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Biomedical subjects

Ernest Hung Yu Ng

Publications and source records attributed to Ernest Hung Yu Ng.

At least 37 records · Page 2Linked to original sources
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

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↗
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 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

Characterization of epithelial cell culture from human hydrosalpinges and effects of its conditioned medium on embryo development and sperm motility.

BACKGROUND: Recent studies have reported the negative impact of hydrosalpinx on IVF outcome. Toxic effects of hydrosalpinx fluid (HF) have been the main reason for the recommendation of functional surgery, salpingectomy, prior to IVF. The present study characterized hydrosalpinx epithelial cell culture and examined the effects of its conditioned medium (CM) on sperm motility, acrosome reaction and embryo development. METHODS: Normal Fallopian tubes (n = 6) and hydrosalpinges (n = 9) were used to prepare epithelial cell culture and CM. Epithelial cell characterization was confirmed using electron microscopy. Sperm motility and acrosome reaction were determined using computer-aided sperm analysis and acrobead assay respectively and embryo development by mouse embryo development assay. RESULTS: The percentage of human motile sperm incubated in hydrosalpinx CM was significantly different from those in normal Fallopian tube (NFT) CM and modified human tubal fluid medium (hTF) (control) (P < 0.05 at 3 h and P < 0.001 at 5 and 24 h), with alteration in movement characteristic, linearity, 24 h after incubation in hydrosalpinx CM (P < 0.05). However, other sperm movement characteristics remained unchanged. Reduced acrosome reaction and poor mouse embryo development were also observed in hydrosalpinx CM but not in NFT CM and hTF. CONCLUSIONS: The results suggest that hydrosalpinx epithelial cells may be producing a fluid milieu hostile to sperm and early embryo development. The established epithelial cell culture system may provide a model to further investigate the mechanisms underlying the toxic effects of HF on embryo development and the adverse effects on IVF outcomes.

Acrosome Reaction↗
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 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↗