Biomedical subjects

Pak Chung Ho

Publications and source records attributed to Pak Chung Ho.

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

Women's perceptions on medical abortion.

The reasons why women choose medical abortion vary in different countries. In most countries, the most common reasons for choosing medical abortion are as follows: (a) avoidance of surgery or general anesthesia; (b) perception that it is safer; and (c) perception that it is more natural than a surgical procedure. In most studies, over 80% of women who chose medical abortion found it acceptable and would choose the same method again if they needed another abortion in the future. They would also recommend this procedure to other women who need an abortion. In selected women, the administration of misoprostol at home was also acceptable. The acceptability of medical abortion may decrease with increasing gestational age of pregnancy, failure of medical abortion, prolonged bleeding and high levels of discomfort and anxiety during the abortion procedure. There was no significant difference in the emotional responses or incidences of psychiatric morbidity between women undergoing medical and women undergoing surgical abortion.

Abortion, Induced↗

PubMed2006

The pharmacokinetics and different regimens of misoprostol in early first-trimester medical abortion.

Misoprostol is a synthetic prostaglandin E(1) analogue that is commonly used for medical abortion. It can be given orally, vaginally and sublingually. A pharmacokinetic study has shown that sublingual misoprostol has the shortest onset of action, the highest peak concentration and the greatest bioavailability among the three routes of administration. Earlier clinical trials have shown that vaginal misoprostol is superior to oral misoprostol when combined with mifepristone for early first-trimester medical abortion. Recent studies on the clinical efficacy of sublingual misoprostol have demonstrated that it is as effective as vaginal misoprostol. Further studies are required to determine the optimal dose and route of administration of misoprostol that can give the highest complete abortion rate, lowest ongoing pregnancy rate and least side effects.

Abortifacient Agents, Nonsteroidal↗

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↗

PubMed2006

Clinical applications of mifepristone.

Mifepristone is a progesterone antagonist that has been studied for a number of clinical applications. It is a well-known abortifacient that is effective for both first- and second-trimester medical abortion when used with a prostaglandin analog. It is also an effective cervical priming agent that can be used to soften the cervix before surgical evacuation. Its clinical efficacy as an emergency contraception has been proven. Other applications including treatment for fibroids, endometriosis and various cancers have been explored. However, its association with abortion limits the applications of mifepristone in many of these areas.

Abortifacient Agents, Steroidal↗

PubMed2006

Nuchal translucency in pregnancies conceived after assisted reproduction technology.

PURPOSE OF REVIEW: Nuchal translucency is one of the important markers in the first trimester during antenatal screening for fetal Down's syndrome. With the observation of alterations in biochemical markers in pregnancies conceived after assisted reproduction, this review presents current information related to the thickness of nuchal translucency in these pregnancies. RECENT FINDINGS: Early small studies did not demonstrate any discrepancy in the thickness of nuchal translucency in fetuses from assisted reproduction and from spontaneous pregnancies, but there has been recent evidence to suggest an increased level of nuchal translucency in singletons from various modes of assisted-reproduction technology. Nuchal translucency in twins following assisted reproduction did not, however, show a similar increase. Although the effect of chorionicity was not specifically addressed, nuchal translucency thickness in twins born after assisted reproduction was reported to be comparable to that in spontaneous singletons. It is possible that singletons and twins after assisted reproduction exhibit different antenatal behavior and pregnancy courses. SUMMARY: Similar to other biochemical markers of fetal Down's syndrome, nuchal translucency is increased in singletons after assisted-reproduction technology. Further studies on twin pregnancies, in particular dichorionic twins, are necessary before conclusive evidence can be drawn for multiple pregnancies.

Down Syndrome↗

PubMed2006

The use of misoprostol for early pregnancy failure.

PURPOSE OF REVIEW: This paper reviews the current management of early pregnancy failure with particular emphasis on the use of misoprostol. RECENT FINDINGS: Medical management using misoprostol is effective for the management of miscarriages. The success rate ranged from 84 to 93% depending on the regimen of misoprostol, the duration of waiting period and the types of miscarriage. SUMMARY: Miscarriages occur in 10 to 20% of all pregnancies. Surgical evacuation has been used to empty the uterus. Recently, medical treatment using misoprostol has been studied for the management of miscarriage. It avoids surgery and its associated complications. Compared to expectant management, the success rate is higher. Nonsurgical management takes a longer period to reach the endpoint and medical management is associated with side effect of medication. Studies have shown that medical management is safe and acceptable to women. The optimal regimen of medical management, however, is yet to be determined.

Abortifacient Agents, Nonsteroidal↗

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

A randomized trial to compare the use of sublingual misoprostol with or without an additional 1 week course for the management of first trimester silent miscarriage.

BACKGROUND: This randomized controlled trial compared the use of sublingual misoprostol with or without an additional 1 week course of sublingual misoprostol for the medical management of silent miscarriage. METHODS: A total of 180 women who had silent miscarriage (<13 weeks) was given 600 microg of misoprostol every 3 h for a maximum of three doses. These women were randomized into two groups: (i) no extended course of misoprostol or (ii) an extended course of sublingual misoprostol 400 microg daily for 1 week. The primary outcome measure was complete miscarriage rate. RESULTS: The success rates for complete miscarriage were similar in both groups (group 1: 92.2%; 95% CI: 86.1-97.5% and group 2: 93.2%; 95% CI: 84.6-96.8%). There were no serious complications. The incidence of diarrhoea was higher (P < 0.01) in the group with an extended course of sublingual misoprostol. Other side-effects were similar. CONCLUSION: Sublingual misoprostol is useful for the management of silent miscarriage. An additional 1 week course of sublingual misoprostol did not improve the success rate or shorten the duration of vaginal bleeding. Instead, it increased the incidence of diarrhoea.

Abortifacient Agents, Nonsteroidal↗

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

A prospective randomized comparison of sublingual and oral misoprostol when combined with mifepristone for medical abortion at 12-20 weeks gestation.

BACKGROUND: Sublingual misoprostol has been shown to be effective in medical abortion. A prospective double-blinded placebo-controlled trial was done to compare the efficacy and side-effects of sublingual to oral misoprostol when used with mifepristone for medical abortion from 12 to 20 weeks gestation. METHODS: A total of 120 women at 12-20 weeks of gestation were randomized to receive 200 mg oral mifepristone followed by either sublingual or oral misoprostol 400 mg every 3 h for a maximum of five doses 36-48 h later. The course of misoprostol was repeated if the woman did not abort within 24 h. RESULTS: There was no significant difference (P = 0.43) in the success rate at 24 h [relative risk = 1.075; 95% confidence interval (CI): 0.94-1.19]. Abortion occurred in 91.4% in the sublingual group (95% CI: 81.0-96.7%) as compared to 85.0% (95% CI: 73.7-92.1%) in the oral group. The median induction-to-abortion interval was significantly shorter (P = 0.009) in the sublingual group (5.5 h) as compared to the oral group (7.5 h). The incidence of fever was higher in the sublingual group (P < 0.0001). The incidences of other side-effects were similar. CONCLUSION: Sublingual misoprostol, when combined with mifepristone, is effective for medical abortion in the second trimester. The induction-to-abortion interval is shorter when sublingual misoprostol is used when compared to oral misoprostol.

Abortifacient Agents, Nonsteroidal↗

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↗