G.W.K. Tang

Long-term depot-medroxyprogesterone acetate and bone mineral density

The association between long-term use of depot-medroxyprogesterone acetate (DMPA) and bone mineral density (BMD) has been controversial, as seen in three case-control studies in New Zealand, Thailand, and the United Kingdom. In the present case-controlled study of BMD, a group of 67 Chinese women who had used DMPA from 5-15 years was compared with 218 women of the same age range who had not used any steroidal hormones. DMPA users were found to have a significantly lower BMD at lumbar vertebra (L2-4) (0.93 g/cm2), neck of femur (0.69 g/cm2), trochanter (0.59 g/cm2), and Wards triangle (0.58 g/cm2), as compared with the control group, whose corresponding BMD values were 1.03 g/cm2, 0.83 g/cm2, 0.71 g/cm2, and 0.78 g/cm2, respectively (p < 0.001). The average percentage of bone loss per year was estimated to be 1.1% in L2-4, 2.3% in neck of femur, 2.4% in trochanter, and 3.5% in Wards triangle. The percentage of bone loss in L2-4 was found to be more pronounced with age. This study provided information that the use of DMPA in a Chinese group for > 5 years in associated with bone loss, and a prospective study is needed to confirm these data, which are different from two case-control studies.

Levonorgestrel intrauterine device in the treatment of menorrhagia in chinese women: Efficacy versus acceptability

Ten Chinese women who had menorrhagia without organic cause and suffered from anaemia were treated with levonorgestrel intrauterine device for a total of 129 woman-months. There was a 54%, 87% and 95% reduction in menstrual blood loss at the first, third and sixth month of treatment when compared with the pretreatment cycle. These percentages of reduction were statistically significant, with p values of 0.004, 0.03 and 0.008, respectively. There was a median increase in menstrual cycle length of 12 days in nine months. Fifteen percent of the menstrual cycles were longer than 60 days. The total bleeding days increased by 4 days at the third menstrual cycles, but reduced to a median of 6 days at 6 months. Seventy-six percent of the menstrual bleeding was in the form of spotting. These Chinese women accepted such menstrual alterations. There was no hormonal side effects. All women preferred the device to hysterectomy. Levonorgestrel intrauterine device appeared to be an effective and acceptable treatment for menorrhagia in perimenopausal Chinese women.

Further evaluation on long-term depot-medroxyprogesterone acetate use and bone mineral density: a longitudinal cohort study

Cross-sectional studies on the effects of depot-medroxyprogesterone acetate (DMPA) on bone mineral density (BMD) have been controversial. The present longitudinal cohort study on 59 Chinese women over a period of 3 years has shown that their annual rate of bone loss at 3 sites (0.44% in lumbar spine, 0.40% in neck of femur, 1.05% in Wards triangle) was substantially less than the projected values (1.1% in lumbar spine, 2.3% in neck of femur, 3.5% in Wards triangle) in a cross-sectional study that had demonstrated a significant reduction in BMD in DMPA users than the non-user population. The trochanter BMD measurement did not show the projected annual bone loss of 2.4%. The rate of bone loss is probably non-linear, with a rapid loss in the first 5 years and a leveling off afterwards. The duration of DMPA use was not significantly correlated with the rate of bone loss. Multiple linear regression analysis demonstrated that age and body mass index were significant variables in modeling the rate of bone loss in the lumbar spine and neck of femur, but not in the trochanter and Wards triangle areas. The Z scores also suggested a retardation in bone loss with time and potentially due to the effect of progesterone in decreasing bone turnover that is similar to the situation in postmenopausal women. The present data provide another aspect of reassurance to the long-term use of DMPA.

Further acceptability evaluation of RU486 and ONO 802 as abortifacient agents in a Chinese population

Of 144 consecutive women who requested early induced abortion, 99 (68.7%) and 45 (31.3%) women chose RU486 combined with ONO 802 (medical method) and suction evacuation (surgical method), respectively. Logistic regression analysis of covariates showed that age and marital status were significantly correlated with the acceptability and hence the choice of the medical method. There were also more working women in this medical group. Previous experience of induced abortion had no influence on the current choice of the abortion method. This group of women appeared to have a tendency of treating their disease with medication rather than with surgery if the condition would allow. They expressed fear about surgery. The long induction-abortion interval of three days will have to be tolerated, but the duration of bleeding should be minimised in order to improve the acceptability of the drug. RU486 is an alternative abortion method which should be made widely available.

A pilot study of acceptability of RU486 and ONO 802 in a Chinese population

RU486 and ONO 802 in combination have been shown to be effective in early termination of pregnancy. Anecdotal information suggests that Chinese women have been using herbs to induce abortion, believing that such medication and means of abortion is less harmful to the body than surgery. Hence, a medical means of abortion using RU486 and ONO 802 may be the method of choice for some Chinese women. A pilot study involving 42 Chinese women in Hong Kong was conducted to explore the reasons for acceptance or refusal of RU486 and ONO 802 as abortifacient agents. It was found that more single women chose the medical method for abortion, the main reasons being fear of trauma to the body due to surgery and the feeling of having undergone menstrual regulation rather than having had an abortion with the medical method. Those who refused the treatment were worried about the efficacy and side effects of the new drugs and the long induction-abortion interval. There were 3 failures in the medical group of 23 women. All these 23 women were gland they had chosen the medical abortion method. Twenty-one out of the 23 women said they would choose the same abortion method again. The practice of the use of Chinese herbs was not more common in this group of women as compared to women who did not choose this method of abortion.

Relationships of Seminal Plasma Prolactin with Spermatozoal Characteristics and Fertilizing Capacity in Vitro

Seminal plasma prolactin (PRL) levels were determined in 224 semen samples collected from fertile and suspected infertile men, and their relationships with spermatozoal characteristics and fertilizing capacity in vitro were evaluated. PRL concentrations were similar in normospermic and oligospermic samples, but were significantly lower in azoospermic samples. PRL concentrations were significantly higher in samples with high spermatozoal motility than in those with low spermatozoal motility. There were no significant differences in PRL concentrations between normal-morphology and abnormal-morphology samples, and between high-fertilizing capacity and low-fertilizing capacity samples. A low degree of positive correlation was observed between the PRL concentration and the spermatozoal motility. There were no significant correlations between the PRL levels, the other spermatozoal characteristics, and the spermatozoal fertilizing capacity in vitro. These findings indicate that the seminal plasma PRL levels are significantly depressed in azoospermic subjects and suggest that the seminal plasma PRL may play a role in the maintenance of spermatozoal motility. Whether there is a potential function of prolactin in semen on spermatozoal fertilizing capacity, however, cannot be inferred from the present study.

Effects of androgens on fertilizing capacity of human spermatozoa.

The potential functions of testosterone and 5 alpha-dihydrotestosterone, the androgens normally present in human seminal plasma, on human spermatozoal physiology were evaluated by studying the effects of these two steroid hormones on the in vitro fertilizing capacity of human spermatozoa. Spermatozoa collected from presumably fertile men were washed in BWW medium and incubated with different concentrations (0, 100, 250, 500, 1000 pg/ml) of testosterone or 5 alpha-dihydrotestosterone for 5 hr before insemination of the zona-free hamster ova. Penetration of the zona-free hamster ova was scored 6 hr later and the results were analyzed statistically. Both testosterone and 5 alpha-dihydrotestosterone, at the concentrations tested, significantly decreased the in vitro penetration of the denuded hamster ova in comparison to the controls (p less than 0.05). A dose-dependent response was also observed for the 5 alpha-dihydrotestosterone tested. These findings indicate that exogenous testosterone and 5 alpha-dihydrotestosterone can inhibit the fertilizing capacity of human spermatozoa in vitro, and suggest that the androgens normally present in human seminal plasma may serve, in part, to prevent premature spermatozoal capacitation before the spermatozoa reach the site of fertilization in vivo.

Pre-operative cervical dilatation in termination of first trimester pregnancies using 16, 16-dimethyl-trans- Δ2 PGE1 methyl ester vaginal pessaries

The effect of a prostaglandin E1 analogue on the cervix prior to termination of first trimester pregnancy was studied in a double-blind placebo-controlled trial with 70 primigravid and 125 multigravid patients in the Hong Kong University Gynaecological Unit. One mg of 16, 16-dimethyl-trans-delta 2-prostaglandin E1 methyl ester (ONO 802) in the form of vaginal pessary was inserted 3 hours before vacuum aspiration. The cervical dilatation in patients receiving ONO 802 pessaries was significantly greater than that in patients who received no treatment or placebo pessaries but the difference in dilatation between patients who received no treatment or placebo was not significant. The blood loss during operation in patients receiving ONO 802 pessaries was also significantly less than that in patients receiving placebo pessaries. The side effects due to ONO 802 pessaries were mild and infrequent.

Spermatozoal Fertilizing Capacity in Polyzoospermia: a Preliminary Study

Summary:  Men with the spermatological symptom of polyzoospermia (> 250 times 106 sperm/ml) have been reported to seldom impregnate their wives. It was the aim of this study to investigate the spermatozoal fertilizing capacity in polyzoospermia by the human sperm and zona‐free hamster ova penetration bioassay. General semen characteristics and in vitro spermatozoal fertilizing capacity were studied in 12 polyzoospermic male partners of couples of infertile marriages. The results were compared with those from a control group of normospermic fertile men (n = 22). No significant differences in sperm motility, normal morphology and in vitro spermatozoal fertilizing capacity were found between the two groups. The polyzoospermic men we studied did not appear to have any defect with the spermatozoal fertilizing capacity, as assessed by the heterologous sperm ‐ ova penetration bioassay. The apparent impairment of fertility and higher abortion rate in couples with polyzoospermic male partners, as described in the literature, may be related to chromosomal aberrations and/or other unknown functional defect of the spermatozoa.

Seminal Plasma β-Human Chorionic Gonadotropin (β-HCG): Relationships with Seminal Characteristics and Spermatozoal Fertilizing Capacity

Summary:  Seminal plasma β‐human chorionic gonadotropin (β‐HCG) levels were determined in 254 semen samples collected from fertile and suspected subfertile men, and their relationships with seminal characteristics and spermatozoal fertilizing capacity were evaluated. Radioimmunoassayable β‐HCG, as defined by > 5 mlU/ml concentration, was demonstrated in only 44.5% of all the samples studied. β‐HCG concentrations were similar in normospermic, oligospermic and azoospermic samples. There were no significant differences in β‐HCG concentration between high‐motility and low‐motility samples, between normal‐morphology and abnormal‐morphology samples, and between high‐fertilizing capacity and low‐fertilizing capacity samples. No significant correlations between the concentrations of β‐HCG and individual parameters of semen analysis and spermatozoal fertilizing capacity among the various groups of samples were observed. The physiological role of seminal plasma β‐HCG is presently uncertain and the relationship of its determination to male fertility requires further investigation.