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Subject: This study investigates the placental autophagic activity in growth-restricted fetuses in the monochorionic (MC) twin model., Patients and Methods: Forty MC twins were prospectively enrolled in this study, including 21 with and 19 without selective intrauterine growth restriction (sIUGR), defined as birth weight below the tenth percentile. The sIUGR group was subdivided on the basis of present versus absent or reversed umbilical artery end-diastolic flow at Doppler. Placenta samples were taken after delivery from each twin placenta territories. After protein extraction, Western blot was used to determine light chain 3 (LC3)-II placental protein expression in sIUGR and appropriately grown (appropriate-for-gestational age, AGA) twins., Results: The LC3-II was significantly higher in the sIUGR twin placental territory than in their AGA counterparts. In the sIUGR group, LC3-II fold change was significantly increased compared with that in the AGA cotwins (2.28 vs 1.04, p < 0.05). Placental LC3-II protein expression was particularly stimulated in the MC sIUGR group with abnormal umbilical artery Doppler flow compared with AGA controls (p < 0.05, one-way analysis of variance test)., Conclusions: In MC twins, the placental autophagic activity is different between sIUGR and AGA cotwins. The placenta territory with the least blood flow perfusion has the highest autophagic activity., (© 2013 John Wiley & Sons, Ltd.)

This study was designed to evaluate the degree of placenta share discordance in relation to the betamethasone-induced return of positive end-diastolic flow in monochorionic twin pregnancies with selective intrauterine growth restriction (sIUGR) and abnormal umbilical artery Doppler. Monochorionic twins with sIUGR was defined as one twin having an estimated fetal weight below the 10th percentile combined with an estimated fetal weight discordance >25%. The umbilical artery Doppler directly prior to (D0) and 24 hours (D1) and 48 hours (D2) after the first dose of betamethasone administration was recorded. The estimated individual placental weight in monochorionic twins was obtained by cutting the placenta along the vascular equator into two territories; the placenta share discordance was calculated as [(estimated individual placental weight of appropriated for gestational age twin- estimated individual placental weight of growth restricted twin)/estimated individual placental weight of appropriated for gestational age twin] × 100%. Six (23.1%) of the 26 included cases achieved betamethasone-induced return of positive umbilical artery end-diastolic flow. The difference of placenta share discordance and birth weight discordance were not significantly different between twins with and without betamethasone-induced return of positive umbilical artery end-diastolic flow. Thus, according to our study results, it was proposed that although the placenta share discordance correlated with the abnormal umbilical artery Doppler in the IUGR fetus in monochorionic twin, the betamethasone-induced return of positive umbilical artery end-diastolic flow, however, did not reveal the similar relationship with the severity of placenta share discordance.

Labor and its associated pain are thought to have unique impacts on parturient women. The goal of this study was to investigate the effects of labor and associated pain on differential gene expression profiles in the maternal, fetal, and placental compartments. We used microarrays to analyze maternal blood (MB), fetal cord blood (CB), and placental tissue samples in pregnant women after term vaginal deliveries (laboring group) and in term pregnant women after scheduled Ceasarean sections (nonlaboring group). The upregulated genes in the MB of the laboring group are involved in cytokine and nuclear factor-kappa B signaling pathways, regulation of the networks of toll-like receptor 4, and suppressor of cytokine signaling 3. Upregulated genes in the CB of the laboring group are involved in responding to stress and stimuli by regulating the network genes of the T-cell receptor beta locus and the FK506 binding protein 8. Differentially expressed genes in the placenta of the laboring group are involved in nitric oxide transport, gas transport, response to hydrostatic pressure, oxygen transport, acute phase responses, and the tumor necrosis factor-mediated signaling pathway, which are important during the transient hypoxemia and hypoperfusion that occur in the placenta during uterine contractions. Interestingly, few of the genes exhibited simultaneous changes in all three compartments, indicating that different pathways and complex interactions may be involved in human labor. In conclusion, human labor and its associated pain elicit unique gene regulatory changes in MB, placenta, and CB., (Copyright © 2011. Published by Elsevier B.V.)

This study was conducted to investigate the relationship among umbilical venous volume flow, birthweight and placental share in monochorionic twins with or without selective growth restriction. Having excluded cases complicated with twin-to-twin transfusion syndrome and one co-twin suffering intrauterine fetal death, a total of 51 monochorionic twin pregnancies were divided into two groups as with (group 1) and without (group 2) selective intrauterine growth restriction. Umbilical venous volume flow was calculated by multiplying the umbilical vein cross-sectional area by half of the maximal velocity around mid-trimester. The placentas were cut along the vascular equator into two individual placental masses. The discordance of birthweight was calculated as [(birthweight of larger twin-birthweight of smaller twin)/birthweight of larger twin 100%]. The discordances of umbilical venous volume flow and placental share were calculated in a similar fashion. The median umbilical venous volume flow discordances (68.4% and 15.3% in groups 1 and 2 monochorionic twins, respectively) were similar and correlated well with the placental share discordances (66.6% and 18.5% in groups 1 and 2 monochorionic twins, respectively) but not with the birthweight discordance (28.6% and 6.4% in groups 1 and 2 monochorionic twins, respectively) in both groups. We concluded that the umbilical venous volume flow discordance reflects the placental share discordance rather than the birthweight discordance in monochorionic twin pregnancies.

Objective: To evaluate the clinical outcome and placental territory ratio in monochorionic diamniotic (MCDA) twin pregnancies and selective intrauterine growth restrictions (sIUGR) with different types of umbilical artery (UA) Doppler., Study Design: An MCDA twin pregnancy with sIUGR was defined as a fetal weight below the 10th percentile in one twin. MCDA twins were divided into three groups: without IUGR (group I); with sIUGR, and a normal UA Doppler (group II); or an abnormal UA Doppler (persistent absence or reverse of end-diastolic velocity) (group III). Placental territory was calculated as the estimated individual placental mass/total placenta weight., Results: Altogether, 27 cases of group I, 11 cases of group II and 13 cases of group III MCDA twins were included. The placenta territory of the IUGR twin in group III MCDA twin was the smallest among the three groups of MCDA twins (ANOVA test, p < 0.001). There was incidence of neonatal death in six (6/26) of group III MCDA fetuses, while none in groups I and II MCDA twins did., Conclusions: In MCDA twins with sIUGR, abnormal UA Doppler in the IUGR twin may reflect a more severe unequal placenta share and poorer neonatal outcomes. The prognosis of group II MCDA twins, even with sIUGR found in early gestation, is, by contrast, better.

Objectives: To evaluate the individual fetal weight/estimated placental weight ratios (F/P ratio) of the two fetuses in monochorionic (MC) twins with selective intrauterine growth restriction (IUGR)., Material and Methods: MC twin with selective IUGR was defined as an estimated fetal weight below the 10th percentile in one twin of MC pregnancy. The estimated individual placental weight was obtained by cutting the placenta along the vascular equator into two territories. A total of 15 MC twins with selective IUGR and 18 MC twins without selective IUGR were included in this study., Results: The individual F/P ratio in the IUGR twin is significantly higher than that in the appropriate for gestational age (AGA) one in MC twin with selective IUGR (6.4 vs 4.0 respectively, p < 0.001). In MC twin without IUGR, the F/P ratios are not significantly different between the two fetuses (5.4 vs 5.1, respectively)., Conclusion: The high F/P ratio in the IUGR twin in MC with selective IUGR may be due to the placental reserve phenomenon, so that a smaller placental territory may suffice to perfuse the IUGR twin. In other words, in MC twin gestations with an IUGR twin, the fetal weights are not proportional to the placental masses., (Copyright (c) 2008 John Wiley & Sons, Ltd.)