Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Jiri Sonek is active.

Publication


Featured researches published by Jiri Sonek.


The Lancet | 2001

Absence of nasal bone in fetuses with trisomy 21 at 11-14 weeks of gestation: an observational study.

S. Cicero; Patrizia Curcio; A. T. Papageorghiou; Jiri Sonek; Kypros H. Nicolaides

BACKGROUNDnPrenatal diagnosis of trisomy 21 requires an invasive test in women regarded as being at high risk after screening. At present there are four screening tests, and for a 5% false-positive rate, the sensitivities are about 30% for maternal age alone, 60-70% for maternal age and second-trimester maternal serum biochemical testing, 75% for maternal age and first-trimester fetal nuchal translucency scanning, and 85% for maternal age with fetal nuchal translucency and maternal serum biochemistry at 11-14 weeks. In this study, we examined the possible improvement in screening for trisomy 21 by examining the fetal nasal bone with ultrasound at 11-14 weeks of gestation.nnnMETHODSnWe did an ultrasound examination of the fetal profile in 701 fetuses at 11-14 weeks gestation immediately before karyotyping for a possible chromosomal abnormality detected by maternal age and fetal nuchal translucency screening. The presence or absence of a nasal bone was noted.nnnFINDINGSnThe fetal profile was successfully examined in all cases. The nasal bone was absent in 43 of 59 (73%) trisomy 21 fetuses and in three of 603 (0.5%) chromosomally normal fetuses. The likelihood ratio for trisomy 21 was 146 (95% CI 50-434) for absent nasal bone and 0.27 (0.18-0.40) for present nasal bone. In screening for trisomy 21, by a combination of maternal age and fetal nuchal translucency, we estimated that inclusion of examination of the fetal profile for the presence or absence of nasal bone could increase the sensitivity to 85% and decrease the false-positive rate to about 1%.nnnINTERPRETATIONnIn screening for trisomy 21, examination of the fetal nasal bone could result in major reduction in the need for invasive testing and a substantial increase in sensitivity.


Ultrasound in Obstetrics & Gynecology | 2003

Nasal bone hypoplasia in trisomy 21 at 15-22 weeks' gestation.

S. Cicero; Jiri Sonek; David McKenna; Christopher S. Croom; L. Johnson; Kypros H. Nicolaides

To investigate the potential value of ultrasound examination of the fetal profile for present/hypoplastic fetal nasal bone at 15–22 weeks gestation as a marker for trisomy 21.


Ultrasound in Obstetrics & Gynecology | 2003

Nasal bone length throughout gestation: normal ranges based on 3537 fetal ultrasound measurements

Jiri Sonek; David McKenna; D Webb; Christopher S. Croom; Kypros H. Nicolaides

To establish normal ranges for nasal bone length measurements throughout gestation and to compare measurements in two subsets of patients of different race (African‐American vs. Caucasian) to determine whether a different normal range should be used in these populations.


Ultrasound in Obstetrics & Gynecology | 2004

Maxillary length at 11-14 weeks of gestation in fetuses with trisomy 21

S. Cicero; P Curcio; G. Rembouskos; Jiri Sonek; Kypros H. Nicolaides

To determine the value of measuring maxillary length at 11–14 weeks of gestation in screening for trisomy 21.


American Journal of Perinatology | 2011

A Randomized Trial of Micronized Progesterone for the Prevention of Recurrent Preterm Birth

Melanie Glover; David McKenna; Cathy Downing; Dana B Smith; Christopher S. Croom; Jiri Sonek

We sought to evaluate the effectiveness of daily oral micronized progesterone (MP) in preventing recurrent spontaneous preterm birth (RSPB) and whether MP increases maternal serum progesterone. We performed a pilot, single-center, randomized, double-blind, placebo-controlled trial in women with a prior preterm birth and current singleton gestation at 16 to 20 weeks ( N = 33). The primary outcome was the rate of RSPB. Subjects were given either daily MP (400 mg) or placebo from 16 to 34 weeks. Serum progesterone was obtained at enrollment and in the late second/early third trimester. Pregnancy outcome data were collected. RSPB occurred in 5/19 (26.3%) in the MP group versus 8/14 (57.1%) in placebo group ( P = 0.15). The mean age at delivery was 37.0 ± 2.7 weeks for the MP group versus 35.9 ± 2.6 weeks for the placebo ( P = 0.3). Mean serum progesterone at 28 weeks was 122.6 ± 61.8 pg/mL for MP group versus 90.1 ± 38.7 pg/mL for placebo ( P = 0.19). MP was associated with a trend toward a reduction in RSPB and an increase in the maternal serum progesterone. Although the primary outcome in this pilot study did not reach statistical significance, the results suggest a favorable trend meriting further investigation.


Diabetes | 1991

Sonographic Measurement of Fetal Humeral Soft Tissue Thickness in Pregnancy Complicated by GDM

Mark B. Landon; Jiri Sonek; Pamela Foy; Lisa Hamilton; Steven G. Gabbe

Sonographic measurement of fetal humeral soft tissue thickness (STT) was performed in 93 women with gestational diabetes mellitus during the third trimester. STT measurements revealed accelerated growth in large for gestational age infants at 31 wk gestation. This new measurement proved to be the most accurate predictor of excessive fetal size compared with other standard ultrasound parameters (sensitivity 82%, specificity 95%, positive predictive value 90%). Asymmetrical growth was more evident in infants with large STT measurements in utero. Humeral STT measurement may distinguish large fetuses with truncal obesity from those that are symmetrically large, thereby allowing prediction of risk for birth trauma before delivery.


American Journal of Perinatology | 2008

Serial sonographic growth assessment in pregnancies complicated by an isolated single umbilical artery.

Samantha Wiegand; David McKenna; Christopher S. Croom; Gary Ventolini; Jiri Sonek; Ran Neiger

Pregnancies complicated by an isolated single umbilical artery (SUA) are thought to be at increased risk for intrauterine growth restriction (IUGR). The management of these pregnancies often includes serial sonographic assessments of fetal growth. The goal of our study was to test the validity of this assertion. We conducted a longitudinal sonographic assessment of intrauterine fetal growth in pregnancies complicated by a SUA. We included pregnancies where fetal growth was assessed three or more times, and the presence of SUA was repeatedly demonstrated. Pregnancies with fetal anomalies and multiple gestations were excluded. IUGR was defined as an estimated fetal weight (EFW) < or = 10th percentile of the normal ranges established by Hadlock. Between January 1999 and December 2005, we identified 273 pregnancies with SUA, for an overall incidence of 0.48% within the total population of patients examined at our institution. One hundred and thirty-five pregnancies did not meet our inclusion criteria. Of the 138 we analyzed, four pregnancies (2.9%) were found to have EFW < or = 10th percentile. We concluded that the occurrence of IUGR in pregnancies complicated by an isolated SUA is not increased. Serial sonographic assessments of fetal growth do not appear to be indicated in the management of such pregnancies.


American Journal of Obstetrics and Gynecology | 1990

Antenatal diagnosis of sacral agenesis syndrome in a pregnancy complicated by diabetes mellitus

Jiri Sonek; Steven G. Gabbe; Mark B. Landon; Laurence E. Stempel; Michael R. Foley; K. Shubert-Moell

The sacral agenesis syndrome is a severe congenital abnormality consisting of agenesis of the lumbar spine, sacrum, and coccyx, as well as hypoplasia of the lower extremities. It is considered the most characteristic of all congenital anomalies associated with maternal diabetes mellitus. We describe the sonographic and radiologic findings of agenesis of the lumbosacrococcygeal spine with lower limb and genital hypoplasia in the offspring of a woman with both diabetic retinopathy and nephropathy. The diagnosis was established at 25 weeks gestation and was confirmed by radiologic evaluation of the neonate.


American Journal of Obstetrics and Gynecology | 1987

Spontaneous rupture of uteroovarian veins in pregnancy: two case reports

Michael R. Foley; Jiri Sonek; L.Michael Lavender; Frederick P. Zuspan

Two cases of acute spontaneous rupture of uterine ovarian veins during the third trimester of pregnancy are reported. This condition has an obscure etiology and a relatively infrequent incidence and has been associated in the past with very high maternal and fetal mortality. The clinician is faced with both a puzzling diagnostic dilemma and a perplexing management scheme.


American Journal of Obstetrics and Gynecology | 1991

Morphologie changes in the human amnion epithelium that accompany labor as seen with scanning and transmission electron microscopy

Jiri Sonek; Steven G. Gabbe; Jay D. Iams; Douglas A. Kniss

Scanning and transmission electron microscopy were used to assess the influence of normal, active labor on the ultrastructure of the human amnion epithelial membrane. Amnion membranes (reflected and placental portions) were obtained from patients either in active labor who were delivered vaginally or by cesarean section after 6 to 12 hours of labor or from patients who underwent elective cesarean section before clinical signs of overt labor. Scanning electron microscopy revealed that reflected amnion membranes that were obtained from patients who were not in labor consisted of a uniform single layer of epithelial cells with numerous microvilli on the apical surface and closely associated cellular borders. In contrast, amnion membranes that were obtained from patients who were in labor consisted of a single layer of epithelial cells, which was interupted by wide intercellular gaps and extracellular extrusions. Transmission electron microscopy showed that intercellular junctions tended to be less complex in patients who were in labor versus patients who were not in labor. Although lipid droplets were prevalent in both patient groups, specimens that were obtained from patients who were in labor had more lipid droplets per cell than specimens from patients who were not in labor. These results support the theory that the complex biochemical events that culminate in parturition are accompanied and/or preceded by demonstrable morphologic changes in the amnion membrane.

Collaboration


Dive into the Jiri Sonek's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

S. Cicero

University of Cambridge

View shared research outputs
Top Co-Authors

Avatar

Jon Hyett

Royal Prince Alfred Hospital

View shared research outputs
Top Co-Authors

Avatar

Christine Kovac

Madigan Army Medical Center

View shared research outputs
Researchain Logo
Decentralizing Knowledge