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Biomedical subjects

O S Tang

Publications and source records attributed to O S Tang.

At least 19 recordsLinked to original sources
PubMed2005

A prospective, randomized, double-blind study to compare two doses of recombinant human chorionic gonadotropin in inducing final oocyte maturity and the hormonal profile during the luteal phase.

CONTEXT: Different doses of human chorionic gonadotropin (hCG) have been used in various in vitro fertilization (IVF) treatment protocols to achieve final oocyte maturation. There is as yet no agreement on the optimum dose required. OBJECTIVES: The objective of this study was to compare the effectiveness of 250 and 500 microg recombinant hCG (r-hCG), which represented the lower and upper limits of the dose range, in inducing final oocyte maturation during IVF and intracytoplasmic sperm injection cycles. DESIGN: This was a prospective, randomized, double-blind study. SETTING: This study was performed at an IVF clinic in a teaching hospital. PATIENTS: Sixty patients with an indication for intracytoplasmic sperm injection were studied. INTERVENTION: The treatment dose used was 250 or 500 microg r-hCG. MAIN OUTCOME MEASURES: The percentage of metaphase II oocytes retrieved per patient, as an indicator of oocyte maturation, and the hormone profiles of the treatment cycle starting from the day of hCG up to hCG+10 d were the main outcome measures. RESULTS: The percentage of metaphase II oocytes was similar in the two groups (89.3% vs. 86.0%; P = 0.326) despite higher serum and follicular fluid hCG levels on hCG+2 and hCG+4 d, as was the follicular fluid to serum hCG ratio in the 500-microg r-hCG group. Serum estradiol and progesterone levels were comparable initially, but became significantly higher in the 500-microg r-hCG group on hCG+10 d. CONCLUSION: The two doses of r-hCG were equally effective in inducing final oocyte maturation. It remains unclear whether the higher midluteal estradiol and progesterone levels in the 500-microg r-hCG group confer any benefit.

Adult↗
PubMed2004

Intracervical sodium nitroprusside versus vaginal misoprostol in first trimester surgical termination of pregnancy: a randomized double-blinded controlled trial.

BACKGROUND: Results from small-scale randomized studies on the effectiveness of different preparations of nitric oxide donors in cervical priming before first trimester termination of pregnancies are not consistent. We compared sodium nitroprusside gel to misoprostol, the standard agent for cervical priming in this randomized double-blinded controlled trial. METHODS: Two hundred pregnant patients between 8 to 12 weeks admitted for surgical termination of pregnancy were recruited. They were randomized into either 400 microg vaginal misoprostol and intracervical placebo gel, or 10 mg intracervical sodium nitroprusside gel and placebo tablets 3 h before the procedure. The baseline cervical dilatation and cumulative force required to dilate the cervix from 4 to 9 mm were measured with a tonometer. Blood pressure was measured and side effects were assessed. RESULTS: The cumulative force to dilate the cervix from 4 to 9 mm was significantly higher in the sodium nitroprusside group, and the difference remained when a sub-group analysis was performed according to parity. Baseline cervical dilatation, duration of operation and operative blood loss were all in favour of misoprostol. Transient drop in blood pressure was observed after sodium nitroprusside treatment. CONCLUSIONS: Intracervical sodium nitroprusside is not as effective as misoprostol in cervical priming.

Abortifacient Agents, Nonsteroidal↗
PubMed2004

A pilot-randomized comparison of sublingual misoprostol with syntometrine on the blood loss in third stage of labor.

BACKGROUND: To compare sublingual misoprostol with intravenous syntometrine use during third stage of labor by measuring the blood loss. METHODS: Sixty women were randomized to receive either 600 micro g misoprostol sublingually or 1 ml syntometrine intravenously during the third stage of labor after spontaneous vaginal delivery. For those with risk factors of postpartum hemorrhage such as medical induction or augmentation of labor, previous third stage complications were excluded. The blood loss in labor was measured by the alkaline-hematin method, and differences in hemoglobin before and after delivery were compared. RESULTS: There was no significant difference in the median measured blood loss between the misoprostol group and the syntometrine group (280 versus 226 ml, p = 0.45). The change in hemoglobin was comparable between the two groups. There were more women in the misoprostol group who required additional oxytocics, but the difference was not statistically significant. A major complication occurred in one patient in the misoprostol group with blood loss in excess of 1000 ml. The incidence of side effects such as shivering and pyrexia in women receiving misoprostol was significantly higher than that in the syntometrine group. CONCLUSION: The use of sublingual misoprostol or intravenous syntometrine in spontaneous vaginal delivery resulted in a comparable amount of blood loss. Transient side effect such as fever and shivering which resolved within a day occurred more frequent to those who received sublingual misoprostol.

Administration, Sublingual↗
PubMed2001

Second trimester medical abortion with mifepristone and gemeprost: a review of 956 cases.

The treatment outcomes of 956 women undergoing second trimester termination of pregnancy with mifepristone and gemeprost were studied. The median gestational age was 16 weeks (range: 12-24 weeks). All women were treated with 200 mg mifepristone orally, followed 36 h later with 1 mg vaginal gemeprost administered every 6 h to a maximum of 4 doses in the first 24 h. A second course of 1 mg vaginal gemeprost was given 3-hourly in the next 12 h, if abortion had not occurred. Overall, 96.4% and 98.8% of the women aborted within 24 and 36 h, respectively. The median induction-to-abortion interval was 7.8 h (range: 0.5-109.9 h). The induction-abortion interval was longer in nulliparous women and women with a gestation age 17 weeks or above. Surgical evacuation of the uterus was performed in 11.5% of women for incomplete abortion or retained placenta. More multiparous women (16.7%) required surgical evacuation of uterus than did nulliparous women (7.3%; p <0.001). Ten (0.1%) women failed to abort with gemeprost and required other methods for abortion. In conclusion, a combination of mifepristone and gemeprost is a safe, effective, and noninvasive method of medical abortion for second trimester pregnancy.

Abortifacient Agents, Nonsteroidal↗
PubMed2001

Pilot study on the use of sublingual misoprostol for medical abortion.

A new route of sublingual administration of misoprostol was used by 25 women with first trimester, non-viable intrauterine gestation and by 18 women requesting mid-trimester termination of pregnancy. Twenty-three women (92%, 95% CI 75, 98) with first trimester, non-viable gestation had complete abortion after sublingual misoprostol. All women (100%, 95% CI 82, 100) requesting second trimester abortion aborted, and the median induction-to-abortion interval was 11.6 h. Our preliminary results on sublingual misoprostol show that it is a promising method for medical abortion. Prospective randomized studies are required to compare its efficacy and side effects with vaginal misoprostol and to work out the dosage and dosing interval.

Abortion, Induced↗
PubMed2001

Paracervical block with and without conscious sedation: a comparison of the pain levels during egg collection and the postoperative side effects.

OBJECTIVE: To compare the pain levels during egg collection and the subsequent postoperative side effects in patients receiving a paracervical block (PCB) with and without conscious sedation. DESIGN: A prospective, randomized, double-blind, and placebo-controlled study. SETTING: A tertiary assisted reproduction unit. PATIENT(S): 150 patients undergoing egg collection. INTERVENTION(S): Randomized to receive PCB only (control group) and PCB in conjunction with conscious sedation (sedation group). MAIN OUTCOME MEASURE(S): Vaginal and abdominal pain levels; severity of postoperative side effects. RESULT(S): The median pain levels during vaginal punctures were 12.0 (2.5th--97.5th centiles: 0--84.3) and 30.0 (2.5th--97.5th centiles: 0--100) in the sedation and placebo groups, respectively. The corresponding median abdominal pain levels were 16.5 (2.5th--97.5th centiles: 0--100) and 43.0 (2.5th--97.5th centiles: 0--100). The pain levels were significantly higher in the placebo group than the sedation group. There were no significant differences between the two groups in the severity of nausea, vomiting, dizziness, and drowsiness. CONCLUSION(S): Patients who received only a PCB during the egg collection experienced 2.5 times higher levels of vaginal and abdominal pain as compared to those who received both PCB and conscious sedation. The use of PCB along is not recommended for all patients but it may be considered with selected patients after they have been given extensive counseling.

Abdominal Pain↗
PubMed2001

Ultrasound-guided embryo transfer: a prospective randomized controlled trial.

BACKGROUND: Recent reports suggested that ultrasound guidance during embryo transfer might improve the pregnancy rate. METHODS: A prospective randomized controlled trial was performed to compare embryo transfer under ultrasound guidance versus the clinical touch method. A total of 800 embryo transfers was studied; 400 were randomized to ultrasound-guided transfers and 400 were randomized to the clinical touch group. Of these, 441 were fresh cycles and 359 were frozen-thawed cycles. RESULTS: The clinical pregnancy rate was 26.0% in the ultrasound-guided group and 22.5% in the clinical touch group; the difference was not statistically significant. The ongoing pregnancy rate was 23.5% in the ultrasound-guided group compared with 19.0% in the clinical touch group and the difference was again not statistically significant. The implantation rate was slightly higher in the ultrasound-guided group (15.3%) than the clinical touch group (12.0%) (P = 0.048). There were no differences in the incidences of ectopic pregnancy, miscarriage and multiple pregnancy between the two groups. CONCLUSIONS: A significant improvement in implantation rate was observed following the use of ultrasound guidance during embryo transfer. The extent of improvement in the pregnancy rate may depend on the specific techniques and methods of embryo transfer used in individual centres.

Abortion, Spontaneous↗
PubMed2001

Measurement of serum CA-125 concentrations does not improve the value of Chlamydia trachomatis antibody in predicting tubal pathology at laparoscopy.

Chlamydia antibody testing (CAT) has been used to predict tubal pathology associated with Chlamydia infection, the leading cause of pelvic inflammatory disease (PID). Tubal pathology not related to C. trachomatis is unlikely to be identified by CAT alone. A correlation between serum CA-125 concentrations and the severity of adnexal inflammation during acute PID was demonstrated. The objectives of this study were to determine the prevalence of C. trachomatis infection in an Asian infertile population and to assess the role of a combination of serum CA-125 and CAT in the prediction of tubal pathology as shown by laparoscopy. A total of 110 consecutive women attending an infertility clinic for work-up were recruited. Blood was taken for CAT and CA-125 on the day of hospital admission and an endocervical swab was taken for culture of C. trachomatis prior to laparoscopy. Two (1.8%) women had C. trachomatis found in the endocervix and 28 (25.5%) women had CAT of > or = 1:32. Serum CA-125 concentrations were > 35 IU/ml in 11 (10%) women. The discriminative capacity of CAT in the diagnosis of tubal pathology including both proximal and distal obstruction was not improved by measuring serum CA-125, regardless of the threshold values of serum CA-125 concentration.

Adult↗
PubMed2001

Vaginal misoprostol as medical treatment for first trimester spontaneous miscarriage.

BACKGROUND: Misoprostol is effective for cervical priming prior to suction evacuation in first trimester pregnancy termination. This is the first randomized study to compare vaginal misoprostol versus expectant treatment in women presenting with spontaneous miscarriage. METHODS: Sixty women presenting with spontaneous miscarriage were recruited to the study at the Queen Mary Hospital between 1998 and 1999. They were randomized to group 1: misoprostol; and group 2: expectant management. Women in the misoprostol group received vaginal misoprostol 400 microg on days 1, 3 and 5. The expectant group was followed up according to the same schedule. Suction evacuation was performed if there was excessive bleeding or abdominal pain; or if a gestational sac was detected by transvaginal scan on day 15. RESULTS: Fifty-nine women completed the trial. Those who did not require suction evacuation up to the time of return of normal menstruation were considered to be successful. The incidence of side-effects was comparable between the two groups. Three women in the expectant group and one in the misoprostol group underwent emergency suction evacuation because of excessive bleeding. The mean duration of vaginal bleeding was similar for both groups (14.6 days in the misoprostol group versus 15.0 days in the expectant group). The successful rate in the misoprostol group was significantly higher than that of the expectant group (83.3 versus 48.3%, P < 0.05). CONCLUSION: We recommend repeated vaginal misoprostol 400 microg given on days 1, 3 and 5 as a treatment option for women with first trimester spontaneous miscarriage.

Abortion, Spontaneous↗
PubMed2001

In vitro fertilization and embryo transfer during natural cycles.

OBJECTIVE: To report the results of in vitro fertilization and embryo transfer (IVF/ET) performed during natural cycles. STUDY DESIGN: A prospective clinical study. RESULTS: Thirty-two cycles were started in 19 patients who had regular ovulatory cycles and tubal factors or unexplained infertility only as the cause of infertility. Egg collection was performed in 12 cycles, and four pregnancies resulted from ET in eight cycles. The pregnancy rates were 12.5% per cycle initiated, 33.3% per retrieval cycle and 50% per transfer. CONCLUSION: Natural cycle IVF/ET offers a low-cost alternative to patients with infertility.

Adult↗
PubMed2000

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 Ward's triangle) was substantially less than the projected values (1.1% in lumbar spine, 2.3% in neck of femur, 3.5% in Ward's 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 Ward's 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.

Adult↗
PubMed2000

Comparison of two different doses of lignocaine used in paracervical block during oocyte collection in an IVF programme.

We have recently demonstrated the efficacy of paracervical block (PCB) used in conjunction with conscious sedation during egg collection. The dosage of lignocaine used in various studies ranges from 50 mg to 200 mg. There are, however, no studies evaluating the efficacy of different doses of local anaesthetic agents used in PCB. In this prospective, double-blind and placebo-controlled study, 150 women undergoing egg collection in their first IVF cycle were randomized to receive 200 mg and 150 mg lignocaine in PCB. No differences were seen in the demographic data, the ovarian responses, the duration of egg collection and the number of follicles punctured. The fertilization, implantation and pregnancy rates were similar when either 150 mg or 200 mg lignocaine was employed. The median pain levels during vaginal punctures were 14.0 (2.5th-97.5th centiles: 0-75.4) and 14.0 (2.5th-97.5th centiles: 0-86.5) in patients receiving 200 mg and 150 mg lignocaine respectively, whereas the corresponding median abdominal pain levels were 14.0 (2.5th-97.5th centiles: 0-85.6) and 14.0 (2.5th-97.5th centiles: 0-99.1). These pain levels during egg collection were not significantly different between the two groups. The use of 200 mg lignocaine in PCB is not justified, even in the absence of toxic effects.

Abdominal Pain↗
PubMed2000

Randomized comparison of vaginal (200 microg every 3 h) and oral (400 microg every 3 h) misoprostol when combined with mifepristone in termination of second trimester pregnancy.

It is known that when misoprostol is given at 200 microg every 3 h after mifepristone pretreatment, the vaginal route is more effective than the oral route. However, women prefer the oral route. This randomized study was to test our hypothesis that oral misoprostol 400 microg is as effective as vaginal misoprostol 200 microg when given every 3 h in termination of second trimester pregnancy after priming with mifepristone. A total of 142 patients was randomly assigned to group 1 (200 mg mifepristone + 400 microg oral misoprostol every 3 h up to five doses) or group 2 (200 mg mifepristone + 200 microg vaginal misoprostol every 3 h up to five doses). The incidence of side-effects and the preference study were assessed through a standardized questionnaire during and after the abortion. For the oral group, both the incidence of diarrhoea (40.0 versus 23.2%, P = 0.03) and the amount of drug used (1734 compared with 812 microg, P < 0.0001) were significantly higher than that of the vaginal group but the incidence of fever appeared to be lower (not significant). There was no significant difference in complete abortion rate: 81.4% in the oral group and 75.4% in the vaginal group. The median induction-abortion interval was similar in the two groups (10.4 versus 10.0 h). The percentage of women who aborted in 24 h was also similar: 57/70 (81.4%) in the oral group and 58/69 (87.0%) in the vaginal group. Overall, 82.0% of women preferred the oral route. Oral misoprostol (400 microg) given every 3 h up to five doses, when combined with mifepristone, was as effective as the vaginal (200 microg) route in second trimester termination of pregnancy. This regimen could also be offered to those women who found repeated vaginal administration unacceptable.

Abortifacient Agents, Nonsteroidal↗
PubMed2000

Vaginal misoprostol alone for medical abortion up to 9 weeks of gestation: efficacy and acceptability.

Misoprostol and mifepristone have been shown to be effective for medical abortion up to 9 weeks of gestation. When used alone, the successful complete abortion rate dropped to approximately 60%. It has been demonstrated that by adding water to misoprostol, the success rate rose to 92%. This is the first randomized study to investigate the efficacy of misoprostol and water versus misoprostol alone for first trimester medical abortion in women at </= 9 weeks of gestation. Eighty women were randomly assigned to group 1 (water added to misoprostol) and group 2 (misoprostol alone). Vaginal misoprostol 800 microgram was given on days 1, 3 and 5. If the woman did not require vacuum aspiration during the period up to the return of first menstruation after medical abortion, the outcome was classified as complete abortion. The incidence of side-effects and the acceptability were assessed through a standardized questionnaire during and after the abortion. The complete abortion rate appeared higher when water was added but the difference did not reach statistical significance. Gastro-intestinal side-effects were common but well tolerated in both groups. Overall, 40% of the women preferred a surgical method in the future because of the high failure rate. With an overall complete abortion rate of 85%, it is probably not a clinically acceptable method even if the addition of water can improve the results. We conclude that the addition of water onto misoprostol tablets does not improve its efficacy in first trimester medical abortion. Misoprostol alone is not recommended for medical abortion (up to 9 weeks of pregnancy) because of the high failure rate and low acceptability.

Abortifacient Agents, Nonsteroidal↗
PubMed2000

Cortical vein thrombosis misinterpreted as intracranial haemorrhage in severe ovarian hyperstimulation syndrome: case report.

A case of cortical vein thrombosis presenting as intracranial haemorrhage is described in a patient with ovarian hyperstimulation syndrome (OHSS) after IVF and embryo transfer. Veno-occlusive disease of the brain could appear as a haemorrhagic lesion on magnetic resonance imaging (MRI) and this made the initial diagnosis of cortical vein thrombosis difficult. The patient developed deep vein thrombosis 2 weeks after the intracranial event and the diagnosis of cortical vein thrombosis was made at that time on MRI study after the resolution of the haemorrhage. This patient actually developed generalized thrombosis as a complication to OHSS. Although the initial MRI picture may be misleading, the diagnosis of thrombosis should always be kept in mind, as it is the commonest cause of intracranial lesions after OHSS.

Adult↗
PubMed2000

The significance of the number of antral follicles prior to stimulation in predicting ovarian responses in an IVF programme.

Multiple follicular development plays a major role in the successful outcome of IVF and embryo transfer treatment. Prediction of ovarian responses prior to stimulation is useful in counselling patients and helpful in tailoring the dosage of gonadotrophin to individual patients. The objective of this study was to compare age of women, body mass index (BMI), basal FSH concentration, volume of both ovaries and the number of antral follicles of both ovaries in predicting the number of oocytes obtained. A total of 128 consecutive women, who had no history of ovarian surgery, were non-smokers and undergoing the first cycle using a standard regimen of ovarian stimulation were examined. The total number of antral follicles achieved the best predictive value, followed by basal FSH, BMI and age of women. In those women with fewer antral follicles, a longer duration and higher dosage of human menopausal gonadotrophin were required but the number of eggs obtained was significantly less than for those with more antral follicles. Significantly more cycles were cancelled before egg collection in women with < or =6 antral follicles while more cycles of embryo transfer were postponed in order to reduce the risk of ovarian hyperstimulation syndrome in women with >9 antral follicles.

Adult↗
PubMed1999

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 Ward's 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 Ward's 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.

Absorptiometry, Photon↗