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Biomedical subjects

Ernest Hung Yu Ng

Publications and source records attributed to Ernest Hung Yu Ng.

At least 19 recordsLinked to original sources
PubMed2006

Endometrial and subendometrial vascularity is higher in pregnant patients with livebirth following ART than in those who suffer a miscarriage.

BACKGROUND: Blood flow towards the peri-implantation endometrium may have effects on miscarriage and live birth following assisted reproduction treatment, in addition to its role in implantation. METHODS: Three-dimensional ultrasound examination with power Doppler was performed on the day of oocyte retrieval in stimulated IVF cycles and on LH + 1 day in frozen thawed-embryo transfer (FET) cycles to measure endometrial thickness, endometrial pattern, uterine artery Doppler flow indices, endometrial volume, vascularization index (VI), flow index (FI), vascularization flow index (VFI) of endometrial and subendometrial regions. RESULTS: In stimulated IVF cycles, 45 (28.0%) out of 161 pregnant patients subsequently miscarried. Patients in the live birth group had significantly higher endometrial VI and VFI and subendometrial VI, FI and VFI, when compared with those in the miscarriage group. In a multiple logistic regression analysis, only endometrial VI was significantly associated with the chance of live birth with an odds ratio of 1.384 [95% confidence interval (CI) 1.025-1.869, P = 0.034]. For FET cycles, patients in the live birth group had significantly higher endometrial VFI, subendometrial VI and VFI than those in the miscarriage group. CONCLUSIONS: Endometrial and subendometrial vascularity was significantly higher in pregnant patients with live birth following stimulated IVF and FET treatment than in those who suffered a miscarriage.

Abortion, Spontaneous↗
PubMed2006

Ageing and ART: a waste of time and money?

In many societies, more and more young women are delaying childbearing until the fourth decade of life. It is well known that fertility is remarkably reduced with increasing age of women in both natural conceptions and assisted reproductive technology (ART). In this chapter, the effect of ageing on the pregnancy rate in ART, and the options available to improve the reproductive outcomes in women of advanced age will be presented after understanding the mechanism of reproductive ageing and the effects of ageing on the reproductive outcomes in normal women. It is important to identify the predictive factors associated with a better treatment outcome.

Adult↗
PubMed2006

A randomized comparison of side effects and patient convenience between Cyclogest suppositories and Endometrin tablets used for luteal phase support in IVF treatment.

OBJECTIVE: This study compared side effects and patient convenience of vaginal progesterone suppositories (Cyclogest) and vaginal progesterone tablets (Endometrin) used for luteal phase support in in vitro fertilization/embryo transfer (IVF/ET) cycles using pituitary downregulation. STUDY DESIGN: One hundred and thirty-two infertile patients were randomized on the day of ET by a computer-generated randomization list in sealed envelopes to receive either Cyclogest 400mg or Endometrin 100mg twice daily for 14 days. On days 6 and 16 after ET, they rated side effects and patient convenience into four grades: none, mild, moderate and severe by completing a questionnaire. RESULTS: No significant differences in perineal irritation were found on days 6 and 16 after ET between the two groups, although there was a trend of fewer patients with perineal irritation in the Endometrin group. Significantly more patients in the Endometrin group had difficulty of administration on day 6 after ET. There were no differences in the hormonal profile on day 6 after ET and IVF outcomes between the two groups. CONCLUSION: There was no difference in perineal irritation after the use of Cyclogest suppositories or Endometrin tablets for luteal phase support although more patients found administration of Endometrin tablets difficult.

Adult↗
PubMed2006

A double-blind, randomized controlled trial on the use of a 50:50 mixture of nitrous oxide/oxygen in pain relief during suction evacuation for the first trimester pregnancy termination.

BACKGROUND: This prospective study assessed the role of a 50:50 mixture of nitrous oxide (N2O) and oxygen for pain relief during the termination of first trimester pregnancies by suction evacuation under conscious sedation. METHODS: Ninety women undergoing suction evacuation up to 12 weeks of gestation were randomized by a computer-generated randomization list and allocated using sealed envelopes to receive the N2O/O2 mixture or air during the operation. Pain scores during and after suction evacuation, post-operative side effects and satisfaction level were compared. RESULTS: No statistically significant differences in pain scores, post-operative side effects and satisfaction levels were found between the two groups. CONCLUSION: N2O/O2 did not reduce the pain level during suction evacuation for the first trimester pregnancy termination under conscious sedation.

Abortion, Induced↗
PubMed2006

Perifollicular vascularity in poor ovarian responders during IVF.

BACKGROUND: Normal ovarian responders who have follicles with good vascularity shown by power Doppler scanning are associated with a better pregnancy rate following IVF treatment. This study evaluated the significance of perifollicular vascularity and follicular fluid hormonal profile in poor responders who developed < or = 3 dominant follicles. METHODS: Before oocyte retrieval, they underwent power Doppler examination for perifollicular vascularity. Patients who had all follicles with low-grade vascularity were classified as Group A, whereas those with at least one follicle with high-grade vascularity were Group B. Their follicular fluid concentrations of estradiol (E2), progesterone, HCG, vascular endothelial growth factor (VEGF) and inhibin B were measured. RESULTS: A total of 58 consecutive patients were recruited: 38 in Group A and 20 in Group B. Implantation rate, clinical pregnancy rate and follicular fluid hormonal concentrations were comparable for Groups A and B. Multiple pregnancy and live birth rates appeared higher, whereas miscarriage rate were lower in Group B than Group A, but these differences did not reach statistical significance. CONCLUSION: There were no significant differences in the implantation, clinical pregnancy and live birth rates among poor responders with and without high-grade perifollicular vascularity.

Abortion, Spontaneous↗
PubMed2006

The role of endometrial and subendometrial vascularity measured by three-dimensional power Doppler ultrasound in the prediction of pregnancy during frozen-thawed embryo transfer cycles.

BACKGROUND: A good blood supply to the endometrium is usually considered as an essential requirement for implantation. OBJECTIVE: The aim of this study was to evaluate the role of endometrial and subendometrial vascularity in the prediction of pregnancy during frozen-thawed embryo transfer (FET) cycles. METHODS: Women undergoing FET in natural or clomiphene-induced cycles after the first stimulated IVF treatment were recruited. A three-dimensional (3D) ultrasound examination with power Doppler was performed 1 day after the LH surge to determine endometrial thickness, endometrial pattern, pulsatility index (PI) and resistance index (RI) of uterine vessels, endometrial volume, vascularization index, flow index and vascularization flow index of endometrial and subendometrial regions. RESULTS: Women in the pregnant group were significantly younger and used less gonadotrophins in their stimulated cycle. Endometrial thickness, endometrial volume, endometrial pattern, uterine PI, uterine RI, endometrial and subendometrial 3D power Doppler flow indices were similar between the nonpregnant and the pregnant groups. The age of women was the only predictive factor for pregnancy. Receiver operating characteristic curve analysis revealed that the area under the curve was around 0.5 for all ultrasound parameters for endometrial receptivity. CONCLUSION: Vascularity of endometrial and subendometrial layers measured by 3D power Doppler ultrasound is not a good predictor of pregnancy in FET cycles if measured at one time point only.

Adult↗
PubMed2006

Comparison of endometrial and subendometrial blood flows among patients with and without hydrosalpinx shown on scanning during in vitro fertilization treatment.

OBJECTIVE: To compare endometrial and subendometrial blood flows among patients with and without hydrosalpinx (HSP) during in vitro fertilization treatment as measured by a three-dimensional power Doppler ultrasound. DESIGN: A prospective observational study. SETTING: A tertiary assisted-reproduction unit. PATIENT(S): Twenty-one patients with HSP were compared with 42 matched controls without HSP. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Endometrial thickness, endometrial pattern, endometrial volume, pulsatility index (PI) and resistance index (RI) of uterine vessels, and the vascularization index (VI), flow index (FI), and vascularization flow index (VFI) of endometrial and subendometrial regions were measured on the day of oocyte retrieval. RESULT(S): The proportion of the non-multilayered endometrial pattern was significantly higher in the HSP group than in the non-HSP group. Patients in the HSP group had significantly lower endometrial and subendometrial VI and VFI. Endometrial thickness, endometrial volume, uterine PI, uterine RI, and endometrial and subendometrial FI were similar between the two groups. No significant differences were observed in endometrial and subendometrial VI, FI, and VFI among patients with unilateral and bilateral HSP. CONCLUSION(S): A change in endometrial pattern and a decrease in endometrial and subendometrial blood flows may be the reasons for impaired implantation in patients with HSP.

Adult↗
PubMed2006

Ovarian stromal vascularity is not predictive of ovarian response and pregnancy.

The role of ovarian stromal vascularity in the prediction of the ovarian response and pregnancy in infertile women was evaluated by comparing age of women, body mass index (BMI), basal FSH concentration, antral follicle count (AFC) and ovarian stromal vascularity indices measured by three-dimensional power Doppler ultrasound. A total of 111 women in their first IVF cycle were analysed. They were aged <40 years with basal FSH concentration <10 IU/l on recruitment for IVF treatment. AFC, mean ovarian volume and mean ovarian 3D power Doppler flow indices were determined on day 2 of the treatment cycle prior to a standard regimen of ovarian stimulation. Ovarian response was represented by the number of oocytes, serum oestradiol, the duration and dosage of gonadotrophins. AFC achieved the best predictive value in relation to the number of oocytes obtained, followed by age of women and BMI. Basal FSH concentration was the only predictive factor for the duration and dosage of gonadotrophin used. Mean ovarian 3D power Doppler flow indices were not predictive of pregnancy in a multiple logistic regression analysis. Ovarian 3D power Doppler flow indices measured after pituitary down-regulation were not predictive of the ovarian response and pregnancy in the IVF treatment.

Adult↗
PubMed2005

Factors affecting endometrial and subendometrial blood flow measured by three-dimensional power Doppler ultrasound during IVF treatment.

BACKGROUND: No information exists in the literature regarding the factors affecting the blood flow towards the endometrial and subendometrial regions during IVF treatment. METHODS: We examined the effect of women's age, their smoking habits, their type of infertility (i.e. primary or secondary) and parity, causes of infertility and serum estradiol (E2) concentration on endometrial and subendometrial blood flows as measured by a three-dimensional (3D) power Doppler ultrasound during IVF treatment. All patients received a standard long protocol of ovarian stimulation and serum E2 concentration was determined on the day of hCG. 3D ultrasound examination with power Doppler was performed on the day of oocyte collection to determine vascularization index (VI), flow index (FI) and vascularization flow index (VFI) of endometrial and subendometrial regions. RESULTS: The age of women, their smoking habits, their types of infertility and parity and causes of infertility had no effect on the endometrial and subendometrial 3D power Doppler flow indices. There was a negative correlation between serum E(2) concentration and endometrial FI (r = -0.109; P = 0.006). CONCLUSIONS: Endometrial blood flow in IVF treatment was negatively affected by serum E2 concentration only.

Adult↗
PubMed2005

The role of endometrial and subendometrial blood flows measured by three-dimensional power Doppler ultrasound in the prediction of pregnancy during IVF treatment.

BACKGROUND: A good blood supply towards the endometrium is usually considered to be an essential requirement for implantation. We aimed to evaluate the role of endometrial and subendometrial blood flows in the prediction of pregnancy during IVF treatment. METHODS: Patients undergoing the first IVF cycle were recruited. A three-dimensional (3D) ultrasound examination with power Doppler was performed on the day of oocyte retrieval to determine endometrial thickness, endometrial pattern, pulsatility index (PI) and resistance index (RI) of uterine vessels, endometrial volume, vascularization index (VI), flow index (FI) and vascularization flow index (VFI) of endometrial and subendometrial regions. RESULTS: Uterine RI, endometrial VI and VFI were significantly lower in the pregnant group than the non-pregnant group. There was a non-significant trend of higher implantation and pregnancy rates in patients with absent endometrial or subendometrial blood flow. The number of embryos replaced and endometrial VI were the only two predictive factors for pregnancy. Receiver operator characteristic curve analysis revealed that the area under the curve was approximately 0.5 for all ultrasound parameters for endometrial receptivity. CONCLUSION: Endometrial and subendometrial blood flows measured by 3D power Doppler ultrasound were not good predictors of pregnancy if they were measured at one time-point during IVF treatment.

Adult↗
PubMed2005

Ovarian stromal blood flow in the prediction of ovarian response during in vitro fertilization treatment.

BACKGROUND: This study evaluated the role of ovarian stromal blood flow in the prediction of the ovarian response of infertile women by comparing age of women, body mass index (BMI), basal FSH concentration, antral follicle count (AFC) and ovarian stromal blood flow indices measured by power Doppler in two-dimensional ultrasound. Patients were aged <40 years with basal FSH <10 IU/l on recruitment for IVF treatment. METHODS: All received a standard regimen of ovarian stimulation in their first IVF cycle. AFC, pulsatility index, resistance index and peak systolic blood flow velocity of ovarian stromal vessels were determined on the second day of the treatment cycle prior to ovarian stimulation. Ovarian response was represented by the number of oocytes, serum oestradiol, and the duration and dosage of gonadotrophins. RESULTS: A total of 136 women were included in the analysis. Basal FSH concentration achieved the best predictive value in relation to the number of oocytes obtained, followed by AFC and BMI. AFC was the only predictive factor of serum oestradiol concentration on the day of HCG while BMI was predictive of the gonadotrophin dosage. CONCLUSION: Ovarian stromal blood flow indices measured by power Doppler ultrasound had no predictive value for the ovarian response.

Adult↗
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

Increased cystic fibrosis transmembrane conductance regulator (CFTR) expression in the human hydrosalpinx.

BACKGROUND: Hydrosalpinx (HSP), characterized by abnormal fluid accumulation in the Fallopian tube, is one of the main causes of infertility in women; however, the mechanism underlying the formation of hydrosalpinx fluid (HF) remains elusive. The present study investigated the possible involvement of cystic fibrosis transmembrane conductance regulator (CFTR), a cAMP-dependent chloride channel, in the pathogenesis of hydrosalpinx. METHODS: Masson's trichrome staining was used to characterize epithelial transformation in human HSP; RT-PCR, immunohistochemistry and immunofluorescence staining were used for CFTR expression and localization. RESULTS: Masson's trichrome staining showed areas of epithelial transformation, focally attenuated and pseudostratified. Immunostaining showed enhanced CFTR immunoreactivity in the focally attenuated and pseudostratified areas of HSP epithelium. RT-PCR revealed that CFTR expression in HSP was significantly greater than that in normal Fallopian tubes. CONCLUSIONS: These results indicate that HSP epithelium undergoes epithelial transformation with elevated CFTR expression, which may lead to increased transepithelial electrolyte and fluid secretion resulting in HF formation. The present findings may lead to the development of new treatment strategies for infertile patients with HSP.

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

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↗
PubMed2005

Ultrastructural characterization of whole hydrosalpinx from infertile Chinese women.

Hydrosalpinx (HSP) has been shown to be detrimental to the outcome of assisted reproduction, but little is known of its pathology. This prospective study examined and detailed ultrastructural characterization of HSP of infertile women presenting for assisted reproductive treatments. Both light and electron microscopies were used to characterize HSP. Hematoxylin and eosin staining of HSP showed areas without epithelial cell lining or with abnormalities such as flattening of the epithelial layer and exfoliation of epithelial cells with occasional normal columnar epithelial lining. HSP muscle fibers were atrophic and occasionally replaced by fibrous tissues, or separated by areas of severe edema. Inflammatory cells could be found in hydrosalpinx fluid (HF) in the lumen in areas with flattened to no epithelial cells, without epithelial lining, as well as in dilated blood vessels and/or lymph vessels. Scanning electron microscopy of the epithelial surface revealed epithelial denudation-severe loss of both cilia and microvilli and stomata exuding globular bodies on eroded ampulla surfaces. Severe chronic inflammation and damage to the epithelial lining and musculature of Fallopian tubes and the presence of inflammatory cells provides an explanation for HF formation, and thus for the detrimental effects of HF on reproductive processes and IVF outcome.

Adult↗