John Williams

University of California, Los Angeles, Los Ángeles, California, United States

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Publications (9)35.66 Total impact


  • No preview · Article · Jan 2013 · American Journal of Obstetrics and Gynecology
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    ABSTRACT: Real-time 4-dimensional (4D) sonography can visualize the location of a chorionic villus sampling (CVS) catheter simultaneously in 3 dimensions. We determined the utility of 4D versus 2-dimensional (2D) sonographic guidance for transcervical CVS. Chorionic villus sampling was performed on 40 patients at 10 to 13 weeks' gestation (20 in each study group). Primary outcomes were as follows: (1) time in seconds needed to complete the procedure; (2) procedure failure, defined as the inability to obtain an adequate sample by a single catheter insertion or a necessity to switch to the alternative imaging modality; and (3) acquisition of a sample of chorionic villi sufficient for cytogenetic analysis. Wilcoxon rank sum and Fisher exact tests were used for categorical and continuous variables, respectively. Figure 1. A, Two-dimensional guidance of the transcervical chorionic villus sampling procedure. Arrows indicate the chorionic villus sampling catheter. B, Multiplanar 3-dimensional guidance of the procedure. The procedure time was significantly longer in the 4D group than the 2D group (161.4 versus 80.4 seconds, respectively; P = .001). The success rate at first introduction of the catheter was higher for 2D guidance (90%) than 4D guidance (70%) but was not statistically significant with the study group sizes. Adequate sample sizes were obtained in all patients. The main limiting factor in 4D guidance was a low frame rate. Our findings show the feasibility of 4D guidance for transcervical CVS, although at the expense of a prolonged procedure time when compared to 2D sonographic guidance. The value of 4D guidance for less experienced operators remains to be determined.
    No preview · Article · Mar 2011 · Journal of ultrasound in medicine: official journal of the American Institute of Ultrasound in Medicine
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    ABSTRACT: Our investigation of differences in first-trimester placentation and/or fetal biometry in pregnancies conceived spontaneously compared with those conceived through fertility treatment, and comparing less invasive fertility treatment with in vitro fertilization found no statistically significant difference in first-trimester abnormal placentation or fetal growth between pregnancies conceived spontaneously and those conceived through fertility treatment, or between the in vivo and in vitro subgroups.
    No preview · Article · Dec 2010 · Fertility and sterility
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    ABSTRACT: To determine if pregnancies conceived through infertility treatment are at increased risk of cytogenetic abnormalities in the late first trimester compared with spontaneously conceived pregnancies, or if there is increased risk when comparing less invasive infertility treatment (in vivo group) to in vitro fertilization (in vitro group). Retrospective case-controlled study. University hospital. A total of 1,606 women who spontaneously conceived and 559 women who conceived through infertility treatment undergoing chorionic villus sampling (CVS). None. Cytogenetic abnormalities diagnosed by CVS. No difference in cytogenetic abnormalities was found when comparing spontaneously conceived pregnancies to those conceived through infertility treatment (7.0% versus 5.4%). We also found no difference in the prevalence of cytogenetic abnormalities when comparing in vivo and in vitro fertilization subgroups (4.7% versus 5.8%). Finally, no difference was found when comparing the prevalence of different types of cytogenetic abnormalities between groups. Infertility treatment does not increase the risk of carrying a cytogenetically abnormal fetus in the late first trimester, nor does it increase the preponderance for any specific type of abnormality.
    Full-text · Article · Oct 2010 · Fertility and sterility
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    ABSTRACT: The purpose of this study was to determine the association between discordant crown-rump length (CRL) measurements in structurally normal euploid dichorionic twins and adverse pregnancy outcomes. This retrospective cohort study included women with dichorionic twins who underwent chorionic villus sampling and delivered in our facility from January 2000 to September 2007. Only pregnancies with viable twin fetuses and normal karyotypes were included. The association between CRL discordance, defined as a CRL discrepancy of 9% or greater, and adverse pregnancy outcomes was evaluated. Seventy-eight women met inclusion criteria and included 24 discordant twins (group 1) and 54 concordant twins (group 2). Maternal ages were similar: mean ± SD, 38.2 ± 3.1 years in group 1 versus 39.2 ± 3.9 years in group 2 (P = not significant). The median gestational ages at delivery were 35.6 ± 3.1 weeks in group 1 and 37.3 ± 2.0 weeks in group 2 (P < .01). At least 1 major complication occurred in 19 women (79%) in group 1 and 25 (46%) in group 2 (P = .01). Group 1 had significantly more major complications overall (P = .0008). Preterm premature rupture of membranes occurred in 10 women (42%) in group 1 and 6 (11%) in group 2 (P = .005). Delivery before 37 weeks' gestation occurred in 19 of 24 women (79%) in group 1 and 24 of 54 (44%) in group 2 (P = .006). There was a significant difference for younger gestational age at delivery in the discordant group (P < .01). Our data suggest that there is an increased risk of adverse pregnancy outcomes in chromosomally normal dichorionic twins with first-trimester discordant CRL measurements. These results may be clinically useful for counseling, management, and antenatal surveillance.
    No preview · Article · Oct 2010 · Journal of ultrasound in medicine: official journal of the American Institute of Ultrasound in Medicine

  • No preview · Article · Dec 2008 · American Journal of Obstetrics and Gynecology
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    ABSTRACT: To determine if mosaicism that occurs in infertility and assisted reproductive technologies continues in the late first trimester and if this is unique to infertility or occurs in all pregnancies. Retrospective case-controlled study. University hospital. 5337 consecutive chorionic villus samplings (CVS). None. Mosaic karyotypes at CVS. We confirmed 69 mosaic karyotypes, a rate of 1.29%. Comparing spontaneous pregnancies with pregnancies from infertility treatment, no difference was found in the prevalence of mosaicism: 1.22% versus 1.32%, respectively. Subgroup analysis of infertile couples, comparing in vitro (assisted reproduction) with in vivo fertilization (other treatments) revealed a mosaicism rate of 1.84% and 0.41%, respectively. Confined placental mosaic (CPM) rates for infertility treated pregnancies and spontaneously conceived pregnancies were 0.88% and 0.92%, respectively. Subgroup analysis of infertile patients revealed a CPM rate of 1.15% for in vitro fertilization treatment and 0.41% for in vivo fertilization treatment. These results were not statistically significant. There was no difference in the prevalence of mosaicism at the end of the first trimester in pregnancies conceived spontaneously compared with those with infertility. There was no difference in the prevalence of mosaicism when in vitro and in vivo treatment were compared.
    No preview · Article · Jul 2008 · Fertility and sterility

  • No preview · Article · Dec 2007 · American Journal of Obstetrics and Gynecology
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    ABSTRACT: This study was undertaken to evaluate the relationship between chorionic villus sampling at 10-13 weeks' gestational age and hypertensive disorders of pregnancy. The prevalence of hypertensive disorders of pregnancy in women with singleton gestations, undergoing transcervical or transabdominal chorionic villus sampling between 10 weeks 0 days' and 13 weeks 6 days' gestational age was compared with that of control women with singleton gestations having first-trimester screening with nuchal translucency and biochemistry between 11 weeks 0 days' and 13 weeks 6 days' gestational age. Patients having invasive prenatal diagnosis (chorionic villus sampling or amniocentesis) were excluded from the control group. All patients delivered at Cedars-Sinai Medical Center. There were 1540 women who had chorionic villus sampling and 840 controls. Hypertensive disorders of pregnancy were diagnosed in 76 (4.9%) patients in the chorionic villus sampling group and in 37 (4.4%) of the controls (chi2 = 0.34, P = .31). Chorionic villus sampling at 10 to 13 weeks' gestational age does not appear to increase the overall risk for hypertensive disorders of pregnancy. However, there appears to be an association between chorionic villus sampling and severe hypertensive disorders including severe preeclampsia, eclampsia, and hemolysis, elevated liver enzymes, and low platelet count syndrome.
    No preview · Article · Jul 2007 · American journal of obstetrics and gynecology

Publication Stats

47 Citations
35.66 Total Impact Points

Institutions

  • 2008-2013
    • University of California, Los Angeles
      • Department of Obstetrics and Gynecology
      Los Ángeles, California, United States
  • 2007-2011
    • Cedars-Sinai Medical Center
      • Cedars Sinai Medical Center
      Los Ángeles, California, United States