance of conception for couples who were referred with unexplained infertility. For the 91 couples studied, the mean length of infertility was 70 months. A 100% follow-up rate was achieved. When a stepwise analysis was performed examining semen variables and ultrasonographic and endocrine variables, the mean ratio of salivary progesterone/plasma estradiol between days +1 and +3, with respect to the luteinizing hormone surge and the Grade 2 motile sperm density, were the only variables that achieved the 5% level of significance. There was a highly significant relationship between the product of these two variables and the chance of conception. This study clearly demonstrates an interaction between parameters of male and female fertility.