J S Clewes

University of Nottingham, Nottigham, England, United Kingdom

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Publications (63)223.57 Total impact

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    ABSTRACT: This study evaluated whether 3D power Doppler (3DPD) indices from endometrium and subendometrium can identify increases in endometrial volume/vascularity induced by exogenous oestradiol and subsequent introduction of progestogens in women undergoing frozen–thawed embryo transfer (FET). Oral oestradiol was administered at increasing doses after down-regulation to prepare the endometrium and progestogens were used for luteal support. 3DPD data sets were acquired at down-regulation, on days 5, 10 and 15 of oestradiol administration and at the time of FET. Endometrial thickness was measured using the multiplanar method and endometrial volume and blood flow from the endometrium and subendometrium were estimated using virtual organ computer-aided analysis and shell-imaging. This study evaluated 45 women at least once: 19 achieved clinical pregnancy (CP); 21 were evaluated at down-regulation (eight CP), 26 at day 5 (10 CP), 31 at day 10 (12 CP), 31 at day 15 (13 CP) and 16 at FET (seven CP). Changes were observed in all parameters between the examinations; however, differences between women who achieved CP and those who did not were not significant. 3DPD angiography is not a sufficiently sensitive tool to predict the outcome of FET. We evaluate whether 3D ultrasound using power Doppler (3DPD) indices from endometrium and subendometrium can identify predictable increases in endometrial volume and vascularity induced by serial increments in exogenous oestradiol and the subsequent introduction of progestogens in women undergoing frozen–thawed embryo transfer (FET) using hormone replacement therapy to prepare the endometrium. Oral oestradiol was administered at increasing doses after down-regulation to prepare the endometrium and progestogens were used for luteal support. 3DPD data sets of the uterus were acquired at down-regulation, on days 5, 10, and 15 of oestradiol administration, and at the time of FET. Endometrial thickness was measured. Endometrial volume and blood flow from the endometrium and subendometrium were measured using virtual organ computer-aided analysis (VOCAL) and shell imaging. This study evaluated 45 women at least once: 19 achieved clinical pregnancy (CP); 21 were evaluated at down-regulation (eight CP), 26 at day 5 (10 CP), 31 at day 10 (12 CP), 31 at day 15 (13 CP) and 16 at FET (seven CP). Changes were observed in all the parameters between the examinations; however, differences between women who achieved CP and those who did not were not significant, suggesting that quantitative 3D power Doppler angiography is not a sufficiently sensitive tool to predict the outcome of FET treatment.
    Reproductive biomedicine online 01/2013; · 2.68 Impact Factor
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    ABSTRACT: Objective: To quantify the intra-cyclical variation in markers of ovarian reserve measured by the antral follicle counts stratified by size using three-dimensional (3D) ultrasound and anti-Müllerian hormone (AMH) in women with normal menstrual cycles. Methods: Healthy volunteers with normal menstrual cycles were prospectively recruited. 3D ultrasound scan and blood test in early (F1) and mid follicular (F2) phase, peri-ovulatory (PO) and luteal (LU) phases of one menstrual cycle were performed. Antral follicles were measured using "sonography based automated volume calculation" with post processing (SonoAVC) and ovarian volume using Virtual Organ Computer-aided AnaLysis (VOCAL). Blood serum was processed for hormonal assays including AMH, Follicle stimulating hormone (FSH), Luteinising hormone (LH) and Oestradiol. Repeated measures analysis was used to examine the variance in markers of ovarian reserve in different phases of one menstrual cycle. Results: 36 volunteers were included in final analysis, of which 34 attended all four visits. Repeated measures analysis showed a significant variation in total antral follicle count (AFC) (P<0.001). However, on stratifying the antral follicles according to size using, a non-significant variation (P=0.382) was seen in small AFC (≤ 6mm) and a significant variation (P<0.001) in large AFC (>6mm). The ovarian volume showed a significant intra-cyclical variation (P<0.001). A small but significant intra-cyclical variation was noted in AMH levels (P=0.041). A significant variation was seen in levels of serum FSH, LH, and oestradiol (P<0.05). Conclusion: Small antral follicles (≤6.0mm) measured using 3D ultrasound and AMH show little intra-cycle variation and perhaps should be evaluated in prediction of ovarian reserve independent of menstrual cycle. Copyright © 2012 ISUOG. Published by John Wiley & Sons, Ltd.
    Ultrasound in Obstetrics and Gynecology 06/2012; · 3.56 Impact Factor
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    Ultrasound in Obstetrics and Gynecology 04/2012; 39(4):485-6. · 3.56 Impact Factor
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    ABSTRACT: Oral contraceptive pills suppress the hypothalomo-pituitary axis, which can affect the ultrasound and endocrine markers used to examine ovarian reserve. The objective of this study was to quantify the ultrasound and endocrine markers of functional ovarian reserve in women using a combined oral contraceptive pill (COCP) for more than a year. This was a prospective case-control study involving healthy volunteers: 34 women using for more than a year a COCP with hormone-free interval (HFI) were compared to 36 normo-ovulatory, age-matched controls who had not used hormonal contraception within the last year. Volunteers using a COCP underwent a 3D ultrasound examination and had a blood sample taken within the first 4 days of active pill ingestion and those in the control group had the scan and blood test in the early follicular phase (days 2-5) of menstrual cycle. The main outcome measure was the difference in antral follicle counts stratified according to size and anti-Müllerian hormone (AMH), follicle-stimulating hormone (FSH), luteinizing hormone (LH) and estradiol (E2) levels. There were no significant differences in the number of small antral follicles measuring 2-6 mm. The COCP group had significantly fewer antral follicles measuring ≥ 6 mm (P < 0.001) and had significantly smaller ovaries (P < 0.001), which also had lower vascular indices than the control group (P < 0.05). While serum FSH, LH and E2 levels were significantly lower in the COCP group (P < 0.05), there was no significant difference in serum AMH levels between the two groups. Prolonged use of COCP suppressed pituitary gonadotropins and antral follicle development beyond 6 mm, but had no effect on levels of serum AMH and number of small antral follicles.
    Ultrasound in Obstetrics and Gynecology 10/2011; 39(5):574-80. · 3.56 Impact Factor
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    Ultrasound in Obstetrics and Gynecology 10/2011; 38(S1). · 3.56 Impact Factor
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    Ultrasound in Obstetrics and Gynecology 10/2011; 38(S1). · 3.56 Impact Factor
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    Ultrasound in Obstetrics and Gynecology 10/2011; 38(S1). · 3.56 Impact Factor
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    Ultrasound in Obstetrics and Gynecology 10/2011; 38(S1). · 3.56 Impact Factor
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    Ultrasound in Obstetrics and Gynecology 10/2011; 38(S1). · 3.56 Impact Factor
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    Ultrasound in Obstetrics and Gynecology 10/2011; 38(S1). · 3.56 Impact Factor
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    ABSTRACT: To compare the reliability of our recently introduced technique for first-trimester embryo volume measurement, the 'semiautomated technique' using both Virtual Organ Computer-aided AnaLysis (VOCAL(™) ) and Sonography-based Automated Volume Count (SonoAVC) with a manual technique using VOCAL alone. Seventy-four subjects with viable, singleton first-trimester in-vitro fertilization (IVF) pregnancies were recruited. Each subject underwent transvaginal sonography, at which a three-dimensional ultrasound dataset of the entire gestational sac was acquired. Each embryo volume was measured by two techniques, each performed twice. In the semiautomated technique VOCAL was used to calculate the volume of the gestational and yolk sacs, and SonoAVC was used to quantify the fluid volume within the amniotic and extra-amniotic cavities. Embryo volume was calculated by subtracting the sum of yolk sac, amniotic and extra-amniotic fluid volumes from gestational sac volume. In the manual technique, VOCAL was used to delineate the entire embryo using 9° rotations. Reliability was assessed using limits of agreement and intraclass correlation coefficient. Datasets were included from 52 eligible subjects. Median gestational age was 7 + 4 weeks; median crown-rump length (CRL) was 13 (range, 2-29) mm; and median embryo volume was 1.8 (range, 0.03-8.1) cm(3) using the semiautomated technique and 0.7 (range 0.009-3.6) cm(3) using the manual technique. There was a significant discrepancy in the volumes measured by the two different techniques. Assessment of the limits of agreement suggested that the semiautomated technique (-15.8% to 14.0% of the mean embryo volume) was more reliable than was the manual technique (-22.4% to 26.6%). The semiautomated technique is more reliable than is the manual technique for embryo volume measurement. However, the discrepancy in measurements between the two methods raises concerns over the validity of the semiautomated technique that require further investigation.
    Ultrasound in Obstetrics and Gynecology 07/2011; 38(5):516-23. · 3.56 Impact Factor
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    ABSTRACT: To estimate the prevalence of congenital uterine anomalies in subfertile women and to evaluate their influence on early pregnancy following assisted reproduction treatment (ART). We prospectively recruited 1402 subjects undergoing ART over a period of 5 years from 2005 to 2009. Three-dimensional transvaginal sonography was performed in the early follicular phase of the menstrual cycle (days 2-5) and repeated in the late follicular phase (days 10-14) if the shape of the uterine cavity could not be assessed at the first scan. All subjects who conceived following ART were followed up to 12 weeks' gestation. Chi-square test was used to compare the pregnancy rates and miscarriage rates between women shown to have uterine anomalies and those with a normal uterus. One thousand three hundred and eighty-five subjects were included for final analysis after excluding 17 subjects in whom a definitive diagnosis could not be made. While 1201 (86.7%) subjects had a normal uterine cavity, uterine anomalies were demonstrated in 184 (13.3%) subjects. Arcuate uteri represented the commonest anomaly (n = 164 (11.8%)) followed by septate (n = 7 (0.5%)), unicornuate (n = 6 (0.4%)), subseptate (n = 5 (0.4%)), bicornuate (n = 1 (0.1%)) and T-shaped uteri (n = 1 (0.1%)). A total of 440 subjects who underwent ART were followed up. The pregnancy rates in women with arcuate uteri (36/66 (54.5%)) and major uterine anomalies (7/10 (70.0%)) were statistically similar (P = 0.09 and P = 0.11, respectively) to that of the matched controls with normal uteri (158/364 (43.4%)). While first-trimester miscarriage rates were similar (P = 0.81) between the control group (20/158 (12.7%)) and women with arcuate uteri (5/36 (13.9%)), women with major uterine anomalies experienced a higher miscarriage rate (3/7 (42.9%); P = 0.05). Women who are referred for ART have a high prevalence of congenital uterine anomalies, the most common anomaly being an arcuate uterus. These anomalies are not associated with a reduction in pregnancy rates following ART. However, while the arcuate uterus was not associated with an increase in first-trimester miscarriage, major uterine anomalies seemed to increase the risk of first-trimester miscarriage.
    Ultrasound in Obstetrics and Gynecology 02/2011; 37(6):727-32. · 3.56 Impact Factor
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    ABSTRACT: To evaluate differences in the three-dimensional (3D) ultrasound markers of ovarian reserve between the ovaries within an individual undergoing investigation for subfertility. Prospective observational study. University-based assisted conception unit. Two hundred seventy women undergoing baseline early follicular phase ultrasound as an investigation for subfertility. Three-dimensional ultrasound scan in early follicular phase between days 2 and 5 of the menstrual cycle. Variations in 3D ultrasound markers of ovarian reserve between the two ovaries within same individual. Two hundred fifteen subjects were analyzed for ovarian volume and antral follicle count, and 205 subjects for 3D power Doppler indices. Significant differences were noted (median, range) in the number of antral follicles measuring >6.0 mm and ovarian volume. Significant correlation was noted between the two ovaries in antral follicles measuring 6.0 mm or less, ovarian volume, and 3D power Doppler indices. On stratifying the antral follicles according to size using sonography-based automated volume calculation with postprocessing, maximum variation was seen in follicles measuring more than 6.0 mm as measured using limits of agreement. There are significant differences in the antral follicles measuring >6.0 mm and ovarian volume, as measured using 3D ultrasound, that require consideration when comparing the two ovaries within an individual.
    Fertility and sterility 10/2010; 95(2):667-72. · 3.97 Impact Factor
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    Ultrasound in Obstetrics and Gynecology 10/2010; 36(S1):24-25. · 3.56 Impact Factor
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    S Sur, J Clewes, N Raine-Fenning
    Ultrasound in Obstetrics and Gynecology 10/2010; 36(S1):6-7. · 3.56 Impact Factor
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    Ultrasound in Obstetrics and Gynecology 10/2010; 36(S1):25-26. · 3.56 Impact Factor
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    Ultrasound in Obstetrics and Gynecology 10/2010; 36(S1):228. · 3.56 Impact Factor
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    Ultrasound in Obstetrics and Gynecology 10/2010; 36(S1):25. · 3.56 Impact Factor
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    Ultrasound in Obstetrics and Gynecology 10/2010; 36(S1):97. · 3.56 Impact Factor
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    ABSTRACT: The aim was to assess intraobserver reliability of a new semi-automated technique of embryo volumetry. Power calculations suggested 46 subjects with viable, singleton pregnancies were required for reliability analysis. Crown rump length (CRL) of each embryo was analyzed using 2-D and a 3-D dataset acquired using transvaginal ultrasound. Virtual organ computer-aided analysis (VOCAL) was used to calculate volume of gestation sac (GSV) and yolk sac (YSV) and SonoAVC (sonography-based automated volume count) was used to quantify fluid volume (FV). Embryo volume was calculated by subtracting FV and YSV from GSV. Each dataset was measured twice. Reliability was assessed using Bland-Altman plots and intraclass correlation coefficients (ICCs). Fifty-two datasets were analyzed. Median embryo volume was 1.8 cm(3) (0.1 to 8.1 cm(3)); median gestational age 7 + 4 weeks; median CRL 13 mm (2 to 29 mm). Mean difference of embryo volume measurements was 0.1cm(3) (limits of agreement [LOA] -0.3 to 0.4 cm(3)); multiples of mean (MoM) 0.38; mean difference of CRL measurements 0.3 mm (LOA -1.4 to 2.0 mm), MoM = 0.26. ICC for embryo volume was 0.999 (95%CI 0.998 to 0.999), confirming excellent intraobserver agreement. ICC for CRL was 0.996 (95%CI 0.991 to 0.998). Regression analysis showed good correlation between embryo volume and CRL (R(2) = 0.60). The new semi-automated 3-D technique provides reliable measures of embryo volume. Further work is required to assess the validity of this technique.
    Ultrasound in medicine & biology 04/2010; 36(5):719-25. · 2.46 Impact Factor

Publication Stats

883 Citations
223.57 Total Impact Points

Institutions

  • 2003–2013
    • University of Nottingham
      • • Division of Obstetrics and Gynaecology
      • • School of Clinical Sciences
      Nottigham, England, United Kingdom
  • 2007–2010
    • Nottingham University Hospitals NHS Trust
      • Department of Obstetrics and Gynaecology
      Nottigham, England, United Kingdom