Biomedical subjects

Pak Chung Ho

Publications and source records attributed to Pak Chung Ho.

At least 37 records · Page 2Linked to original sources

PubMed2005

Comparison of ovarian stromal blood flow between fertile women with normal ovaries and infertile women with polycystic ovary syndrome.

BACKGROUND: Conflicting information exists in the literature with respect to ovarian stromal blood flow in women with polycystic ovary syndrome (PCOS). We compared the ovarian stromal blood flow and serum vascular endothelial growth factor (VEGF) concentration between fertile women with normal ovaries and infertile women with PCOS. METHODS: In the second to fourth day of the menstrual period, they underwent transvaginal scanning with three-dimensional (3D) power Doppler to determine total antral follicle count (AFC), total ovarian volume, total ovarian vascularization index (VI), flow index (VFI) and vascularization flow index (VFI). Serum FSH, LH and VEGF concentrations were also checked. RESULTS: 107 fertile controls and 32 PCOS women were recruited. Fertile controls and PCOS women had similar total ovarian VI/FI/VFI after controlling for age of the woman, although PCOS women had significantly higher total AFC, total ovarian volume and serum LH concentration than fertile controls. Total ovarian VI/FI/VFI were significantly higher in normal weight (BMI < 25 kg/m2) PCOS women than their overweight (> or = 25 kg/m2) counterparts. CONCLUSIONS: Fertile controls and PCOS women had similar total ovarian 3D power Doppler flow indices. Normal weight PCOS women had significantly higher total ovarian 3D power Doppler flow indices than their overweight counterparts.

Adult↗

PubMed2005

Antral follicle count and FSH concentration after clomiphene citrate challenge test in the prediction of ovarian response during IVF treatment.

BACKGROUND: We compared: (i) antral follicle count (AFC) in the early follicular phase, after the clomiphene citrate challenge test (CCCT) and before ovarian stimulation following pituitary down-regulation; and (ii) age of women, body mass index, basal and stimulated serum FSH concentrations and AFC in predicting the ovarian response of infertile women aged <40 years with basal FSH <10 IU/l on recruitment in their first IVF cycle. METHODS: Two months prior to the treatment cycle, AFC and basal FSH concentration were determined on day 2-3 of a spontaneous period and on day 10 after CCCT. All women received a standard stimulation regimen. Ovarian response was represented by the number of oocytes, serum estradiol, the duration and dosage of gonadotrophins. RESULTS: There was no significant difference between basal, stimulated and down-regulated AFC. AFC achieved the best predictive value in relation to the number of oocytes, followed by combined FSH concentration (sum of the two FSH concentrations) and age of women. Both basal AFC and combined FSH concentration were predictive factors of serum estradiol concentration, whereas stimulated FSH concentration was predictive of the total dosage of gonadotrophins. CONCLUSION: Combined FSH concentration after CCCT provides additional information in predicting ovarian response.

Adult↗

PubMed2005

A randomized double-blind controlled study of the efficacy of laser-assisted hatching on implantation and pregnancy rates of frozen-thawed embryo transfer at the cleavage stage.

BACKGROUND: Assisted hatching (AH) in fresh embryo transfer (ET) cycles increases the implantation and pregnancy rates, especially in women with a poor prognosis, repeated implantation failures and in older women. Little information exists in the literature regarding the role of AH in frozen-thawed embryo transfer (FET) cycles. METHODS: Embryos were cryopreserved at the cleavage stage. On the day of FET, 160 patients were randomized according to a computer-generated randomization list in sealed envelopes into the AH group and the control group. The patients and the clinicians were blinded to the group assigned. In the AH group, the outer half of the zona pellucida over a quarter of the diameter of zona was removed using a 1480 nm non-contact laser. RESULTS: The two groups were comparable in terms of demographic characteristics, ovarian response of the stimulated cycle and quality of fresh and frozen-thawed embryos. No differences in implantation, pregnancy and multiple pregnancy rates were found between the two groups. There was a non-significant trend of a higher implantation rate in the AH group when the zona thickness was > or = 16 mm. CONCLUSION: Laser AH did not improve the implantation rate of FET cycles and should not be performed routinely in all frozen-thawed embryos at the cleavage stage.

Adult↗

PubMed2005

Maternal serum pregnancy-associated plasma protein-A and free beta-human chorionic gonadotrophin in pregnancies conceived with fresh and frozen-thawed embryos from in vitro fertilization and intracytoplasmic sperm injection.

OBJECTIVE: Maternal serum pregnancy-associated plasma protein-A (PAPP-A) and free beta-human chorionic gonadotrophin (beta-hCG) are useful markers in the screening of Down syndrome in the first trimester. We investigated the effect of intracytoplasmic sperm injection (ICSI), freezing and thawing of embryos on the levels of these two analytes in assisted reproduction pregnancies. METHODS: We recruited 149 women who conceived after assisted reproduction with fresh embryos (92 from conventional IVF and 57 from ICSI), 85 women who conceived with frozen-thawed embryos (54 from conventional IVF and 31 from ICSI) and 401 women with spontaneous conceptions as controls. The concentrations of PAPP-A and free beta-hCG were measured between 10 and 14 weeks and were converted to multiples of medians (MoM) for comparisons. RESULTS: Median PAPP-A MoMs were significantly reduced in ICSI pregnancies in the fresh and frozen-thawed embryo subgroups (0.70 and 0.66 MoM respectively) and in the IVF fresh embryo subgroups (0.83 MoM), as compared to controls (1.00 MoM). Free beta-hCG MoM was significantly reduced in the IVF fresh embryos subgroup (0.87 MoM), but not in the other three subgroups. CONCLUSION: Further studies for exploring the underlying pathophysiology and adjustment in the marker levels for screening of Down syndrome are warranted in pregnancies conceived after assisted reproduction.

Adult↗

PubMed2005

The significance of antral follicle count in controlled ovarian stimulation and intrauterine insemination.

PURPOSE: This retrospective study evaluated the role of antral follicle count (AFC) in predicting ovarian response and successful outcome of stimulated insemination cycles. METHODS: One-hundred and fifty infertile women with bilateral patent tubes receiving a standard regime of human menopausal gonadotrophin (HMG) in their first cycle were evaluated. Multiple regression analysis was used to evaluate the effects of different parameters on ovarian responses and multiple logistic regression analysis was applied to determine which parameters gave the maximum discrimination to predict clinical pregnancy. RESULTS: Body mass index was the only significant parameter to predict the number of follicles > or =14 mm whereas AFC was the only significant parameter to predict the HMG duration. Only the number of follicles > or =14 mm significantly improved the chance of clinical pregnancy with an odds ratio of 1.8. CONCLUSION: AFC was related to the HMG duration but was not predictive of number of follicles and clinical pregnancy of stimulated insemination cycles.

Adult↗

PubMed2004

Endometrial and subendometrial blood flow measured by three-dimensional power Doppler ultrasound in patients with small intramural uterine fibroids during IVF treatment.

BACKGROUND: The impact of intramural fibroids on the success of IVF treatment is controversial and the mechanisms leading to poor treatment outcomes remain unknown. We compared endometrial and subendometrial blood flow between women with and without intramural fibroids during IVF treatment. METHODS: Three-dimensional (3D) ultrasound examination with power Doppler was performed on the day of oocyte retrieval in 50 patients with intramural fibroids not distorting the uterine cavity and in 50 matched controls to measure endometrial thickness, uterine pulsatility index (PI)/resistance index (RI), endometrial volume and vascularization index (VI)/flow index (FI)/vascularization flow index (VFI) of endometrial and subendometrial regions. Smokers, patients with serum estradiol concentrations > or =20,000 pmol/l on the day of HCG and previous history of myomectomy were excluded. RESULTS: Endometrial thickness and pattern, averaged uterine PI and RI and endometrial and subendometrial VI/FI/VFI were similar between the fibroid group and the control group. There was no correlation between the total volume of fibroids and endometrial and subendometrial 3D power Doppler flow indices in the fibroid group. CONCLUSION: Endometrial and subendometrial 3D power Doppler flow indices were similar in patients with and without small intramural fibroids.

Adult↗

PubMed2004

A randomized trial to compare 24 h versus 12 h double dose regimen of levonorgestrel for emergency contraception.

BACKGROUND: Levonorgestrel (0.75 mg given for two doses 12 h apart) has been proven to be an effective regimen for emergency contraception when the first dose is given within 72 h of unprotected coitus. However, the dosing interval is inconvenient for those taking the first dose in the afternoon. We conducted a randomized study to evaluate two levonorgestrel dosing regimens for emergency contraception. Two doses of levonorgestrel 0.75 mg were administered with the first dose given up to 120 h after unprotected intercourse. The second dose was given 12 h later in the first regimen and 24 h later in the second regimen. METHODS: We conducted a double-blind, randomized trial between 1997 and 2003 at five centres in China. A total of 2071 women requesting emergency contraception within 120 h of unprotected intercourse were recruited. They were randomized to receive two doses of 0.75 mg of levonorgestrel, given either 24 h apart or 12 h apart. RESULTS: Outcome was unknown for 53 women (24 in the 24 h group and 29 in the 12 h group). Among the remaining 2018 women, the crude pregnancy rate was 1.9% in the 24 h group [95% confidence interval (CI) 1.17-2.94] and 2.0% in the 12 h group (95% CI 1.19-2.99). The proportion of pregnancies prevented was estimated to be 72% in the 24 h group and 75% in the 12 h group. Side-effects were mild in both groups. The efficacy of the 12 h regimen declined significantly when there were further acts of intercourse after treatment (5.0 versus 1.0%, P<0.01). This was not observed in the 24 h group. CONCLUSIONS: Two doses of 0.75 mg levonorgestrel given either 24 or 12 h apart are effective for emergency contraception up to 120 h after unprotected intercourse. Further research to investigative more effective methods of emergency contraception is warranted.

Adult↗

PubMed2004

Effect of pituitary downregulation on antral follicle count, ovarian volume and stromal blood flow measured by three-dimensional ultrasound with power Doppler prior to ovarian stimulation.

BACKGROUND: Despite the extensive use of gonadotrophin releasing hormone agonists (GnRH ag) for pituitary downregulation, the literature regarding their effect on ultrasound parameters for predicting ovarian responses are few and conflicting. The aim of this prospective study was to compare antral follicle count (AFC), ovarian volume and ovarian stromal blood flow measured by three-dimensional (3D) power Doppler ultrasound before and after pituitary downregulation. METHODS: All patients received a long protocol of intranasal Buserelin from the mid-luteal phase of the cycle. In the early follicular phase of the preceding cycle before downregulation and on the second day of the treatment cycle after downregulation, patients underwent a blood test for serum FSH, LH and estradiol and a transvaginal scanning with 3D power Doppler to determine AFC, ovarian volume and ovarian 3D power Doppler flow indices. RESULTS: Out of 104 women scanned, 85 women were analysed. Polycystic ovaries were encountered in 14 (16.5%) women. No significant differences in any of the ultrasound parameters were demonstrated before and after downregulation, in patients with normal ovaries or in those with polycystic ovaries. CONCLUSION: AFC, ovarian volume and ovarian 3D power Doppler flow indices did not significantly change after a short-term treatment of GnRH agonist for pituitary downregulation.

Adult↗

PubMed2004

Comparison of endometrial and subendometrial blood flow measured by three-dimensional power Doppler ultrasound between stimulated and natural cycles in the same patients.

BACKGROUND: Low implantation rates in stimulated IVF cycles may be related to suboptimal endometrial perfusion. Endometrial and subendometrial blood flow was compared between stimulated and natural cycles in the same patients undergoing IVF. METHODS: Three-dimensional (3D) ultrasound examination with power Doppler was performed in stimulated and natural cycles of 67 consecutive patients to measure endometrial thickness, uterine artery pulsatility index/resistance index, endometrial volume, vascularization index (VI)/flow index (FI)/vascularization flow index (VFI) of endometrial and subendometrial regions. RESULTS: Endometrial and subendometrial blood flow was absent in four (6.0%) patients in the stimulated cycle and two (3.0%) patients in the natural cycle. Endometrial and subendometrial VI/FI/VFI were significantly lower in stimulated cycles than those in natural cycles. The median (95% CI) decreases in endometrial VI/FI/VFI were 35.8% (-2.5, 216.8), 5.0% (0.1, 12.3) and 48.4% (2.5, 315.3) respectively whereas the corresponding decreases in the subendometrial region were 66.6% (-0.2, 220.5), 4.3% (0.8, 16.2) and 76.3% (41.0, 303.4) respectively. CONCLUSION: Endometrial and subendometrial blood flow was significantly lower in the stimulated cycle than that in the natural cycle.

Adult↗

PubMed2004

Effect of age on ovarian stromal flow measured by three-dimensional ultrasound with power Doppler in Chinese women with proven fertility.

BACKGROUND: Increasing age is associated with reduced ovarian stromal blood flow detected by three-dimensional (3D) power Doppler ultrasound in infertile patients. However, little information exists in the literature regarding the effect of age on the ovarian stromal blood flow in fertile women. METHODS: On the second to fourth day of their menstrual cycle, fertile Chinese women who had regular monthly cycles and no history of tubal and ovarian surgery underwent a transvaginal scan with 3D power Doppler to determine total antral follicle count (AFC), total ovarian volume, total ovarian vascularization index (VI)/flow index (FI)/vascularization flow index (VFI). Serum FSH and vascular endothelial growth factor concentrations were checked. RESULTS: Out of 177 women scanned, 138 women were included in the final analysis. Total AFC and serum FSH were significantly different among four age groups (< or = 30, 31-35, 36-40 and > or = 41 years). Total ovarian VI and VFI were significantly lower in women aged > or = 41 years. AFC had the best correlation with the age of women, followed by serum FSH concentration and ovarian 3D power Doppler indices. The rate of decline of total ovarian VI was 0.18% per year. CONCLUSION: Ovarian stromal blood flow was significantly reduced only in women aged > or = 41 years.

Adult↗

PubMed2004

A randomized study comparing the use of sublingual to vaginal misoprostol for pre-operative cervical priming prior to surgical termination of pregnancy in the first trimester.

BACKGROUND: Misoprostol is an effective agent for pre-operative cervical priming before surgical termination of pregnancy in the first trimester. Previous studies have shown that both oral and vaginal routes are equally effective for such a purpose. This study aimed to compare a new route of sublingual administration to the vaginal route of administration for pre-operative cervical priming in first trimester surgical abortion. METHODS: Eighty women with gestational age <12 weeks were randomized by a computer-generated model to receive 400 micro g of misoprostol either sublingually or vaginally 3 h prior to vacuum aspiration. The primary outcome measure was the degree of cervical dilatation, and secondary outcomes included the force required to dilate the cervix from 3 to 8 mm, intra-operative blood loss and incidence of pre-operative side-effects. RESULTS: There was no significant difference in the baseline cervical dilatation (sublingual: 7.6 +/- 1.3 mm; vaginal: 7.7 +/- 0.73 mm), cumulative force required to dilate the cervix from 3 to 8 mm (sublingual: 9.0 +/- 9.8 N; vaginal: 6.6 +/- 5.4 N) and total blood loss (sublingual: 52.1 +/- 20.2 ml; vaginal: 48.3 +/- 12.3 ml). Pre-operative side-effects were also similar. CONCLUSIONS: Both sublingual and vaginal misoprostol are effective in cervical priming before surgical termination of pregnancy in the first trimester. Sublingual misoprostol has the advantage of being more convenient to administer and may be more suitable for day surgery.

Abortifacient Agents, Nonsteroidal↗

PubMed2004

Concentrations of endometrial protein PP 14 and CA-125 in uterine flushings performed in natural and stimulated cycles.

BACKGROUND: Impaired implantation in assisted reproduction cycles with high serum estradiol (E(2)) concentrations may be attributed to abnormal endometrial development. This study compared concentrations of endometrial proteins in uterine flushings of infertile patients between natural and stimulated cycles. METHODS: Patients received a standard regimen of ovarian stimulation. Seven days after the LH surge in natural cycles or the hCG injection in stimulated cycles, uterine flushings were performed by slowly injecting and aspirating normal saline through a paediatric Foley catheter. Natural cycles were considered as group A whereas stimulated cycles with serum E(2) <20 000 pmol/l and serum E(2) >20 000 pmol/l were classified as groups B and C respectively. PP 14 and CA-125 in uterine flushings were measured and expressed per total protein content. RESULTS: Concentrations of the total protein, PP 14 and CA-125 in the uterine flushings were similar among the three groups. PP 14 per total protein in the uterine flushings was significantly correlated with serum E(2) on the day of hCG (r = 0.459; P = 0.009) in natural cycles only but not in stimulated cycles. CONCLUSION: There was no significant difference between natural and stimulated cycles in concentrations of PP 14 and CA-125 in uterine flushings performed in the mid-luteal phase.

Adult↗

PubMed2004

Endometrial and subendometrial blood flow measured during early luteal phase by three-dimensional power Doppler ultrasound in excessive ovarian responders.

BACKGROUND: Impaired implantation in assisted reproduction cycles with high serum estradiol (E(2)) concentrations may be related to suboptimal endometrial perfusion. Endometrial and subendometrial blood flow were compared between excessive responders (serum E(2) on the day of HCG >20 000 pmol/l) and moderate responders (E(2) < or =20 000 pmol/l). METHODS: Three-dimensional (3D) ultrasound examination with power Doppler was performed 2, 4 and 7 days after HCG in 32 patients who did not have embryo transfer in order to measure endometrial thickness, pulsatility index (PI)/resistance index (RI) of uterine vessels, and endometrial volume, vascularization index (VI)/flow index (FI)/vascularization flow index (VFI) of endometrial and subendometrial regions. RESULTS: Excessive responders tended to have lower endometrial and subendometrial VI/VFI on HCG +2 and more absent endometrial/subendometrial blood flow. They had significantly higher endometrial FI and subendometrial VFI than moderate responders on HCG +7. Only in the excessive responder group, uterine PI/RI declined significantly from HCG +2 to HCG +7 and endometrial VI/VFI increased significantly from HCG +4 to HCG +7. CONCLUSION: Changes in uterine Doppler flow indices, and endometrial and subendometrial 3D power Doppler flow indices during the early luteal phase were significantly different between moderate and excessive responders.

Adult↗

PubMed2004

The role and comparison of two techniques of paracervical block for pain relief during suction evacuation for first-trimester pregnancy termination.

This prospective study assessed the role and compared two techniques of paracervical block (PCB) for pain relief during suction evacuation for first-trimester termination of pregnancy following cervical priming with misoprostol. One-hundred and thirty-five women undergoing suction evacuation up to 12 weeks of gestation were randomized into three groups: (a) 5 mL of 1% lignocaine injected at the 4 and 8 o'clock positions of the vaginal vault; (b) 5 mL of 1% lignocaine injected at the 4 and 8 o'clock positions of the cervix and (c) no PCB. Pain scores during PCB, cervical dilatation and during and after suction evacuation were compared among the three groups. The sedation and satisfaction levels were also compared. There were no statistically significant differences in the pain levels during PCB, cervical dilatation and suction evacuation and in the satisfaction levels among the three groups. Patients with a lighter sedation level experienced more pain. In conclusion, PCB did not improve the pain levels during first-trimester suction termination of pregnancy after cervical priming with misoprostol and use of intravenous sedation, regardless of whether the local anaesthetic was injected into the cervix or the vaginal vault.

Abortion, Induced↗

PubMed2004

A prospective randomised comparison of sublingual and vaginal misoprostol in second trimester termination of pregnancy.

OBJECTIVE: To compare the efficacy, side effects and acceptability of sublingual and vaginal misoprostol for second trimester medical abortion. DESIGN: Prospective randomised controlled trial. SETTING: Tertiary referral unit and a teaching hospital. POPULATION: Two hundred and twenty-four women at 12 to 20 weeks of gestation. METHODS: The women were randomised to receive either sublingual or vaginal misoprostol 400 microg every 3 hours for a maximum of five doses. The course of misoprostol was repeated if the woman did not abort within 24 hours. MAIN OUTCOME MEASURES: The success rate at 48 hours, induction-to-abortion interval and the side effects. RESULTS: There was no significant difference in the success rate at 48 hours (sublingual: 91%; vaginal: 95%). However, the success rate at 24 hours was significantly higher in the vaginal group (85%) compared with the sublingual group (64%). There was no difference in the median induction-to-abortion interval (sublingual: 13.8 hours; vaginal: 12.0 hours). Significantly more women in the sublingual group preferred the route to which they were assigned when compared with the vaginal group. The incidence of fever was also less in the sublingual group. CONCLUSION: The use of vaginal misoprostol for second trimester medical abortion resulted in a higher success rate than sublingual misoprostol at 24 hours but the abortion rate was similar at 48 hours. Vaginal misoprostol should be the regimen of choice but sublingual misoprostol is also an effective alternative.

Abortifacient Agents, Nonsteroidal↗

PubMed2003

Is there any difference in pregnancy and implantation rates when nurses perform embryo transfer in an IVF-ET program?

A retrospective analysis of fresh in vitro fertilization treatment cycles and frozen embryo transfer (FET) cycles from mid-1995 to December 31, 1998, was undertaken. Nurses performed embryo transfer (ET) for government-funded cycles, whereas doctors performed ET for self-funded cycles. During the study period, fresh ET was performed in 1,165 treatment cycles. There were no significant differences in demographic data, ovarian responses and the number of embryos replaced between ET cycles performed by nurses and doctors. Pregnancy rates for ETs performed by nurses and doctors were 16.7 and 15.8% per transfer, respectively, whereas the corresponding implantation rates were 8.3 and 6.9%, respectively. Similar pregnancy and implantation rates were encountered in FET cycles whether ET was performed by nurses or doctors.

Adult↗

PubMed2003

A study of co-treatment of nonsteroidal anti-inflammatory drugs (NSAIDs) with misoprostol for cervical priming before suction termination of first trimester pregnancy.

This double-blind randomized control study was conducted to evaluate whether a nonsteroidal anti-inflammatory drug (NSAID) could act as an effective pain control method during first trimester suction abortion, and whether co-treatment of NSAID with misoprostol will decrease the efficacy of the cervical ripening effect of misoprostol. Subjects were randomized to receive misoprostol alone or misoprostol together with diclofenac sodium. Both groups of subjects suffered from similar incidence of preoperative side effects. Co-treatment of NSAID with misoprostol did not attenuate the cervical ripening efficacy of misoprostol. There was no significant pain reduction in the group treated with NSAID, except that a marginal benefit was found in the subgroup of multiparous women. About two thirds of the subjects in both treatment groups found that this was a satisfactory pain relief method during the procedure.

Abortifacient Agents, Nonsteroidal↗

PubMed2003

Pilot study on the use of sublingual misoprostol in termination of pregnancy up to 7 weeks gestation.

BACKGROUND: This study was conducted to assess the efficacy and incidence of side effects of a regimen of repeated doses of 400 microg sublingual misoprostol for termination of pregnancy of <7 weeks gestation. METHOD: Fifty women were given 400 microg sublingual misoprostol every 3 h for three doses. Two additional doses were given if necessary. RESULTS: Forty-three women (86%) had a complete abortion. Two women (4%) had incomplete abortion and 5 (10%) had an ongoing pregnancy. The median interval between the first dose of misoprostol and the passage of tissue mass was 14.1 h (3.25-561.6 h). The median duration of vaginal bleeding was 20 days (8-85 days). Side effects were mild and there was no significant drop in hemoglobin level. CONCLUSIONS: Our preliminary results on sublingual misoprostol show that it is a promising method for medical termination of pregnancy of <7 weeks. It may be used as an alternative for women who do not want surgical evacuation and who live in an area where mifepristone is not available.

Abortifacient Agents, Nonsteroidal↗