PubMed Health⌕ Search

Biomedical subjects

Y F Fong

Publications and source records attributed to Y F Fong.

At least 19 recordsLinked to original sources
PubMed2005

Hemostatic status and fibrinolytic response potential at different phases of the menstrual cycle.

Coagulation and fibrinolytic variables including platelet function and endogenous fibrinolytic response were determined in 30 normal healthy women volunteers not on any known medication during the period of study. They were between 18 years and 38 years old and had normal menstrual cycles of between 28 days and 30 days. Blood samples were obtained within one menstrual cycle and after having fasted overnight within days 1 to 3 (menstruation), 5 to 9 (follicular), 10 to 14 (mid-cycle), and 21 to 26 (luteal) of the menstrual cycle. Analysis of variance (ANOVA) showed no significant differences in the hemostatic parameters studied between the phases of the menstrual cycle except for a reduced D-dimer level at midcycle. Significant fibrinolytic response was seen after venous occlusion but they were not significantly different between the phases of the menstrual cycle. The women were then divided into either normal weight (n=22) or overweight (n=8) according to World Health Organization (WHO) classification and the data reanalyzed. Elevated tissue plasminogen activator antigen and plasminogen activator inhibitor-1 levels except at menstruation and total protein S except at follicular phase were observed in overweight women together with increased plasminogen level only at luteal phase. Significant endogenous fibrinolytic response seen during the menstrual cycle was not different between normal and overweight women. The study demonstrated that systemic coagulation, fibrinolysis, and platelet function were probably not influenced by natural hormonal changes occurring during the menstrual cycle except for an associated reduced fibrinolytic state at mid-cycle. The hemostatic system in this small group of healthy overweight women studied appeared to be physiologically compromised.

Adolescent↗
PubMed2003

A viable alternative to surgical vacuum aspiration: repeated doses of intravaginal misoprostol over 9 hours for medical termination of pregnancies up to eight weeks.

OBJECTIVE: To study the efficacy of repeated doses of vaginal misoprostol over 9 hours in a day care setting for terminating pregnancies up to eight weeks of gestation. DESIGN: An open, single arm prospective study conducted between January 2000 and December 2001. SETTING: Fertility Control Clinic, National University Hospital, Singapore. POPULATION: One hundred and fifty pregnant women with an unwanted pregnancy up to eight weeks of gestation requesting medical abortion. METHODS: The women were given an initial dose of 800 microg of vaginal misoprostol. A further dose of 400 microg was repeated every 3 hours for a maximum of three doses. MAIN OUTCOME MEASURES: The complete abortion rate defined as successful cases that did not require vacuum aspiration. RESULTS: The complete abortion rate was 84.7% and 96.0% at 15 days and 43 days after initial administration of vaginal misoprostol. The mean interval between first dose of misoprostol and the onset of expulsion of products of conception (SD) was 8.1 hours (6.3). The mean and the median percentage changes in the serum beta-hCG levels at day 15 as compared with pre-abortion levels were statistically significant (P < 0.001) and were a good predictor of the likely outcome of the medical abortion. The mean duration of bleeding (SD) was 11.7 days (4.7) and the mean duration between the onset of procedure and the return of normal menstruation (SD) was 35.5 days (5.7). There was no significant change in haemoglobin concentration. Lower abdominal pain, fever (>38.0 degrees C) and diarrhoea were the most common side effects. CONCLUSIONS: This regimen of repeated doses of vaginal misoprostol every 3 hours over a period of 9 hours, in keeping with the plasma level and pharmacokinetic of misoprostol administered vaginally, is an effective method of medical abortion that approaches the efficacy of surgical vacuum aspiration. The regimen would offer a suitable option for women requesting termination of pregnancy up to eight weeks of gestation in countries where mifespristone is and will never be made available.

Abortifacient Agents↗
PubMed2002

Profile of women presenting for abortions in Singapore at the National University Hospital.

The study was conducted to profile women seeking abortions at the National University Hospital, with particular interest in the trend of teenage pregnancies with the aim of identifying risk factors for late presentation for abortions. All patients who underwent an abortion at our center from January 1, 1996 to December 31, 2000 were recruited. Data were entered into a prepared questionnaire during the mandatory pre-abortion counseling sessions and completed at the 6-week post-abortion follow-up. This was then keyed into a database (SPSS Version 10), and the results were analyzed. Multivariate analysis was used in identifying risk factors associated with late presentation for abortions. Chi-square analysis of variables was used where relevant. A total of 1370 women presented for induced abortions during the period of study. The mean age of women was 29.6 years. Most women were either homemakers (35.3%) or semi-skilled workers (28.5%) with at least a secondary school education (58.3%). The majority were married (75.5%). There was a significant trend in the proportion of single women seeking abortions, from 18.3% in 1996 to 27.8% in 2000 (p < 0.05). At the same time, the proportion of women presenting for repeat abortions also increased from 13.8% in 1996 to 33.2% in 2000 (p < 0.05). Teenage abortions made up 117 (8.5%) of the study group, of which 95% were single women. Significant proportions (52.1%) were students at the time of abortion. In contrast to women above 20 years of age, pregnant teenagers were more likely not to have used any contraception (67.1% vs. 37.3%) and more likely to present late for abortion (18.8% vs. 10.4%). Teenage pregnancies are a major risk factor for late presentation for abortions. This emphasizes the need for availability and easy access to early abortion counseling, and the need for sex education with use of contraception starting in schools, to reduce abortions among teenagers.

Abortion, Induced↗
PubMed2000

Gynaecology in the new millennium.

Great challenges await the gynaecologist in the 21st century. While advances in medical technology necessitate that gynaecology move more towards a medical discipline than a surgical one, gynaecologists will be expected to play an increasingly important role in the modern woman's life. This fundamental change is influenced by four main factors, namely, the world's aging population, spread of information technology, advances in molecular based medical therapy, and the changing lifestyle of the woman in the next century. Our role cannot get any lesser as we continue to advise, educate and facilitate the lives of women, and we must aspire a new generation of responsible gynaecologists to continue this ambition.

Aging↗
PubMed1999

Effect of the levonorgestrel-releasing intrauterine system on uterine myomas in a renal transplant patient.

The levonorgestrel-releasing intrauterine system (LNG-IUS) has been used in the treatment of both idiopathic menorrhagia and adenomyosis. An electronic search of the on-line medical literature revealed no reports of its use for menorrhagia secondary to uterine myomas. Presented here is the successful treatment of uterine myomas with menorrhagia in a woman with a renal transplant. There was a significant reduction in menorrhagia, dysmenorrhea, and uterine and myoma size with the use of the LNG-IUS. We believe that this system provides an alternative to conventional hysterectomy and gonadotrophin-releasing hormonal analog medical treatment for uterine myomas, with a possibly inhibitory effect on myoma growth.

Adult↗
PubMed1999

Medical treatment of a grossly enlarged adenomyotic uterus with the levonorgestrel-releasing intrauterine system.

Adenomyosis is an important cause of menorrhagia. Besides hysterectomy, the treatment options for adenomyosis have been limited. Presented here is the successful treatment of adenomyosis in a woman presenting with menorrhagia, dysmenorrhea, and an enlarging uterus, for whom conservative therapy initiated with mefenamic acid was unsatisfactory. The patient had insertion of the levonorgestrel-releasing intrauterine system (LNG-IUS). A marked decrease in uterine size occurred within 12 months of insertion accompanied by resolution of the menorrhagia and dysmenorrhea. Thus, the LNG-IUS is a viable option and represents a real advance in the treatment of adenomyosis.

Adult↗
PubMed1999

Evacuation interval after vaginal misoprostol for preabortion cervical priming: a randomized trial.

OBJECTIVE: To determine the optimal interval for evacuation after preabortion cervical priming with vaginal misoprostol. METHODS: One hundred eighty healthy nulliparas requesting legal termination of pregnancy between 6 and 11 weeks' gestation were assigned randomly to receive 400, 600, or 800 microg of intravaginal misoprostol. Vacuum aspiration was done after 3 hours in the 400-microg group and after 2 hours in the 600- and 800-microg groups. The degree of cervical dilatation before operation was measured with a Hegar dilator. Preoperative and intraoperative blood loss and associated side effects were also assessed. RESULTS: Eleven (18.3%) and 15 (25.0%) women in the 600-and 800-microg groups, respectively, had cervical dilatation of at least 8 mm after an interval of 2 hours; 55 (91.7%) women who received 400 microg for a 3-hour interval had similar cervical dilatation. Using 400 microg as a baseline, the odds ratio (OR) was 0.02; 95% confidence interval (CI) was 0.01, 0.06 for 600 microg and OR 0.03; 95% CI 0.01, 0.09 for 800 microg for achieving successful preabortion cervical dilatation of at least 8 mm. The mean cervical dilatation of 6.7 mm and 6.8 mm for the higher doses was also significantly less than that of 8.1 for the 400-microg dose (P<.001). The mean preoperative and intraoperative blood loss was only statistically different when the 400- and 800-microg groups were compared (P = .03). There were also significantly more side effects, namely abdominal pain and fever above 38.0 C, in the 600- and 800-microg groups (P<.001), compared with the 400-microg group. When the 600- and 800-microg groups were compared, there were still significantly more women complaining of abdominal pain (P<.001). None of the women in the study required analgesics for pain or antipyretics for fever. CONCLUSION: The minimal evacuation interval should be at least 3 hours for successful preabortion cervical priming.

Abortifacient Agents, Nonsteroidal↗
PubMed1999

Does an acidic medium enhance the efficacy of vaginal misoprostol for pre-abortion cervical priming?

Absorption pharmacokinetics reveal a relationship between plasma concentrations of misoprostol and its therapeutic effect. To achieve a constant plasma profile and optimal efficacy, it is important to develop a medium that ensures complete dissolution of vaginal misoprostol tablets. Vaginal misoprostol is said to liquefy better in an acidic medium; thus, the aim of this study was to determine whether a 200 microg misoprostol tablet dissolved in acetic acid would be more efficacious than 200 microg misoprostol dissolved in water for pre-abortion cervical priming. A total of 120 healthy nulliparous women requesting legal termination of pregnancy between 6-12 weeks gestation were allocated randomly to either of the study groups. Vacuum aspiration was performed 3-4 h after insertion of the misoprostol tablet. Using Hegar's dilator, the degree of cervical dilatation before operation was measured. Of 60 women, 14 (23%) achieved a cervical dilatation of >/=8 mm when the misoprostol dose was dissolved in acetic acid; 12 (20%) achieved a similar cervical dilatation when the dose was dissolved in water. The mean cervical dilatation for the acid and water media used was 6.3 mm and 6.2 mm respectively; these differences were not statistically significant, neither were pre-operative and intra-operative blood losses statistically different between the two groups. Twenty-four (40%) and four (7%) respectively of women in whom a water medium was used experienced vaginal bleeding and abdominal pain; 20 (33%) and 0 women respectively among those in whom an acetic acid medium was used experienced vaginal bleeding and abdominal pain. These differences in side effects were not statistically significant. Our study shows that the use of acetic acid to dissolve vaginal misoprostol does not improve the efficacy in achieving successful cervical dilatation for pre-abortion cervical priming.

Abortifacient Agents, Nonsteroidal↗
PubMed1999

Vaginal misoprostol for pre-abortion cervical priming: is there an optimal evacuation time interval?

OBJECTIVE: To determine the optimal evacuation time interval in the use of vaginal misoprostol for cervical priming before first trimester termination of pregnancy. DESIGN: Prospective double-blind randomised study. SETTING: Fertility Control Centre, National University Hospital, Singapore. METHODS: Sixty healthy nulliparous women requesting legal termination of pregnancy between 6 and 11 weeks of gestation were randomly allocated to either the 400 microg or 600 microg misoprostol group. Vacuum aspiration was performed after three hours in the 400 microg group and at the end of two hours in the women given 600 microg misoprostol. Using Hegar's dilator, degree of cervical dilatation before operation was measured. Other parameters assessed included the amount of additional dilatation required (if < Hegar 8), pre-operative and intra-operative blood loss, and associated side effects. RESULTS: For the 600 microg group, only five women (16.7%) achieved a cervical dilatation of > or = 8 mm, compared with 28 women (93.3%) in the 400 microg group. Using the 400 microg misoprostol group as a baseline, the odds ratio was 0.014 (95% CI 0.003-0.080) for 600 microg for successful pre-operative cervical dilatation of > or = 8 mm. The mean cervical dilatation for 400 and 600 microg misoprostol was 8.1 mm and 6.6 mm, respectively (P < 0.001). Despite the shorter evacuation time interval of two hours, the 600 microg dose was associated with an increase in side effects such as vaginal bleeding, abdominal pain and a fever of > 38.0 degrees C. However, other than abdominal pain, no significant differences in the frequency of these side effects were shown. CONCLUSION: Use of 400 microg misoprostol with a minimal evacuation time interval of three hours still appears the optimal dosage and evacuation time for cervical priming before first trimester termination of pregnancy.

Abortifacient Agents, Nonsteroidal↗
PubMed1998

Randomized trial to determine optimal dose of vaginal misoprostol for preabortion cervical priming.

OBJECTIVE: To determine the optimal dosage of vaginal misoprostol for cervical priming before vacuum aspiration abortion. METHODS: One hundred twenty women were assigned randomly to receive 200, 400, 600, or 800 microg of misoprostol given vaginally. Vacuum aspiration was performed 3-4 hours after the insertion of misoprostol tablets. The degree of cervical dilation before operation was measured with a Hegar dilator. Preoperative and intraoperative blood loss and associated side effects also were assessed. RESULTS: Twenty-nine (96.7%) women in the 400-microg group and all in the 600-microg and 800-microg groups achieved cervical dilation of at least 8 mm. The success rate for the 200-microg group was only 23.3%, significantly less efficacious than the 400-microg dose (odds ratio 95.3; 95% confidence interval 10.9, 830.9; P < .001). There was no significant difference among the 400-, 600-, and 800-microg groups (P = .364) with respect to achieving cervical dilation at least 8 mm. However, 800 microg was associated with significantly more side effects than 600 microg (preoperative and intraoperative blood loss, P < .001; abdominal pain, P = .005; products of conception at os, P < .001; fever higher than 38.0C, P = .002). When 400 microg and 600 microg were compared, we found that the higher dose also was associated with significantly more side effects. The 600-microg group was used twice in the comparison, but all P values remained significant even after the Bonferroni adjustment for multiple comparisons. CONCLUSION: Vaginal application of 400 microg of misoprostol is the optimal dose for vacuum aspiration preabortion cervical dilation in first-trimester nulliparas.

Abortifacient Agents, Nonsteroidal↗
PubMed1998

Anaemia in pregnancy--a cross-sectional study in Singapore.

OBJECTIVE: To determine the prevalence and predictors of anaemia in pregnancy in Singapore. DESIGN: Hospital based case controlled study. SETTING: National University Hospital, between January-December 1993. SUBJECTS: All women delivered at the National University Hospital, Singapore in 1993 had their haemoglobin estimated. If it was less than 11 gm/dl, blood was taken to establish the cause of anaemia. Data was also collected with regard to their antenatal progress, and factors predisposing to anaemia in pregnancy. Logistic regression, Chi-square test, Fischer's exact test, Mantel-Haenszel test were used to assess the relationships between categorical variables. RESULTS: The prevalence of anaemia at delivery was 15.3%. The most common cause of anaemia in pregnancy was due to iron deficiency (81.3%). The occurrence of anaemia in pregnancy is related to the socio-economic status of the women. Multiparous women of the lower socio-economic class who tend to book late in pregnancy were found to have the highest risk of anaemia. Multivariate logistic regression analysis revealed iron prophylaxis, haemoglobin level at booking, race and previous history of anaemia in earlier pregnancy as important predictors of anaemia at delivery. The odds of anaemia for a woman not on therapy was about 11 times that of her counterpart on prophylactic iron therapy (95% CI 8.76-14.13). A 55% reduction in odds of anaemia was estimated per 1 gm% increase in haemoglobin level at booking. As compared to Chinese, Malays and Indians who experienced significant increase in odds of anaemia of 95% and 58% respectively. Further, a pregnant woman with a previous history of anaemia is 2.6 times as likely to be anaemic, as compared with one without history of anaemia. Except for a higher incidence of preterm delivery, there was no other statistically increased risk of complications in the antepartum, intrapartum or postpartum periods. There was no difference in the incidence of antepartum haemorrhage/operative deliveries, postpartum haemorrhage, low birthweight, intrauterine growth retardation and neonatal outcome. CONCLUSIONS: The study confirms that iron deficiency anaemia is the most common cause of anaemia in pregnancy and is a major health problem in developing and developed countries.

Anemia↗
PubMed1998

Prophylactic oophorectomy: a continuing controversy.

Prophylactic oophorectomy remains a controversial issue among gynecological surgeons. A woman's history of hereditary ovarian cancer syndrome is currently considered the most important indication for prophylactic oophorectomy. This is because of the high risk of ovarian cancer developing in these women and the poor prognosis that is generally associated with ovarian cancer. The purpose of prophylactic oophorectomy in women with no family history of hereditary ovarian cancer syndrome who present for hysterectomy because of other gynecological indications is, however, less clear. The attitude of the patients toward removal of normal ovaries deserves special consideration when counseling for prophylactic oophorectomy in this group of women. Knowledge about the risk of ovarian cancer in the conserved ovaries, cancer phobia, possible psychological effects of prophylactic oophorectomy, and the need for long-term hormone replacement therapy if prophylactic oophorectomy is carried out, are all important considerations in the counseling process.

Female↗
PubMed1998

A comparative study using two dose regimens (200 microg or 400 microg) of vaginal misoprostol for pre-operative cervical dilatation in first trimester nulliparae.

OBJECTIVE: To determine the optimal dosage and dosing interval for the use of misoprostol administered vaginally for pre-operative cervical dilatation. DESIGN: Prospective double-blind randomised study. SETTING: Fertility Control Centre, National University Hospital, Singapore. METHODS: Women were randomly allocated to either the 200 microg or the 400 microg misoprostol group. Vacuum aspiration was performed at either three or four hours after the insertion of misoprostol tablets. Using Hegar's dilatator, degree of cervical dilatation before operation was measured. Other parameters assessed included the amount of additional dilatation required (if it was < Hegar 8), pre-operative and intra-operative blood loss, and associated side effects. RESULTS: For the 200 microg misoprostol group, only seven (23.3%) achieved a dilatation of > or = 8 mm compared with 29 women (96.7%) in the 400 microg misoprostol group. The odds ratio was 95.3 (95% CI 10.9-830.9) for 400 microg misoprostol for successful pre-operative cervical dilatation of > or = 8 mm. The mean cervical dilatation for 400 microg and 200 microg misoprostol was 8.2 mm and 6.4 mm, respectively (P < 0.001). The use of 400 microg misoprostol with an evacuation interval of three hours appears to be the optimal dosage and evacuation time interval. Increasing the time interval beyond three hours did not confer any additional advantage on the rate of successful cervical dilatation but was instead associated with an increase in side effects such as vaginal bleeding, lower abdominal pain and the appearance of products of conception at the cervical os. However, besides vaginal bleeding, no significant differences in the frequency of these side effects were demonstrated. CONCLUSION: This first report on the comparison of differing dosages and time intervals to determine the optimal dosage treatment schedule shows that the vaginal application of 400 microg misoprostol for at least three hours is optimal for pre-operative cervical dilatation before vacuum aspiration in first trimester nulliparae.

Abdominal Pain↗
PubMed1998

A comparison between intravenous iron polymaltose complex (Ferrum Hausmann) and oral ferrous fumarate in the treatment of iron deficiency anaemia in pregnancy.

Anaemia is the most common medical disorder in pregnancy with iron deficiency anaemia accounting for the majority of cases. Over 90% of the iron deficiency anaemia is due to red cell iron deficiency associated with depleted iron stores and deficient intake. The two main modalities of treating iron deficiency anaemia are oral or parenteral iron. Ferrous Hausmann (iron dextrin) is the latest iron preparation which can be used for intravenous parenteral administration as a total dose infusion. This study compares the efficacy of Ferrum Hausmann with oral ferrous fumarate therapy in the treatment of iron deficiency anaemia in pregnancy. Our study shows that treatment with intravenous Ferrum Hausmann (iron dextrin) resulted in a significantly better level and rate of increase of haemoglobin (p<0.001). Serum ferritin, which is the best indicator of iron stores, was significantly higher (p<0.001) in the intravenous group. Other indices of iron status such as serum iron, serum transferrin and zinc protoporphyrin also showed a significant improvement in the intravenous group compared to those given oral iron. The results suggest that intravenous iron as a total dose infusion is able to replenish iron stores more efficiently, completely and at a faster rate than oral iron therapy, thus providing the fuel for stimulation of full erythopoiesis compared to oral iron. There were also no reports of any adverse reactions with intravenous iron dextrin, whereas there were a considerable proportion of women on oral iron therapy who reported side effects. In conclusion, intravenous iron therapy with Ferrous Hausmann (iron dextrin) is a suitable, effective and safe alternative to oral iron therapy in the treatment of iron deficiency anaemia in pregnancy.

Administration, Oral↗