Shali Mazaki-Tovi

Fetal thymus size as a predictor of chorioamnionitis in women with preterm premature rupture of membranes.

Emerging evidence indicates that chorioamnionitis is associated with a significant decrease in thymic size at birth in very low birth weight (VLBW) preterm infants. The aim of this study was to determine whether decreased fetal thymus size is associated with histological or clinical chorioamnionitis in patients with preterm premature rupture of membranes (PROM).

Adiponectin and Leptin Concentrations in Dichorionic Twins with Discordant and Concordant Growth

CONTEXT Discordant twin gestation, in which one fetus is growth restricted, is a unique model that can elucidate the mechanism(s) by which the intrauterine environment affects fetal growth. OBJECTIVE The objective of the study was to determine the cord blood adiponectin and leptin concentrations and evaluate their association with birth weight in dichorionic twins, with and without growth discordance. DESIGN, SETTING, PARTICIPANTS, AND MAIN OUTCOME MEASURE: In this cross-sectional study, arterial cord blood adiponectin and leptin concentrations were determined in two groups of newborns: 1) discordant twins, in which one of the twins is growth restricted (small for gestation age and abnormal umbilical arteries Doppler) and the other is appropriate for gestation age (AGA) (n = 14 pairs); and 2) concordant twins, in which both twins are AGA (n = 15 pairs). RESULTS Results were: 1) within the discordant twins group, the median adiponectin concentration was significantly lower in the growth-restricted newborns than in their cotwins (P = 0.004); 2) within the concordant twin group, there was no significant difference in the median cord blood adiponectin concentration between the two AGA twins; 3) the median leptin concentration did not differ between the twins pairs in both study groups; 4) a positive correlation between cord blood adiponectin concentrations and both birth weight (r = 0.7, P < 0.001) and gestational age (r = 0.6, P < 0.02) was found only in the small-for-gestational-age newborns; 5) linear regression model revealed that birth weight is independently associated with circulating adiponectin concentration. CONCLUSIONS Low circulating adiponectin concentrations, previously reported in adults, children, and infants who were born small for gestational age, characterize fetuses with growth restriction and are independently associated with birth weight.

Should patients with documented fetal lung immaturity after 34 weeks of gestation be treated with steroids

OBJECTIVE The purpose of this study was to determine whether corticosteroid administration after 34 weeks of gestation is associated with improved neonatal outcome in the presence of fetal lung immaturity. STUDY DESIGN We conducted a retrospective cohort study of women who underwent amniocentesis to determine fetal lung maturity from 34-37 weeks of gestation. Patients with negative results (167 women) received steroids based on physician preference and were categorized into 2 groups: study group treated with betamethasone (n = 83 women) and control group in which patients did not receive betamethasone therapy (n = 84 women). The 2 groups were compared with respect to neonatal outcomes. Composite neonatal morbidity was defined as the presence of respiratory distress syndrome, transient tachypnea of the newborn infant, or the need for respiratory support. RESULTS The rate of composite neonatal morbidity was significantly lower among infants who were exposed to steroids compared with the control group (8.4% vs 21%; P = .02). Multiple regression analysis revealed that corticosteroid administration was associated independently with the composite morbidity outcome. CONCLUSION Antenatal steroid administration after 34 weeks of gestation is associated with improved neonatal outcome and should be considered when fetal lung immaturity is documented.

Cell Free Expression of hif1α and p21 in Maternal Peripheral Blood as a Marker for Preeclampsia and Fetal Growth Restriction

Preeclampsia, a severe unpredictable complication of pregnancy, occurs in 6% of pregnancies, usually in the second or third trimester. The specific etiology of preeclampsia remains unclear, although the pathophysiological hallmark of this condition appears to be an inadequate blood supply to the placenta. As a result of the impaired placental blood flow, intrauterine growth restriction (IUGR) and consequential fetal oxidative stress may occur. Consistent with this view, pregnancies complicated by preeclampsia and IUGR are characterized by up-regulation of key transcriptional regulators of the hypoxic response including, hif1α and as well as p53 and its target genes. Recently, the presence of circulating cell-free fetal RNA has been documented in maternal plasma. We speculated that pregnancies complicated by preeclampsia and IUGR, will be associated with an abnormal expression of p53 and/or hif1α related genes in the maternal plasma. Maternal plasma from 113 singleton pregnancies (72 normal and 41 complicated pregnancies) and 19 twins (9 normal and 10 complicated pregnancies) were collected and cell free RNA was extracted. The expression of 18 genes was measured by one step real-time RT-PCR and was analyzed for prevalence of positive/negative expression levels. Results indicate that, among the genes examined, cell free plasma expressions of p21 and hif1α were more prevalent in pregnancies complicated by hypoxia and/or IUGR (p<0.001). To conclude, we present in this manuscript data to support the association between two possible surrogate markers of hypoxia and common complications of pregnancy. More work is needed in order to implement these findings in clinical practice.

Chemerin is present in human cord blood and is positively correlated with birthweight

OBJECTIVE Chemerin, a novel adipokine, has been implicated in adipogenesis, inflammation, and metabolism. The aims of this study were to determine the presence of chemerin in cord blood and its association with birthweight. STUDY DESIGN This cross-sectional study included the following: (1) twins with (n = 24) or without (n = 28) birthweight discordancy; and (2) singletons subclassified into small-for-gestational-age (SGA; n = 18); appropriate for gestational age (AGA; n = 33); and large-for-gestational-age (LGA; n = 8). Cord blood chemerin was determined. Parametric and nonparametric statistics were used for analysis. RESULTS The results of the study included the following: (1) within the discordant twins group, the median chemerin concentration was significantly lower in the SGA group than in their cotwins; (2) within singletons, the median chemerin concentration was significantly higher in the LGA than the AGA newborns; and (3) the regression model revealed that chemerin was independently associated with birthweight. CONCLUSION Cord blood chemerin is present in cord blood and its concentrations are positively correlated with birthweight. These novel findings support a role of adipokines in fetal growth.

Low molecular weight heparin therapy during pregnancy is associated with elevated circulatory levels of placental growth factor

INTRODUCTION Low molecular weight heparin (LMWH) has been shown to be effective in decreasing the recurrence of placenta-mediated complications of pregnant women. The aim of this study was to determine the effect of LMWH on circulating levels of soluble fms-like tyrosine kinase-1 (sFlt-1), soluble endoglin (sEng) and placental growth factor (PLGF) in pregnant women who required anticoagulation therapy. METHODS A longitudinal prospective cohort study was performed including pregnant women in whom anticoagulation therapy by LMWH during pregnancy was clinically indicated (n = 33). Healthy pregnant women, matched for gestational age, who did not require thromboprophylaxis served as controls (n = 29). Maternal plasma samples were obtained throughout gestation every 4 weeks and stored at -70 °C. Maternal plasma concentrations of sFlt-1, sEng and PLGF were determined by ELISA and compared between the two groups. RESULTS Patients treated with LMWH had significantly increased circulatory levels of PLGF during the third trimester compared with controls (28-34 weeks: 719.2 pg/ml vs 558.6 pg/ml at, p < 0.01; 35-40 weeks: 975.6 pg/ml vs 511.2 pg/ml, p < 0.01, respectively). In contrast, circulatory levels of sFlt-1 and sEng were similar between the LMWH treatment group and controls throughout gestation. Consistent with these findings, the ratio of sFlt-1/PLGF was lower in patients treated with LMWH compared to controls (28-34 weeks: 1.9 vs 7.2, p < 0.05; 35-40 weeks: 5 vs 12.9, p < 0.05, respectively). DISCUSSION Anticoagulation treatment of pregnant women with LMWH is associated with a pro-angiogenic state. These findings may explain the effectiveness of LMWH in the prevention of placenta-mediated complications of pregnancy.

Circulating angiogenic factors in monochorionic twin pregnancies complicated by twin-to-twin transfusion syndrome and selective intrauterine growth restriction

OBJECTIVE To determine maternal plasma levels of soluble vascular endothelial growth factor receptor-1 (sVEGFR-1), placental growth factor (PLGF), and soluble endoglin (sEng) in monochorionic diamniotic (MC/DA) twin pregnancies complicated by twin-to-twin transfusion syndrome (TTTS) or selective intrauterine growth restriction (sIUGR). STUDY DESIGN A longitudinal cohort study of pregnant women with MC/DA twins who were classified into 3 groups: (1) uncomplicated MC/DA twins (n = 22), (2) TTTS (n = 23), and (3) sIUGR (n = 15). Maternal plasma samples were obtained between 13-20 and 21-28 weeks of gestation and cord blood samples were collected at delivery. Maternal plasma concentrations of sVEGFR-1, PLGF, and sEng, as well as cord blood levels of sVEGFR-1 were measured by enzyme-linked immunoassay. RESULTS Maternal plasma levels of sVEGFR-1 and sEng were significantly higher in patients with TTTS at the early and late second trimester compared with normal monochorionic pregnancies (P < .01). In contrast, in the sIUGR group, sVEGFR-1 and sEng levels were significantly higher only at the late second trimester (P < .05). PLGF levels were significantly lower at the early and late second trimester in both TTTS and sIUGR compared with controls (P < .01). Plasma concentrations of sVEGFR-1 were significantly higher among TTTS pregnancies compared with sIUGR at the late second trimester (P = .027). Cord blood levels of sVEGFR-1 were significantly higher in the smaller intrauterine growth restricted twin compared with the normal cotwin. CONCLUSION Monochorionic pregnancies complicated by TTTS and sIUGR are characterized by decreased angiogenic activity. The disparity in severity of the antiangiogenic state between TTTS and sIUGR suggests that these 2 conditions may represent a continuum.

Insulin sensitivity in late gestation and early postpartum period: the role of circulating maternal adipokines

Objective. Early postpartum period is characterised by a dramatic decrease in insulin resistance and significant metabolic alterations. The aims of this study were to determine the changes in circulating maternal concentrations of total adiponectin, adiponectin multimers, leptin and resistin before and after the delivery and to explore their relationship with insulin sensitivity. Methods. Twenty-seven normal pregnant women at term were included in this longitudinal study. Blood samples were taken before and 4 days after elective caesarean section. Total adiponectin, adiponectin multimers, leptin, resistin, glucose, insulin and prolactin were measured in maternal serum. Adiponectin multimers were measured before and after the delivery in eight women. Results. (1) The mean maternal serum total adiponectin concentration was significantly higher before than after delivery while the relative distribution of circulating maternal adiponectin multimers did not change after delivery; (2) the median maternal serum concentration of leptin was significantly higher in the antepartum than in the postpartum period; (3) the median maternal serum resistin concentration was comparable before and after delivery; (4) multiple linear regression analysis revealed that antepartum insulin sensitivity was associated with maternal low body mass index, and low glucose concentrations in glucose challenge test, as well as with maternal age and increased leptin concentrations. Postpartum insulin sensitivity was associated with decreased circulating resistin concentrations. Conclusions. Despite increase in insulin sensitivity, early postpartum period is characterised by a decrease in maternal circulating total adiponectin and by steady concentrations of resistin and adiponectin multimers compared to the late third trimester.

Mode of delivery of twin gestation with very low birthweight: is vaginal delivery safe?

OBJECTIVE The purpose of this study was to determine whether planned vaginal delivery is associated with increased risk of perinatal death and morbidity in twin pregnancies that are complicated by a very low birthweight of the second twin. STUDY DESIGN We conducted a retrospective cohort study of twin pregnancies in which the second twins birthweight was ≤1500 g. One hundred ninety-three twin gestations met the study criteria; patients were classified into 2 groups according to the planned mode of delivery: (1) cesarean delivery (n = 142) and (2) vaginal delivery (n = 51). In the vaginal delivery group, 21 pairs were in cephalic-cephalic presentation at the time of delivery; 28 pairs were cephalic-noncephalic, and 2 pairs were noncephalic-noncephalic. Composite adverse neonatal outcome was defined as the presence of neonatal death, respiratory distress syndrome, sepsis, necrotizing enterocolitis, or intraventricular hemorrhage grade 3-4. RESULTS Trial of vaginal delivery was successful for both twins in 90.5% of cephalic-cephalic twins and 96.4% in cephalic-noncephalic twins. The rate of intraventricular hemorrhage was significantly higher in the vaginal delivery group (29.4% vs 8.5%, respectively; P = .013; adjusted odds ratio [OR], 3.65; 95% confidence interval [CI], 1.32-10.1). The increased risk of intraventricular hemorrhage in the vaginal delivery groups was evident in both twin A (17.6% vs 7.0%; P = .029) and twin B (15.7% vs 4.9%; P = .014); however, these differences were not significant after adjustment for possible confounders (twin A: adjusted OR, 1.79; 95% CI, 0.58-5.55; twin B: adjusted OR, 2.13; 95% CI, 0.63-7.25). In addition, subgroup analysis revealed that both cephalic-cephalic and cephalic-noncephalic twins who were delivered vaginally had increased risk for intraventricular hemorrhage. There were no significant differences between the cesarean and vaginal delivery groups in the rates of Apgar score <7 at 5 minutes, arterial cord pH <7.1, composite adverse neonatal outcome, and neonatal mortality rate. However, the rate of respiratory distress syndrome was significantly lower in the vaginal delivery group (66.7% vs 69%; P = .042; OR, 0.34; 95% CI, 0.12-0.96). CONCLUSION Vaginal delivery of very low birthweight twins is associated with an increased risk of intraventricular hemorrhage, regardless of presentation. Because of the small sample size and the retrospective cohort design, large prospective randomized studies are needed.

Can middle cerebral artery peak systolic velocity predict polycythemia in monochorionic–diamniotic twins? Evidence from a prospective cohort study

The antenatal diagnosis of twin anemia–polycythemia sequence (TAPS) in monochorionic–diamniotic (MCDA) twin pregnancies is based on elevated peak systolic velocity in the middle cerebral artery (MCA‐PSV) in the donor twin and decreased MCA‐PSV in the recipient twin. However, the association between these parameters and polycythemia has not yet been established. The aim of this study was to determine whether MCA‐PSV can predict polycythemia in MCDA pregnancies.