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Biomedical subjects

Pak Chung Ho

Publications and source records attributed to Pak Chung Ho.

At least 55 records · Page 3Linked to original sources
PubMed2003

Prostaglandins for induction of second-trimester termination and intrauterine death.

The introduction of synthetic prostaglandin has revolutionized the treatment protocol for induction of second-trimester abortion and intrauterine death. Gemeprost is the only licensed synthetic prostaglandin analogue for second-trimester abortion in the United Kingdom. However, it is expensive and needs to be stored in a refrigerator. Misoprostol is marketed for use in the prevention and treatment of peptic ulcer. It is inexpensive and can be stored at room temperature. It has been widely used for induction of second-trimester abortion and intrauterine death. Misoprostol, 400 microg given vaginally every 3hours, is probably the optimal regimen for second-trimester abortion. The combination of misoprostol and mifepristone significantly reduced the induction-to-abortion interval when compared with the misoprostol-only regimen. In addition, misoprostol can also be used as a cervical priming agent prior to dilatation and evacuation in second-trimester abortion.

Abortifacient Agents, Nonsteroidal↗
PubMed2003

A randomized double-blind study to compare the effectiveness of three different doses of lignocaine used in paracervical block during oocyte retrieval.

PURPOSE: To compare the effectiveness of three different doses of lignocaine used in paracervical block (PCB) during transvaginal ultrasound-guided oocyte retrieval (TUGOR) METHODS: In this double-blind study, 153 patients undergoing TUGOR in their first in vitro fertilization cycle were randomized to receive 50, 100, and 150 mg of lignocaine in PCB. Pain levels were measured by a 100-mm linear visual analogue scale (0 = none to 100 = intolerable). RESULTS: No differences were seen in the demographic data, the ovarian responses, the duration of TUGOR, and the number of follicles punctured. Vaginal and abdominal pain levels during TUGOR and 4 h after TUGOR were not significantly different among the three groups The median vaginal and abdominal pain levels during the retrieval were 22.0-24.0 and 30.0-32.0 respectively. CONCLUSION: The use of 50 mg of lignocaine is recommended in PCB because of the lack of improvement in pain relief on higher doses and potential dose-related risks.

Abdominal Pain↗
PubMed2003

Oocyte and embryo quality in patients with excessive ovarian response during in vitro fertilization treatment.

PURPOSE: This study examined oocyte and embryo quality in patients having excessive ovarian responses during assisted reproduction treatment. METHODS: Two hundred and seventy-eight women of age <40 years using a long protocol of pituitary downregulation in their first intracytoplasmic sperm injection cycle indicated for severe male factors were retrospectively evaluated. Those with serum estradiol concentration on the day of HCG <10,000, 10,000-20,000, and >20,000 pmol/L were classified into Group A, Group B, and Group C, respectively. RESULTS: The percentage of metaphase II oocytes (85%), fertilization rate (60-66%), and distribution of blastomere number per embryo were similar among the three groups. The proportion of transferable embryos was not reduced in Group C when compared to those of Groups A and B. CONCLUSION: Excessive ovarian response does not compromise oocyte and embryo quality in humans. Freezing of all embryos is recommended in these patients in view of associated impaired endometrial receptivity.

Adult↗
PubMed2003

A prospective randomized study to compare the use of repeated doses of vaginal with sublingual misoprostol in the management of first trimester silent miscarriages.

BACKGROUND: A randomized controlled trial comparing sublingual with vaginal administration of misoprostol for medical management of silent miscarriages. METHODS: Eighty women who had silent miscarriages (<13 weeks) were randomized to receive 600 micro g of misoprostol every 3 h for a maximum of three doses either sublingually or vaginally. RESULTS: The success rates of medical management were the same in both groups (87.5%; 95% CI: 74-95%). There were no serious complications. The incidence of diarrhoea was higher in the sublingual (70%) than the vaginal route (27.5%) (P < 0.005). Other side effects were similar in each group, although fatigue was experienced by more women in the sublingual group than in the vaginal group (65 versus 40%: P = 0.043). The overall acceptability of medical management was good. Most women would choose the medical method if they were allowed to choose again and would recommend the method to others. CONCLUSION: The current regimen of misoprostol is useful for the management of silent miscarriage in terms of complete miscarriage rate and patient acceptability. Sublingual misoprostol may offer an alternative for women who do not like repeated vaginal administration of the drug.

Abortifacient Agents, Nonsteroidal↗
PubMed2003

The significance of the ionophore-challenged acrosome reaction in the prediction of successful outcome of controlled ovarian stimulation and intrauterine insemination.

BACKGROUND: This prospective study compared the acrosome reaction following ionophore challenge (ARIC) versus conventional sperm parameters and sperm velocities in predicting successful outcome following ovarian stimulation and intrauterine insemination. METHODS: All patients were offered a maximum of three treatment cycles. Conventional semen analysis was performed and sperm velocities were measured using computer-aided sperm analysis. Acrosome-reacted sperm were stained using chlortetracycline after ionophore challenge. Multiple logistic regression analysis and the receiver-operator characteristic curve analysis were applied to determine the best predictive variables and their cut-off values. RESULTS: ARIC score was the most significant variable in predicting pregnancy, followed by the percentage of induced acrosome-reacted sperm, serum estradiol levels on the day of hCG and sperm morphology by strict criteria. Higher spontaneous acrosome reaction had a negative relationship with pregnancy. ARIC score of 10% had a sensitivity of 85.3% and a specificity of 85.5%. The positive and negative predictive values were 64.2 and 96.6% respectively and the false positive and negative rates were 14.7 and 14.5% respectively. CONCLUSION: ARIC score was a better predictor of pregnancy than conventional sperm parameters and sperm velocities.

Acrosome Reaction↗
PubMed2003

Effects of age on hormonal and ultrasound markers of ovarian reserve in Chinese women with proven fertility.

BACKGROUND: A woman's fertility is remarkably reduced with increasing age. Reproductive age can be assessed by a number of ovarian reserve tests. There are very few studies addressing the effects of age on these markers in fertile women, especially in Asia. METHODS: On the second to fourth day of the menstrual period, fertile Chinese women with regular monthly cycles and no history of ovarian surgery underwent a transvaginal scan with colour Doppler to determine ovarian volume, total antral follicle count (AFC) and mean peak systolic velocity (PSV) of ovarian stromal blood flow, and their serum FSH and inhibin B levels were checked. RESULTS: Out of 145 women scanned, 119 were included in the final analysis. AFC is the only ovarian reserve marker that was significantly different among four age groups (</=20, 21-30, 31-40 and >40 years). AFC had the best correlation with the age of the women, followed by FSH level and ovarian volume. The decline of AFC with age was 3.8% per year (95% confidence interval 2.7-4.9%) in the conventional linear regression model, which was not improved by the biphasic linear regression model. CONCLUSION: Of the parameters tested, AFC showed the best correlation with women's age and declined linearly at a rate of 3.8% per year.

Adolescent↗
PubMed2003

A prospective, randomized, placebo-controlled trial on the use of mifepristone with sublingual or vaginal misoprostol for medical abortions of less than 9 weeks gestation.

BACKGROUND: A combination of mifepristone and misoprostol provides an effective method of medical abortion for early pregnancy. This is the first randomized trial comparing the use of sublingual misoprostol with vaginal misoprostol in combination with mifepristone for termination of early pregnancies up to 63 days. METHODS: A total of 224 women who requested legal termination of pregnancy up to 63 days were randomized by computer- generated list into two groups and given 200 mg of oral mifepristone followed 48 h later by either 800 micro g of sublingual (n = 112) or vaginal (n = 112) misoprostol. RESULTS: Complete abortion occurred in 98.2% (95% CI: 93-99) of women in the sublingual group and 93.8% (95% CI: 88-97) in the vaginal group. There were three ongoing pregnancies in the vaginal group but none in the sublingual group. The median duration of vaginal bleeding was 17 days. There was no serious complication. Fever, chills and gastrointestinal side-effects (nausea, vomiting and diarrhoea) were significantly more common in the sublingual group. CONCLUSIONS: The combination of mifepristone and misoprostol is effective for medical abortion up to 63 days. Both the sublingual and vaginal are effective routes of administration. Further randomized trials are required to find out the optimal dose of sublingual misoprostol that can give the highest complete abortion rate and lowest incidence of side-effects.

Abortifacient Agents, Nonsteroidal↗
PubMed2003

The effect of mifepristone on the expression of steroid hormone receptors in human decidua and placenta: a randomized placebo-controlled double-blind study.

The objective of this study was to investigate the expression of steroid hormone receptors in human first trimester placenta and decidua and whether such expression was altered after mifepristone treatment. One hundred women who requested termination of pregnancy between 7 and 12 wk were randomly assigned to receive placebo or 200 mg mifepristone at 12, 24, and 48 h before suction evacuation of uterus. Immunohistochemistry was used to detect the expression of progesterone receptor, estrogen receptor, glucocorticoid receptor (GR), and androgen receptor. Progesterone receptor expression in both placenta and decidua tissues was not affected by mifepristone treatment. Estrogen receptor was identified in a decidual gland in only one sample. Androgen receptor was not expressed in either tissue. The expression of GR in decidual stromal cells was suppressed by mifepristone, and the effect was detectable at 12 h after administration. The expression of GR in decidual glands was not affected. In the placenta, the expression of GR in cytotrophoblasts and villous stromal cells was suppressed by mifepristone; the effect was detectable at 12 h and persisted at 48 h. In conclusion, the suppressed GR expression after mifepristone administration may be part of the mechanism of mifepristone in causing abortion.

Abortifacient Agents, Steroidal↗
PubMed2003

A randomized comparison of three insemination methods in an artificial insemination program using husbands' semen.

OBJECTIVE: To compare pregnancy rates with single intrauterine insemination (SIUI), double intrauterine insemination (DIUI) and fallopian tube sperm perfusion (FSP). STUDY DESIGN: Ninety patients undergoing a standard ovarian stimulation regimen were randomized to receive SIUI, DIUI or FSP. The end point was either pregnancy or completion of 3 treatment cycles without pregnancy. RESULTS: There were no differences in demographic data or ovarian responses. The total number of motile spermatozoa inseminated in the FSP group was significantly lower than in the SIUI group. No significant differences were found in pregnancy rate per cycle or patient, multiple pregnancy rate and outcome of pregnancy between the 3 groups. CONCLUSION: Similar pregnancy rates were achieved after SIUI, DIUI and FSP during stimulated cycles.

Adult↗
PubMed2002

Attitude of at-risk subjects towards preimplantation genetic diagnosis of alpha- and beta-thalassaemias in Hong Kong.

OBJECTIVES: The aim of the study was to assess whether preimplantation genetic diagnosis (PGD) was an acceptable alternative to prenatal diagnosis in couples at risk of giving birth to a child with alpha- or beta-thalassaemia in an Asian population. METHODS: An information leaflet was distributed to the women at risk. They were asked to complete a questionnaire after having an interview with a designated investigator. RESULTS: A total of 141 valid questionnaires were analysed; 82.3% of the women considered PGD either the same or better than conventional prenatal diagnosis. Women with an affected child or a subfertility problem were more willing to accept PGD and to undergo this procedure in their future pregnancies. Their main concern about PGD was damage to the embryo during the PGD procedure. The most important perceived advantage of PGD was avoidance of termination of an affected pregnancy. CONCLUSIONS: PGD is an acceptable alternative to conventional prenatal diagnosis in women at risk of giving birth to a child with alpha- or beta-thalassaemia in an Asian population. This is particularly true in women with a subfertility problem and in women who already have an affected child.

Adult↗
PubMed2002

Cycle-to-cycle variation in utero-ovarian hemodynamic indices in ovarian stimulation and natural cycles of the same women and its effect on the outcome of assisted reproduction treatment.

OBJECTIVE: To investigate the blood flow parameters between cycles of the same women to assess whether parameters predicting a successful pregnancy in a stimulation cycle could be used to determine the outcome of subsequent natural cycles. DESIGN: A prospective study. SETTING: Assisted reproduction unit, the University of Hong Kong. PATIENT(S): Fifty-eight IVF cycles and 40 natural cycles were evaluated. INTERVENTION(S): Assessments of the utero-ovarian pulsatility indices (PIs), resistance indices (RIs), and endometrial color signals. RESULT(S): In IVF cycles, the pregnancy rate (27%) was similar to that in frozen-thawed embryo transfer (FET) (28%) cycles. The utero-ovarian PIs and RIs in IVF cycles were significantly lower than those in the natural cycles. There was a significant correlation between the uterine PI in stimulation cycles and that in natural cycles. In IVF cycles, the pregnancy rate declined significantly when the uterine PI was >2.70 and the RI was >0.9. In FET cycles, no decline in pregnancy rate was seen. Conceptional FET cycles showed significantly higher uterine PI, uterine RI, and endometrial color signals compared with conceptional IVF cycles. CONCLUSION(S): Hemodynamic parameters in stimulation cycles are different from those in natural cycles, and the values of various parameters in predicting pregnancy are also different.

Cryopreservation↗
PubMed2002

Medical abortion in the second trimester.

The introduction of prostaglandin analogues and mifepristone has changed the management of second trimester abortion in the last 2 decades. Gemeprost and misoprostol are the two most extensively studied prostaglandin analogues that are used in this period. The combination of either gemeprost or misoprostol with mifepristone is most effective. With these regimens, over 90% of women abort within 24 hours and the mean induction to abortion interval is about 6 hours. Mifepristone is expensive and is not available in many countries. Therefore, prostaglandin analogue-only regimens might be the only option. These regimens are still effective with an abortion rate of >90% in 48 hours. However, the induction to abortion interval (15 hours) is much longer. Intra-cervical tents can be used to shorten the induction to abortion intervals.

Abortifacient Agents↗
PubMed2002

The effect of contraceptive pills on the measured blood loss in medical termination of pregnancy by mifepristone and misoprostol: a randomized placebo controlled trial.

BACKGROUND: A prospective randomized placebo controlled trial was performed to assess the immediate use of oral contraceptive (OC) on the amount of blood loss in the post-abortion period in women undergoing medical abortion by mifepristone and misoprostol. METHODS: One hundred women were randomized by computer to receive either OC pills or placebo, immediately after medical abortion. RESULTS: There was no difference in the complete abortion rate between the two groups. The complete abortion rate was 98 and 92% in the OC and placebo groups respectively. The side-effects and duration of bleeding were also similar. The median days of vaginal bleeding were 17 (range: 3-41) and 15 (range: 5-48) in the OC and placebo groups respectively. There was a statistically significant decrease in the mean haemoglobin level on day 15 in the OC group (from 12.0 to 11.5 g/dl) whereas the mean haemoglobin level in the placebo group remained stable. The median measured blood loss was 69.9 ml in the OC group and 72.8 ml in the placebo group and there was no statistically significant difference between the two groups. CONCLUSION: We conclude that it is safe to offer women combined OC pills immediately after medical abortion as an option of contraception, as it does not affect the duration or amount of vaginal bleeding or the complete abortion rate.

Abortifacient Agents↗
PubMed2002

A prospective randomized study on the measured blood loss in medical termination of early pregnancy by three different misoprostol regimens after pretreatment with mifepristone.

BACKGROUND: Prolonged vaginal bleeding is a common complaint after medical abortion. The effect of a 1 week course of daily oral misoprostol after medical abortion with mifepristone and misoprostol on the amount of post-abortal blood loss was studied. METHODS: A total of 150 women (gestation <or=63 days) were randomized to three groups using computer-generated tables. They received 200 mg oral mifepristone, followed 48 h later by 0.8 mg oral misoprostol and vaginal placebo in group A, and 0.8 mg vaginal misoprostol and oral placebo in groups B and C. In groups A and B, the women continued with oral misoprostol 0.4 mg twice daily on days 4-10, while the women in group C took placebo. The actual blood loss was measured by the alkaline haematin method. RESULTS: No significant difference in the median amount (82.8, 94.7 and 88.5 ml for A, B and C respectively) and duration (16, 15 and 16 days respectively) of vaginal bleeding was observed. The incidence of diarrhoea was significantly higher (66, 55.1 and 12.5% respectively) in the groups with oral misoprostol after abortion. CONCLUSION: A 1 week course of oral misoprostol (0.4 mg twice daily) could not decrease the duration and amount of vaginal bleeding. Further studies with a larger sample size are needed to assess whether the complete abortion rate can be improved with this regimen.

Abortifacient Agents, Steroidal↗
PubMed2002

A randomized double-blind comparison of perifollicular vascularity and endometrial receptivity in ovulatory women taking clomiphene citrate at two different times.

BACKGROUND: It is still controversial whether the day of clomiphene citrate initiation has any impact on the pregnancy rate. This study aimed to compare the perifollicular vascularity and endometrial receptivity of ovulatory women who started clomiphene citrate on day 2 and day 5. METHODS: Thirty-five women with regular ovulatory cycles were first monitored in a natural cycle and then randomized by computer-generated random numbers put in sealed opaque envelopes to receive 50 mg clomiphene citrate on days 2-6 or on days 5-9. The hormonal profile, the number of dominant follicles, the grading of perifollicular vascularity, endometrial thickness and Doppler flow indices of uterine/subendometrial arteries were compared between both groups. RESULTS: All the above parameters were similar for both groups on the day of the LH surge and 7 days after the LH surge. CONCLUSIONS: There were no differences in oocyte quality graded by the perifollicular vascularity and the endometrial receptivity assessed by endometrial thickness and Doppler flow indices of uterine and subendometrial vessels when clomiphene citrate was started in regularly ovulatory women on day 2 or on day 5.

Adult↗
PubMed2002

Pharmacokinetics of different routes of administration of misoprostol.

BACKGROUND: The pharmacokinetic parameters of four different routes of administration of a single dose of 400 microg of misoprostol were studied. METHODS: A total of 40 women undergoing termination of pregnancy by suction evacuation was randomized by computer model to receive 400 microg of misoprostol by one of four routes: (i) sublingual (ii) oral (iii) vaginal and (iv) vaginal with addition of water. Venous blood samples were taken at 0, 1, 2, 5, 10, 20, 30, 45, 60, 120, 240 and 360 min after the administration of misoprostol. Misoprostol acid (MPA) was determined in serum samples using gas chromatography/tandem mass spectrometry. RESULTS: Sublingual misoprostol achieved the highest serum peak concentration (Cmax) (574.8 +/- 250.7 pg/ml) of MPA and this was significantly higher than those in the other groups [Oral: 287.6 +/- 144.3 pg/ml (P < 0.01), vaginal: 125.2 +/- 53.8 pg/ml (P < 0.001) and vaginal with water: 162.8 +/- 57.1 pg/ml (P < 0.001)]. The time to peak concentration (Tmax) was similar in both the sublingual (26.0 +/- 11.5 min) and oral groups (27.5 +/- 14.8 min) and was significantly shorter than those in both vaginal groups. The area under the MPA concentration versus time curve up to 360 min in the sublingual group (743.7 +/- 291.2 pg.h/ml) was significantly greater than those in oral (402.8 +/- 151.6 pg.h/ml, P < 0.05) and vaginal (433.7 +/- 182.6 pg.h/ml, P < 0.05) groups, but no significant difference was found between sublingual and vaginal administration if water (649.3 +/- 333.8 pg.h/ml) was added. CONCLUSION: The new sublingual route of administration of misoprostol demonstrated a great potential to be developed into a method of medical abortion.

Abortifacient Agents, Nonsteroidal↗
PubMed2002

Pilot study on the use of repeated doses of sublingual misoprostol in termination of pregnancy up to 12 weeks gestation: efficacy and acceptability.

BACKGROUND: A sublingual misoprostol-alone regimen was used in 50 women requesting medical abortion at up to 12 weeks gestation. The efficacy and acceptability of this regimen were studied. METHODS: The women were given 600 microg misoprostol sublingually every 3 h for a maximum of 5 doses. RESULTS: The overall complete abortion rate was 86% (95% confidence interval: 74-93). The mean number of doses of misoprostol required was 4.1 +/- 1.1. There was no significant change in haemoglobin concentration and the median duration of vaginal bleeding was 15 days (range: 7-56). Diarrhoea, fever and chills were the most common side-effects. The acceptability of this regimen of misoprostol was good: 97.7% of the women who had a complete abortion would choose this method again and 88.4% would recommend it to others. They preferred sublingual misoprostol as it is convenient to take, avoids the painful vaginal administration and gives more privacy during the abortion process. CONCLUSION: This regimen of sublingual misoprostol is an effective and acceptable method of medical abortion. Randomized controlled trials are required to compare the efficacy of various misoprostol-alone regimens of medical abortion. Pharmacokinetic studies and clinical trials are needed to find out the most appropriate dose, dosing interval and route of administration of misoprostol.

Abortifacient Agents, Nonsteroidal↗