Colin D. Matthews

Failure of body mass index or body weight to influence markedly the response to ovarian hyperstimulation in normal cycling women

A retrospective analysis was performed of 368 normally cycling women treated with a single cycle of a standard ovarian hyperstimulation regime (CC 100 mg days 5 to 9 and hMG 150 IU days 6, 8, and 10) associated with either an IVF or GIFT program. Neither the peak serum E2 level attained nor the number of days of stimulation required bore a relationship to the BMI or the total body weight of these women. Whereas the mean number of oocytes aspirated from women with BMI less than 19.1 was higher (6.4 +/- 3.2) compared with obese women (BMI greater than 27.6, 4.8 +/- 2.6), the rate of fertilization was not different for both BMI extremes. It is concluded that factors other than BMI or total body weight have more important influences on the response to hyperstimulation in normal women.

Predicting me Luteinizing Hormone Surge: Relationship Between me Duration of me Follicular and Luteal Phases and the Length of the Human Menstrual Cycle

Determination of blood serum levels of luteinizing hormone (LH) are used to detect the day of the midcycle surge. This information, collected over several menstrual cycles of numerous women, is used to derive mathematical expressions relating the day of the surge to the length of the cycle. The equations are subsequently employed to predict the most likely day of the LH surge, and hence the time of ovulation, solely from knowledge of the average length and variability of a womans cycles, without the need for determinations of LH. A convenient table is provided for making this prediction.

Human plasma melatonin and urinary 6‐sulphatoxy melatonin:studies in natural annual photoperiod and in extended darkness

Summary. Objectives The alms of the study were (1) to examine the human plasma melatonin rhythm at the equinoxes and the solstices in the natural photoperlod (35.S); (2) to examine melatonin rhythms in the same subjects under extended darkness conditions to expose any suppressive (gating) effects of light at any time of the year; (3) to undertake a rigorous examination of the relationship between plasma melatonin and the urinary metabolite 6‐suiphatoxy melatonin at varying times of the year.

Prediction of in vitro fertilization rates from semen variables

OBJECTIVE To assess the value of semen variables for predicting fertilization rates. DESIGN Measures of the fresh semen and the motile sperm fraction used for insemination were related to the fertilization rate by multiple regression analysis. The regression model was then used to construct a two-dimensional clinical chart. SETTING University-affiliated reproductive medicine unit. PATIENTS The results of 294 IVF cycles were analyzed retrospectively. Selection criteria were: [1] first cycle of IVF; [2] tubal and/or male factor infertility; and [3] four or more oocytes inseminated. INTERVENTIONS None. MAIN OUTCOME MEASURES The fertilization rate was related to measured variables of the fresh semen and the motile sperm fraction used for insemination. Fertilization rate was categorized as poor (< 35%) or acceptable (> or = 35%). RESULTS Multiple regression analysis demonstrated a strong correlation between the fertilization rate and the combined indexes of percentage normal morphology and grade of motility in the fresh semen and percentage progressive motility in the motile sperm fraction. A two-dimensional chart that expressed these relationships was constructed. Its accuracy of prediction was 77% for poor fertilization and 95% for acceptable fertilization. CONCLUSIONS The fertilization rate is strongly correlated with percentage normal sperm morphology in the fresh semen and the percentage progressive motility in the motile sperm fraction used for insemination. The clinical chart provides a simple but powerful tool for predicting fertilization outcome.

Plasma melatonin in the horse: Measurements in natural photoperiod and in acutely extended darkness throughout the year

Abstract: Plasma melatonin was measured at the winter and summer solstices and the autumn and spring equinoxes in four mares held under natural conditions at 35°S. At all seasons the onset of the nightly elevated melatonin was coincident with or after the time of sunset and the melatonin offset after the time of sunrise. The duration of elevated melatonin was not different from the duration of natural scotophase for each season, with the duration of elevated melatonin longer in winter than the other seasons. Immediately following each 24 hr sampling two mares were resampled in acutely extended darkness to determine the melatonin profile of the endogenous rhythm of the circadian pacemaker, originating from the suprachiasmatic nuclei (SCN). At each season melatonin secretion commenced earlier and decreased later than that measured under the natural photoperiodic condition, suggesting that the expression of the melatonin rhythm is normally gated by natural environmental light both at dusk and dawn. The interval from the onset of melatonin measured under acutely extended darkness to the time of sunset was greater in the spring/ summer than the autumn/winter suggesting a possible alternating signal throughout the year. Thus the mare appears to exhibit a similar interaction between endogenous circadian rhythmic activity and the natural photoperiod as the ewe which may underlie the mechanism for timing reproductive activity through the year.

A fluorescent in situ hybridization analysis of the chromosome constitution of ejaculated sperm in a 47, XYY male

Two semen samples from a 47, XXY male were examined using chromosome‐specific DNA probes and fluorescent in situ hybridization (FISH) to determine the distribution of sex chromosomes and an autosome (chromosome 17) in the sperm. A motile population of sperm was also prepared from one sample using the swim‐up technique to compare the motile and total sperm populations. Chromosomes were localized using single FISH and a biotinylated chromosome 17 probe (TR17), or double FISH using a biotinylated X chromosome probe (TRX) and a digoxigenin‐labelled Y chromosome probe (HRY). Labelling efficiencies were 95–98%. Ploidy levels were estimated by measurement against a microscope eyepiece graticule. The overall ratio of X‐to Y‐bearing sperm was 47% to 48.4% in the neat samples, and 48.4% to 45.3% in the swim‐up fraction. Neither of the ratios was significantly different from 1:1. The frequencies of monosomic and disomic (but otherwise haploid sperm) were not different from the frequencies we observed in normal donors. In contrast, the frequencies of both diploid and tetraploid cells were increased in the neat samples of the XYY male. In the swim‐up fractions, however, none of these parameters differed from those of ten normal semen donors. These results support the hypothesis that the extra Y chromosome in XYY men is eliminated during spermatogenesis.

Detection of X- and Y-bearing human spermatozoa after motile sperm isolation by swim-up

OBJECTIVE To assess the ratio of X- to Y-bearing human spermatozoa in motile fractions isolated by the swim-up technique. DESIGN The proportions of X- and Y-bearing sperm were determined in neat semen samples (control) and in motile fractions isolated from the same samples by swim-up. X- and Y-bearing sperm were simultaneously identified using chromosome-specific DNA probes and double fluorescence in situ hybridization. SETTING Hospital-based university department. PARTICIPANTS Ten healthy donors with normal semen characteristics. MAIN OUTCOME MEASURES The distribution of haploid cells (X or Y), normal size cells with two sex chromosome (XX, YY, or XY), and large cells containing two (XX, YY, or XY) or four (XXYY) sex chromosomes were measured in neat semen samples and in motile fractions prepared by swim-up. RESULTS Overall, 95% of sperm in the neat semen and swim-up fractions were labeled with the probes. The ratios of X- to Y-bearing sperm were 47.3:46.9 (neat semen) and 48.4:47.1 (swim-up fractions), which were not significantly different from a 1:1 ratio. The frequencies of sperm with normal size nuclei and two sex chromosomes (XX, YY, or XY) in the swim-up fractions were not significantly different from the controls, but there was a significant reduction in the proportion of cells with large nuclei and two (XX, YY, or XY) or four (XXYY) sex chromosomes in the swim-up fractions. CONCLUSIONS The swim-up technique does not selectively enrich either X- or Y-bearing sperm. Because the isolation of motile spermatozoa is an important procedure for routine IUI, IVF-ET, and GIFT, the results of this study are important reassurance that the sex ratio is not altered by this method of sperm preparation.

Inhibin and relaxin concentrations in early singleton, multiple, and failing pregnancy: relationship to gonadotropin and steroid profiles

Objective To examine the inter-relationships between inhibin, relaxin, steroid concentrations, estradiol (E 2 ), progesterone (P), and gonadotropins in early pregnancy. Design Hormone concentrations in plasma were measured during the luteal phase of subjects who became pregnant (n=58) or failed to become pregnant (n=47) after ovarian hyperstimulation for in vitro fertilization-gamete intrafallopian transfer (IVF-GIFT) (group 1). A further group of subjects became pregnant (n=7) or failed to become pregnant (n=8) during endocrinology tracking of a natural cycle (group 2). Blood was obtained every 3 days in the luteal phase from day 5 in group I (day 0 was oocyte recovery) and from day 0 (first increase in luteinizing hormone [LH]) in group II. Results Progesterone and E 2 were increased over nonpregnant values by day 11 (P) and day 16 (E 2 ) in group I and by day 11 (E 2 and P) in group II. Inhibin and relaxin concentrations were significantly increased by day 16 in group I (often by day 11) and by day 14 in group II pregnancy subjects. A direct relationship existed between inhibin, P, relaxin, and human chorionic gonadotropin (hCG). Subjects who had twin pregnancies demonstrated higher concentrations of all hormones and often exhibited increases earlier (by day 11 in group I) than singleton pregnancy subjects. Pregnancies that ended in miscarriages tended to have lower concentrations of P and inhibin. None of the hormones reliably discriminated between the clinical conditions of blighted ovum and of spontaneous abortion, and the predictive value of any hormone measured for miscarriage was not high. Conclusions The trend of inhibin and relaxin concentrations closely parallels rises in P during early pregnancy. Luteinizing hormone (LH) and follicle-stimulating hormone (FSH) levels are suppressed very early in pregnancy. The suppression of LH and FSH in hyperstimulated cycles is more governed by E 2 than inhibin in stimulated cycles. Some subjects destined to miscarry exhibit abnormal endocrine changes very early in the luteal phase.

The Variability in Circadian Phase and Amplitude Estimates Derived from Sequential Constant Routines

Both the constant routine (CR) and the dim light melatonin onset have been suggested as reliable methods to determine circadian phase from a single circadian cycle. However, both techniques lack published studies quantifying the intercycle variability in their phase resolution. To address this question eight healthy male subjects participated in two CRs, 7 days apart. Circadian phase was determined using 3-min samples of core body temperature and two hourly urinary sulphatoxy melatonin excretion rates. Phase and amplitude were estimated using simple (24 h) and complex (24 + 12 h) cosinor models of temperature data and the onset, offset, and a distance-weighted-least-squares (DWLS) fitted acrophase for the melatonin metabolite. The variability in phase estimates was measured using the mean absolute difference between successive CRs. Using the simple 24 h model of temperature data, the mean absolute phase difference was 51 min (SD = 35 min). Using the complex model, the mean absolute phase difference was 62 min (SD = 35 min). Using the DWLS fitted acrophase for the melatonin metabolite, the mean absolute phase difference between CR1 and CR2 was 40 min (SD = 26 min). The results indicate that for CRs a week apart, the mean absolute difference in an individuals phase estimate can vary by 40-60 min depending on the choice of dependent measure and analytic technique. In contrast to the intraindividual variability, the group results showed considerably less variability. The mean algebraic difference between CRs, using temperature- or melatonin-derived estimates, was less than 5 min, and well within the range of normal measurement error.

Assessment of the separation of X- and Y-bearing sperm on albumin gradients using double-label fluorescence in situ hybridization.

OBJECTIVE To determine the ratio of X- to Y-bearing human spermatozoa in fractions isolated from discontinuous albumin gradients. DESIGN The proportions of X- and Y-bearing sperm were determined in neat semen samples (control) and in albumin-separated fractions from the same samples. Two albumin methods were used: a two-layer method (experiment 1) and a three-layer method (experiment 2). X- and Y-bearing sperm were identified simultaneously using chromosome-specific DNA probes and fluorescence in situ hybridization. SETTING Hospital-based university department. PARTICIPANTS Healthy donors with normal semen characteristics. MAIN OUTCOME MEASURES The proportions of haploid cells (X or Y) and cells with two sex chromosomes (XX, YY, or XY) were determined. RESULTS Labeling efficiencies were > 96% in all samples. Control samples showed a 1:1 ratio of X- to Y-bearing sperm. Fractions isolated on albumin gradients showed a slight, but statistically significant enrichment of X-bearing sperm. This was evident with both albumin methods. CONCLUSIONS Discontinuous albumin gradients do not enrich Y-bearing sperm as previously reported.