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Dive into the research topics where Michal J. Simchen is active.

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Featured researches published by Michal J. Simchen.


Blood Cells Molecules and Diseases | 2003

Hematopoietic progenitor cells as targets for non-invasive prenatal diagnosis: detection of fetal CD34+ cells and assessment of post-delivery persistence in the maternal circulation.

E Guetta; D Gordon; Michal J. Simchen; B Goldman; Gad Barkai

Culture expansion of fetal cells from the maternal circulation will provide an increased number of cells for non-invasive prenatal diagnosis. Hematopoietic CD34+ cells are potential candidates for this application. More information is needed regarding the frequency of these cells and the phenomenon of post-delivery persistence in the maternal circulation. In this study we assessed the number of fetal CD34+ cells in the maternal circulation, the effect of culture expansion on the number of fetal cells and the persistence of fetal CD34+ cells from previous pregnancies. Fetal cells were identified by the presence of Y-chromosome sequences detected by FISH and nested PCR. Fetal CD34+ cells were detected in all samples from women carrying a male fetus. A low number of residual fetal cells from previous pregnancies was detected (1-3 XY cells in 20 ml blood) in less than 1/3 of the samples from both non-pregnant women and those pregnant with a female fetus. Culturing of CD34+ cells resulted in a significant increase in fetal cell numbers. However, the number of fetal cells persisting from previous pregnancies also increased after culture. It is proposed that information derived from CD34+ cells could potentially support data derived from other cell types for more accurate non-invasive prenatal diagnosis.


Stroke | 2009

Factor V Leiden and Antiphospholipid Antibodies in Either Mothers or Infants Increase the Risk for Perinatal Arterial Ischemic Stroke

Michal J. Simchen; Gal Goldstein; Aaron Lubetsky; Tzipi Strauss; Eyal Schiff; Gili Kenet

Background and Purpose— The objective was to investigate the role of infant and maternal thrombophilia in a cohort of mothers and infants presenting with perinatal arterial ischemic stroke. Methods— Forty-seven infants with clinically and radiologically confirmed perinatal arterial ischemic stroke underwent thrombophilia workup: factor V Leiden (FVL), PII20210A mutation, Methylene-tetrahydrofolate reductase 677T polymorphism, protein C, protein S, antithrombin, FVIII, and antiphospholipid antibodies. Thrombophilia data were available for 23 mother–infant pairs and compared with control populations to evaluate the risk for PAS. Results— Thirty of 47 (64%) infants and 15 of 22 mothers (68%) had evidence of thrombophilia. In 18 of 23 (78%) mother–infant pairs, there was at least 1 thrombophilic risk factor, but 15 pairs were mismatched in pathology. Among infants, FVL, protein C deficiency, and presence of antiphospholipid antibodies prevailed (OR, 4.2; 95% CI, 1.5–11.3; OR, 12.2; 95% CI, 2.5–59.9; OR, 4.1; 95% CI, 1.4–12.2, respectively). Interestingly FVL prevailed in almost one-third of mothers (OR, 8.5; 95% CI, 4.1–17.5) and 18% of mothers had antiphospholipid antibodies (OR, 3.8l; 95% CI, 1.5–10.0). Conclusions— Maternal and neonatal thrombophilia, especially presence of FVL or antiphospholipid antibodies, may be important in the pathogenesis of perinatal arterial ischemic stroke. The nature of thrombophilic mother–infant risk potential interactions warrants further investigation.


Acta Obstetricia et Gynecologica Scandinavica | 2012

Maternal and neonatal outcomes of large for gestational age pregnancies.

Alina Weissmann-Brenner; Michal J. Simchen; Eran Zilberberg; Anat Kalter; Boaz Weisz; Reuven Achiron; Mordechai Dulitzky

Objective. To compare maternal and neonatal outcomes of term large for gestational age (LGA) pregnancies and adequate for gestational age (AGA) pregnancies. Design. Retrospective analysis. Setting. Large university research medical center. Population. All term singleton LGA (birthweight ≥90th percentile) and AGA pregnancies (birthweight 10.1–89.9th percentile) delivering between 2004 and 2008. Methods. Data collected included maternal age, gestational age at delivery, mode of delivery, birthweight, fetal sex, and maternal and neonatal complications. Birthweight percentiles were determined according to locally derived gender‐specific birthweight tables. Main outcome measures. Comparisons between LGA and AGA pregnancies and between LGA 90–94.9th, 95–98.9th and ≥99th percentile. Results. The study population comprised 34 685 pregnancies; 3900 neonates matched the definition of term LGA. Maternal age and gestational age at delivery were significantly higher for LGA neonates. Significantly more LGA neonates were born by cesarean section, and significantly more LGA pregnancies were complicated by postpartum hemorrhage (PPH), shoulder dystocia or neonatal hypoglycemia, and had a longer hospitalization period. Maternal and neonatal risks increased as birthweight increased from the 90–94.9th to 95–98.9th to ≥99th percentile. Specifically, the risks of shoulder dystocia (odds ratio 2.61, 3.35 and 5.11, respectively), PPH (odds ratio 1.81, 2.12 and 3.92, respectively) and neonatal hypoglycemia (odds ratio 2.53, 3.8 and 5.19, respectively) all increased linearly with birthweight percentile. Conclusions. Large for gestational age pregnancies are associated with an increased rate of cesarean section, PPH, shoulder dystocia and neonatal hypoglycemia, as well as longer hospitalization. These risks increase as the birth percentile rises. These risks need to be emphasized in pre‐delivery counseling.


Human Reproduction | 2009

The aged uterus: multifetal pregnancy outcome after ovum donation in older women

Michal J. Simchen; Adrian Shulman; Amir Wiser; Eran Zilberberg; Eyal Schiff

BACKGROUNDnWe aimed to investigate whether multifetal pregnancies are at risk of more pregnancy complications in women of advanced age after ovum donation.nnnMETHODSnPregnancy outcome in women after ovum donation aged 40 and above was extracted. Labor and delivery data as well as antenatal records of women carrying twins were compared with those of singletons, as well as to a control group of all twin pregnancies delivered at Sheba Medical Center during 2007.nnnRESULTSnOne hundred and twenty-five women after ovum donation aged > or = 40 were studied. Of those, 42 women carried twin pregnancies and 83 carried singletons. The 42 women carrying twins comprised the study group and were compared with 417 control women with twins. Mean maternal age was 49.2 +/- 4.3 years. Hypertensive complications (50%), diabetes in pregnancy (31%) and hospitalization in pregnancy (69%) were all extremely high in the study group. Mean gestational age at delivery was lower for the study group compared with controls (35.2 +/- 2.3 versus 35.7 +/- 2.6 weeks), with 35.7% of infants in the study group born < or = 34 weeks gestation compared with 21.8% of controls, (OR: 1.99, 95% CI: 1.02-3.89). Mean birthweight was also significantly lower for study group infants compared with controls, with 77% of study infants born <2500 g compared with only 60% of controls (OR: 2.22, 95% CI: 1.3-3.77).nnnCONCLUSIONSnPregnancy in advanced maternal age women after ovum donation carrying twins is associated with significant maternal and fetal complications, with increased risks of prematurity and lower birthweight. Possibly, the aged uterus is less suitable for carrying a multifetal pregnancy than a younger uterus. Therefore, the alternative of transferring a single, good-quality embryo should be the preferred option.


Stem Cells and Development | 2004

Analysis of fetal blood cells in the maternal circulation: challenges, ongoing efforts, and potential solutions.

Esther Guetta; Michal J. Simchen; Keren Mammon-Daviko; Daphna Gordon; Ayala Aviram-Goldring; Nurit Rauchbach; Gad Barkai

The invasive procedures amniocentesis and chorionic villus sampling (CVS) are routinely applied in pregnancies at risk for fetal abnormalities and the results obtained are the gold standard for prenatal diagnosis. Because these methods of fetal cell procurement involve a 0.5-2% risk for fetal loss, they are recommended mainly in cases at high risk for fetal genetic or cytogenetic abnormalities. The development of a reproducible, reliable, noninvasive method based on retrieval of rare fetal cells from the maternal circulation will render testing feasible for the general population. Despite intensive investigation, a satisfactory, clinically acceptable method has not yet emerged. Several cell types have been targeted to this end, mostly nucleated red blood cells (NRBC), CD34+ hematopoietic progenitors, and trophoblasts. Although these cell types have been unequivocally proven to be present in the maternal circulation, each bears a significant disadvantage, rendering their application in clinical testing currently impossible: NRBC cannot be expanded in culture, thereby ruling out metaphase chromosome analysis, an essential component of prenatal diagnosis. CD34+ cells do posses the potential for in vitro proliferation, however, they have been found to persist in the maternal circulation after delivery, thereby complicating diagnosis in consecutive pregnancies. Trophoblasts are not consistently detected in the maternal circulation. Moreover, due to the lack of a definitive fetal cell marker and a reliable sorting method, foolproof fetal cell identification of any of these cell types is not possible. This report outlines the obstacles that impede development of a method for noninvasive fetal cell sampling for prenatal genetic diagnosis, along with a description of our efforts to analyze simultaneously two fetal blood cell types, NRBC and CD34+ cells in maternal blood during pregnancy, and the problems encountered. This work and that of others lead us to suggest potential future directions to help develop this important technique.


Prenatal Diagnosis | 2009

Isolated fetal umbilical vein varix—prenatal sonographic diagnosis and suggested management

Alina Weissmann-Brenner; Michal J. Simchen; Orit Moran; Eran Kassif; Reuven Achiron; Yaron Zalel

To present our experience with fetuses with umbilical vein varix (UVV), to investigate possible risk factors and to suggest a management scheme of evaluation.


Medical Science Monitor | 2012

Maternal and neonatal outcomes of macrosomic pregnancies

Alina Weissmann-Brenner; Michal J. Simchen; Eran Zilberberg; Anat Kalter; Boaz Weisz; Reuven Achiron; Mordechai Dulitzky

Summary Background To compare maternal and neonatal outcomes of term macrosomic and adequate for gestational age (AGA) pregnancies. Material/Methods A retrospective analysis was performed on all term singleton macrosomic (birth weight ≥4000 g) and AGA (birth weight >10th percentile and <4000 g) pregnancies delivered at our hospital between 2004 and 2008. Data collected included maternal age, gestational age at delivery, mode of delivery, birth weight, fetal gender, maternal and neonatal complications. Comparisons were made between macrosomic and AGA pregnancies and between different severities of macrosomia (4000–4250 g, 4250–4500 g and ≥4500 g). Results The study population comprised of 34,685 pregnancies. 2077 neonates had birth weight ≥4000 g. Maternal age and gestational age at delivery were significantly higher for macrosomic neonates. Significantly more macrosomic neonates were born by cesarean section, and were complicated with shoulder dystocia, neonatal hypoglycemia, and had longer hospitalization period (both in vaginal and cesarean deliveries). Specifically, the odds ratio (OR) relative to AGA pregnancies for each macrosomic category (4000–4250 g, 4250–4500 g and ≥4500 g) of shoulder dystocia was 2.37, 2.24, 7.61, respectively, and for neonatal hypoglycemia 4.24, 4.41, 4.15, respectively. The risk of post partum hemorrhage was statistically increased when birth weight was >4500 g (OR=5.23) but not for birth weight between 4000–4500 g. No differences were found in the rates of extensive perineal lacerations between AGA and the different macrosomic groups. Conclusions Macrosomia is associated with increased rate of cesarean section, shoulder dystocia, neonatal hypoglycemia, and longer hospitalization, but not associated with excessive perineal tears. Increased risk of PPH was found in the >4500g group.


Prenatal Diagnosis | 2001

Fetal hemoglobin‐expressing nucleated red blood cell frequencies in pregnancies with intrauterine growth restriction

Michal J. Simchen; Gad Barkai; Ayala Lusky; Esther Guetta

The objective of this study was to examine whether there is a difference in the frequency of fetal erythroblasts in maternal blood in pregnancies with intrauterine growth restriction (IUGR) as compared with normal pregnancies. Nucleated red blood cells (NRBC) were isolated from nine pregnant women with ultrasonically diagnosed IUGR (estimated fetal weight less than the 10th percentile for gestational age) and 11 women with appropriately grown fetuses. The frequency of fetal hemoglobin‐expressing NRBC (FHE‐NRBC) in maternal blood was evaluated by triple density centrifugation and anti‐CD71+ magnetic cell sorting, followed by indirect immunocytochemistry for the detection of γ‐chain fetal hemoglobin. The number of FHE‐NRBC in 10u2009ml maternal blood in the IUGR group was higher than in the control group (454.5 vs 56.7, p<0.05). This difference was even more pronounced when FHE‐NRBC frequency was calculated relative to the total CD71+ population of cells. There were 118.9 FHE‐NRBC per 105 CD71+ cells in IUGR pregnancies as compared with 11.5 cells in the control group (p<0.01). There was no difference in the total mean number of CD71+ mononuclear cells between the two groups. The observed increase in the frequency of fetal cells in the maternal circulation found in IUGR pregnancies may be a result of an increase in total NRBC in the fetal circulation or rather of abnormalities in placental structure. This phenomenon may assist in identifying pregnancies at risk for this complication early in the course of the pregnancy, even before actual growth restriction presents itself ultrasonically. Copyright


American Journal of Obstetrics and Gynecology | 2008

Maternal hypercalcemia as a possible cause of unexplained fetal polyhydramnion: a case series

Hagit Shani; Eyal Sivan; Eran Cassif; Michal J. Simchen

OBJECTIVEnThis study was undertaken to present a possible association between maternal hypercalcemia and fetal polyhydramnion.nnnSTUDY DESIGNnFive cases of maternal hypercalcemia were diagnosed with otherwise unexplained fetal polyhydramnion. Cases are outlined; maternal and fetal/neonatal investigation, treatment, and outcome are presented.nnnRESULTSnFetal polyhydramnion was identified sonographically (mean amniotic fluid index = 32 +/- 11.3 cm). Maternal hypercalcemia (mean 12.8 +/- 1.1 mg/dL) led to the diagnosis of primary hyperparathyroidism. Of the 5 women, 4 underwent parathyroidectomy. One had a hypercalcemic crisis and intrauterine fetal demise. Neonatal hypercalcemia of remaining infants was documented (mean 13 +/- 1 mg/dL), with subsequent hypocalcemia in 1 of the neonates. All mothers and the 4 live neonates were discharged in good condition.nnnCONCLUSIONnWe suggest that fetuses exposed to a hypercalcemic environment may have polyuria develop similar to adult hypercalcemic polyuria, leading to fetal polyhydramnion. Maternal serum calcium levels may be part of the investigation in otherwise unexplained polyhydramnion, as maternal hypercalcemia may threaten the health of both mother and fetus.


Gynecological Endocrinology | 2008

Macrosomia in well controlled CSII treated Type I diabetic pregnancy

Ohad Cohen; Naomi Keidar; Michal J. Simchen; Boaz Weisz; Mordechai Dolitsky; Eyal Sivan

Objective. To survey the effect of tight glycemic control by insulin pumps, of pre-gestational Type 1 diabetic women on pregnancy outcome. Methods. Twelve consecutive Type 1, insulin pump treated, diabetic patients followed in the high risk maternal – fetal clinic were ascertained. Data regarding glucose control was assessed and correlated with pregnancy outcome. Results. A total of 14 deliveries (10 singleton) were assessed. There were no miscarriages, one baby that was born with a ventricular septal defect (VSD). Glycemic control was within the acceptable guidelines. HbA1c (%) by trimesters: 6.5 ± 0.9, 5.9 ± 0.7, 5.8 ± 0.6 and average glucose (mg/dL) 121.0 ± 15.2, 114.8 ± 13.2, 116.0 ± 21.1. Average birth weight was 3312.1 ± 750.2 g with five babies (35%) weighting over 4.0 kg at birth. Birth weight was significantly correlated with HbA1c at the first trimester, mean glucose at trimester 1 and 2, and maternal weight at delivery (r = 0.74, p = 0.045; r = 0.72, p = 0.051; r = 0.74, p = 0.046; r = 0.74, p = 0.04, respectively). Conclusions. Our study of a limited number of patients suggest that women with pre-gestational diabetes obtaining acceptable glycemic goals with insulin pump therapy have increased risk of macrosomia. Current glycemic goals and therapies in treating pre-gestational diabetic patients therefore might not be sufficient to normalise pregnancy outcomes in of women with pre-gestational diabetes.

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