Christine M.Y. Choy

The Chinese University of Hong Kong, Hong Kong, Hong Kong

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Publications (6)19.72 Total impact

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    ABSTRACT: To compare blood mercury concentrations of infertile couples with those of fertile couples in Hong Kong, and to examine the relationship between blood mercury concentrations and seafood consumption. Case-control study. In vitro fertilisation (IVF) Unit and Antenatal Unit of a university teaching hospital. Sample One hundred fifty-seven infertile couples attending IVF treatment and 26 fertile couples attending antenatal care without known occupational exposure to mercury. Mercury concentrations in whole blood were measured by cold vapour atomic absorption spectrophotometry. A dietitian recorded the quantity of seafood consumption among infertile couples via a food-frequency questionnaire. Blood mercury concentrations and quantity of seafood consumption were compared between infertile and fertile couples. Whole blood mercury concentrations, quantity of seafood consumption. Infertile couples had higher blood mercury concentrations than fertile couples. 'Infertile males with abnormal semen' and 'infertile females with unexplained infertility' also had higher blood mercury concentrations than their fertile counterparts. Blood mercury concentrations were positively correlated with quantity of seafood consumption. Infertile subjects with elevated blood mercury concentrations consumed a larger amount of seafood. Higher blood mercury concentration is associated with male and female infertility. Higher seafood consumption is associated with elevated blood mercury concentrations in our infertile population.
    BJOG An International Journal of Obstetrics & Gynaecology 11/2002; 109(10):1121-5. DOI:10.1016/S1470-0328(02)02984-1 · 3.45 Impact Factor
  • Fertility and Sterility 09/2002; 78(2):426-8. DOI:10.1016/S0015-0282(02)03232-6 · 4.59 Impact Factor
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    C M Y Choy · W H Tam · T N Leung
    BJOG An International Journal of Obstetrics & Gynaecology 08/2002; 109(7):847-8. DOI:10.1111/j.1471-0528.2002.01041.x · 3.45 Impact Factor
  • P M Lam · L P Cheung · C M Y Choy · Y P Lau · C Haines
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    ABSTRACT: Gonadotropin releasing hormone agonists (GnRHa) are commonly used during in vitro fertilization and embryo transfer (IVF/ET) treatment cycles to downregulate the hypothalamic-pituitary-ovarian axis prior to ovarian stimulation with gonadotropins. It has been suggested that profound downregulation may have an adverse effect on IVF/ET outcome. The aim of this study was to examine the relationship between the degree of downregulation and IVF/ET outcome. A retrospective analysis was performed on 151 IVF/ET cycles conducted over a six month period. Intensity of downregulation was assessed using measurements of serum concentrations of luteinizing hormone (LH) and estradiol (E2) made at the end of a two week downregulation period. There was no correlation between serum concentration of LH (whether used alone or in combination with E2) and IVF/ET pregnancy rates. However, those subjects who were more suppressed according to the E2 concentration (< 148 pmol/l, [median]) required significantly more gonadotropins (3306 IU versus 2863 IU, p < 0.05) and took longer for follicles to reach maturity (10.9 days versus 9.7 days, p < 0.05). They also had a lower pregnancy rate per embryo transfer (10.4% versus 28.6%, p < 0.05) compared with those having a higher basal E2 concentration. We conclude from this study that the basal serum E2 concentration rather than the LH concentration is a more sensitive indicator of the intensity of downregulation by GnRHa and it may be a better predictor of IVF outcome.
    Gynecological Endocrinology 04/2002; 16(2):143-50. DOI:10.1080/713603034 · 1.33 Impact Factor
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    C.M.Y. Choy · W.C. Lau · W.H. Tam · P.M. Yuen
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    ABSTRACT: To compare the efficacy and safety of intravenous oxytocin with intramuscular syntometrine in the management of the third stage of labour. A prospective randomised trial. A university teaching hospital. A total of 991 women having a singleton pregnancy and vaginal delivery were randomised by a computer-generated number to receive either 1 ml syntometrine intramuscularly or 10 units of intravenous Syntocinon after delivery of the anterior shoulder of the fetus. Blood loss during delivery, rate of postpartum haemorrhage, need for repeated oxytocics, haemoglobin level before and 24 hours after delivery, duration of third stage, need for manual removal of placenta and sides effects including hypertension, nausea, vomiting, headache and chest pain. The use of intravenous oxytocin was associated with a reduction in postpartum blood loss (P < 0.001) but there was no difference in the risk of postpartum haemorrhage in the need for repeated oxytocic injections and the drop in peripartum haemoglobin level between the two groups. There was also no difference in the risk of prolonged third stage, or in the need for manual removal of placenta. The use of syntometrine was associated with a higher risk of hypertension (RR 2.39, 95% CI 1.00-5.70). Other side effects were mild in nature with no differences between the two groups. There are no important clinical differences in the effectiveness of intramuscular syntometrine and intravenous oxytocin for the prevention of postpartum blood loss. Intravenous oxytocin is less likely to cause hypertension.
    BJOG An International Journal of Obstetrics & Gynaecology 02/2002; 109(2):173-7. DOI:10.1111/j.1471-0528.2002.01204.x · 3.45 Impact Factor
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    C.M.Y Choy · W H Tam · P C Ng
    BJOG An International Journal of Obstetrics & Gynaecology 01/2002; 108(12):1298-9. DOI:10.1016/S0306-5456(01)00285-6 · 3.45 Impact Factor

Publication Stats

93 Citations
19.72 Total Impact Points


  • 2002
    • The Chinese University of Hong Kong
      • Department of Obstetrics and Gynaecology
      Hong Kong, Hong Kong
    • Prince of Wales Hospital, Hong Kong
      Chiu-lung, Kowloon City, Hong Kong