Volume 38, Issue 5

Objective: The management of monochorionic (MC) twin pregnancies varies in different medical centers. This paper compares screening methods to predict the complications of the MC twin pregnancy and different treatment methods. Methods: We performed a literature search without language restriction in Cochrane library and PubMed (1970–2009). Case series and cohort screening studies, pathogenesis and management of complications of MC pregnancy were included. Results: Elevated risk for intrauterine fetal death (IUFD) and twin-to-twin transfusion syndrome (TTTS) can be detected sonographically. Monitoring of MC pregnancies at increased risk and regular training sessions for the operating team combined with reduced fetoscopic amniotic membrane damage increase fetal survival rate from laser coagulation to nearly 100% for at least one fetus and to 90% for both. Conclusion: Monitoring of MC pregnancies at increased risk and laser treatment of TTTS in medical centers with sufficient experience might improve neonatal outcome.

Objective: To assess longitudinally the changes in cervical volume and vascularization during the peripartum period using three-dimensional ultrasound (3D US) and power Doppler and to determine whether these measures change with gestational complications. Methods: Longitudinal measurements of cervical dimensions by transvaginal 3D US and power Doppler using the virtual organ computer-aided analysis program were performed at 11–14, 22–24, 32–34 weeks' gestation, and at 6 weeks' postpartum in 111 pregnant women. Comparisons were made between women who delivered at term (vs. preterm), nulliparous (vs. parous), with (vs. without) pre-eclampsia and those with (vs. without) gestational diabetes. Results: After establishing reference values for each peripartum period for cervical volume, vascularization index (VI) and flow index (FI), we found that the 2 nd and 3 rd trimester volume, 2 nd trimester FI and postpartum VI were different in nulli- vs. multiparous women. Volume and vascularization parameters were unaffected by preterm labor. Second trimester VI and vascularization flow index values were lower in pre-eclamptic vs. non-pre-eclamptic women (P<0.05), but unaffected by gestational diabetes. Conclusion: Cervical volume and vascularization parameters are not helpful in predicting preterm labor and gestational diabetes, but might be associated with pre-eclampsia.

Aims: The aim of this study was to investigate the significance of Doppler ultrasound as a predictor for adverse pregnancy outcomes in Korean women with anemia during the third trimester of pregnancy. Methods: A retrospective study comparing women with (n=377) and without (n=3183) anemia was performed. Maternal anemia was defined as hemoglobin concentration <10 g/dL. Umbilical artery Doppler (UmA) and uterine artery Doppler (UtA) velocimetry was performed before delivery. Results: There were higher rates of small for gestational age, cesareans for fetal distress, and preterm birth among the anemic compared to non-anemic women. When maternal anemia was combined with abnormal Doppler, the odds ratio (OR) of adverse pregnancy outcome was further increased. Both abnormal UtA and UmA to predict adverse pregnancy outcome showed sensitivity, specificity, positive and negative predictive values of 41.2%, 97.4%, 85.9%, and 51.2%, respectively (OR 2.0; 95% confidence interval 1.2–2.3). Conclusions: Doppler ultrasound examination could be used as a predictor for adverse pregnancy outcomes in women with anemia during the third trimester.

Objective: We assessed the impact of selenium, a trace element with antioxidant properties on a simple measure of oxidative stress in pregnant women. Study design: A novel assay of prooxidant-antioxidant balance (PAB) was applied in a double-blind, placebo-controlled study of selenium supplementation in pregnancy. We measured the prooxidant burden and the antioxidant capacity simultaneously in one assay, thereby calculating a redox index. A total of 166 primigravid pregnant women in the first trimester of pregnancy, were randomized to receive 100 μg of selenium (n=83) or placebo (n=83) per day until delivery. PAB values and serum selenium concentrations were measured at baseline and at the end of study. Results: Pretreatment demographic data and biochemical indices including serum selenium concentrations did not differ significantly between the groups. The drop-out rates for the groups were 22/83 and 19/83 for the selenium and placebo groups, respectively. Supplementation with selenium was associated with a significant increase in mean serum selenium concentration (P<0.001) but without significant change in mean PAB value. In contrast, mean serum selenium concentration remained unchanged and mean PAB values increased significantly (P<0.05 in the control group). Conclusion: Our findings suggest that selenium supplementation may reduce oxidative stress associated with pregnancy.

Aim: To compare cervical length (CL) at 18–21 and 22–25 weeks' gestation in twin pregnancies in prediction of spontaneous preterm delivery and to examine cervical shortening. Methods: Retrospective cohort study of CL measured at 18–21 and 22–25 weeks' gestation in twin pregnancies. Results: Receiver operating characteristics (ROC) curve revealed area of 0.64 (95% CI 0.53–0.75) and 0.80 (95% CI 0.72–0.88) for measurements at 18–21 and 22–25 weeks, respectively (P≤0.001). Sensitivities of 33.3% and 23% and negative predicting value (NPV) of 97.3% and 86.8% for delivery at <28 and <34 weeks gestation were reached for measurements at 18–21 weeks. Sensitivities of 71.4% and 38.2% and NPV of 99.1% and 91.4% for delivery at <28 and <34 weeks' gestation were reached for measurements at 22–25 weeks. Cervical length shortening analysis showed an area under ROC curve of 0.81 (95% CI 0.73–0.89) and best cut-off was at ≥2 mm/week. Sensitivities of 80% and 60.8% and NPV of 98.9% and 90.6% for delivery at <28 and <34 weeks gestation were reached. Conclusions: In twin gestations, assessment of CL at 22–25 weeks is better than assessment at 18–21 weeks to predict preterm delivery before 34 weeks. Cervical shortening at a rate of ≥2 mm/weeks between 18 and 25 weeks gestation was a good predictor of spontaneous preterm birth in this high-risk population.

Objective: To evaluate differences in placental lesions in twin pregnancies with and without mid-trimester sonographic cervical shortening. Methods: Two groups of women were identified: those with twin gestations and a cervical length ≤2.5 cm measured between 16 and 24 weeks of gestation and those with twin gestations and without evidence of cervical shortening. The placental pathology was then retrospectively reviewed. The placental lesions were categorized as either acute or chronic inflammatory lesions, lesions of malperfusion or coagulopathic lesions. Results: A total of 704 patients with twin gestations were identified. There was significantly more acute chorioamnionitis in patients with cervical shortening but no differences in the frequency of other placental lesions. Conclusion: Placentas with acute inflammatory lesions are significantly more frequent in twin gestations with mid-trimester cervical shortening.

Aims: To evaluate uterine cervical consistency using a vaginal ultrasound gray-level histogram. Methods: Vaginal ultrasound and digital examination were performed for 214 women with low-risk singleton pregnancy during 27–30 th pregnancy week. The mean gray-level (MGL) of an ultrasound gray-level histogram, representing the echogenicity of a region of interest, was measured in the midsection of anterior and posterior cervical walls. The difference in MGL between anterior and posterior (AP difference) was related to the Bishop sub-score for cervical consistency (0, 1, or 2), determined before ultrasound. Results: A larger positive AP difference indicated significantly lower Bishop sub-score. After analyzing the receiver operator characteristic curves for the AP difference, a value of 1.42 and –1.98 was the best cut-off value to determine a hard cervix (score 0) and a soft cervix (score 2), respectively. To identify a hard cervix, this test had 71% sensitivity and 82% specificity. For a soft cervix, it was 66% and 87%, respectively. Conclusions: A more echogenic anterior than posterior cervix indicates a hard cervix; the greater the difference in echogenicity between anterior and posterior walls the harder the cervix. The difference in MGL of the ultrasound gray-level histogram may enable objective evaluation of cervical consistency.

Objective: Microbial invasion of the amniotic cavity (MIAC) has been detected in women with preterm labor, preterm prelabor rupture of membranes (PROM), and in patients at term with PROM or in spontaneous labor. Intrauterine infection is recognized as a potential cause of fetal growth restriction; yet, the frequency of MIAC in pregnancies with small-for-gestational-age (SGA) fetuses is unknown. The aim of this study was to determine the frequency, diversity and relative abundance of microbes in amniotic fluid (AF) of women with an SGA neonate using a combination of culture and molecular methods. Method: AF from 52 subjects with an SGA neonate was analyzed with both cultivation and molecular methods in a retrospective cohort study. Broad-range and group-specific PCR assays targeted small subunit rDNA, or other gene sequences, from bacteria, fungi and archaea. Results of microbiologic studies were correlated with indices of the host inflammatory response. Results: 1) All AF samples (n=52) were negative for microorganisms based on cultivation techniques, whereas 6% (3/52) were positive based on PCR; and 2) intra-amniotic inflammation was detected in one of the three patients with a positive PCR result, as compared with three patients (6.1%) of the 49 with both a negative culture and a negative PCR (P=0.2). Conclusion: MIAC is detected by PCR in some patients with an SGA fetus who were not in labor at the time of AF collection.

Objective: Infection has been implicated in the pathogenesis of preeclampsia, yet the association between microbial invasion of the amniotic cavity (MIAC) and preeclampsia has not been determined. The aim of this study was to determine the prevalence, and microbial diversity associated with MIAC, as well as the nature of the host response to MIAC in patients with preeclampsia. Method of study: Amniotic fluid (AF) from 62 subjects with preeclampsia, not in labor, was analyzed with both cultivation and molecular methods. Broad-range and group-specific PCR assays targeting small subunit ribosomal DNA, or other gene sequences, from bacteria, fungi and archaea were used. Results were correlated with measurements of host inflammatory response, including AF white blood cell count and AF concentrations of glucose, interleukin-6 (IL-6) and MMP-8. Results: 1) The rate of MIAC in preeclampsia was 1.6% (1/62) based on cultivation techniques, 8% (5/62) based on PCR, and 9.6% (6/62) based on the combined results of both methods; 2) among the six patients diagnosed with MIAC, three had a positive PCR for Sneathia/Leptotrichia spp.; and 3) patients with MIAC were more likely to have evidence of an inflammatory response in the amniotic cavity than those without MIAC, as determined by a higher median AF IL-6 [1.65 ng/mL interquartile range (IQR): 0.35–4.62 vs. 0.22 ng/mL IQR: 0.12–0.51; P=0.002). Conclusion: The prevalence of MIAC in preeclampsia is low, suggesting that intra-amniotic infection plays only a limited role in preeclampsia. However, the unexpectedly high number of positive AF specimens for Sneathia/Leptotrichia warrants further investigation.

Background: Pregnant women and infants have significant exposures to the most commonly used plasticizer di-(2-ethylhexyl) phthalate (DEHP). Objectives: This study was designed to evaluate the effects of DEHP exposure on growth and lung maturation in rats and determine if DEHP regulation of 11β-hydroxysteroid dehydrogenase type 1 gene ( Hsd11b1 ) expression in the lung tissue plays a role in its effects on lung maturation. Method: Pregnant Sprague-Dawley rats were treated from gestational day 12 to postnatal day (PND) 21 with DEHP orally at dosages of 0, 10, 100 or 750 mg/kg/day, respectively (n=8 for each group). Two rat pups (one male and one female) from each litter were sacrificed at PND 1 and 21. Body weight was measured and the lung was processed for histology and calculation of lung interstitial tissue proportion as well as real-time PCR determination of the expressions of Hsd11b1 , surfactant associated protein-A1 gene ( Sftpa1 ) and B gene ( Sftpb ). Results: The perinatal DEHP exposure led to a dose dependent intrauterine and postnatal growth restriction (P<0.001). High dose DEHP (750 mg/kg/day) exposure led to decreased gas-exchange space as evidenced by increased lung interstitial tissue proportion (P<0.001), but did not cause significant changes in Hsd11b1 , Sftpa1 or Sftpb gene expression in the rat lung at PND 1. The DEHP-induced change in lung histology remained significant at PND 21 with improvement despite continual exposure to DEHP. Conclusion: Perinatal DEHP exposure leads to growth restriction and delayed lung maturation in newborn rats.

Objective: To determine cord blood levels of calprotectin, a protein that is increased in inflammatory states and released by activated neutrophils has apoptosis-inducing activity. Materials and methods: Cord-blood calprotectin concen-trations were determined in intrauterine-growth-restricted (IUGR, usually associated with increased neutrophil activation and apoptosis, n=50) and appropriate-for-gestational-age (AGA, n=110) single full-term pregnancies, and were correlated with perinatal demographic parameters. Results: No significant differences exists between the IUGR and AGA groups, implying that calprotectin at birth does not reflect increased neutrophil activation and apoptosis expected in IUGR. However, in IUGRs, calprotectin concentrations increased with every gestational week [b=45.3, 95% confidence interval (CI): 13.5–77.1, P=0.006], suggesting concomitant up-regulation of neutrophil activation and apoptosis. A combined group showed significantly decreased calprotectin concentrations in cesarean sections [b=–74.5, 95% CI: –115.2–(–33.9), P<0.001], pointing to excessive inflammatory response in vaginal deliveries. Finally, birth weight, customized centile, gender, maternal age and parity do not impact on cord blood calprotectin concentrations. Conclusions: Cord blood calprotectin concentrations at term are independent of intrauterine growth, gender, parity and maternal age and probably do not reflect the increased neutrophil activation and excessive apoptosis expected in IUGR.

Aims: To evaluate the C-reactive protein (CRP) and interleukin-6 (IL-6) as diagnostic tools for early onset infection in preterm infants with early respiratory distress (RD). Methods: CRP and IL-6 were quantified at identification of RD and 24 h after in 186 newborns. Effects of maternal hypertension, mode of delivery, Apgar score, birth weight, gestational age, mechanical ventilation, being small for gestational age (SGA), and the presence of infection were analyzed. Results: Forty-four infants were classified as infected, 42 as possibly infected, and 100 as uninfected. Serum levels of IL-6 (0 h), CRP (0 h), and CRP (24 h), but not IL-6 (24 h) were significantly higher in infected infants compared to the remaining groups. The best test for identification of infection was the combination of IL-6 (0 h) 36 pg/dL and/or CRP (24 h) 0.6 mg/dL, which yielded 93% sensitivity and 37% specificity. The presence of infection and vaginal delivery independently increased IL-6 (0 h), CRP (0 h) and CRP (24 h) levels. Being SGA also increased the CRP (24 h) levels. IL-6 (24 h) was independently increased by mechanical ventilation. Conclusions: The combination of IL-6 (0 h) and/or CRP (24 h) is helpful for excluding early onset infection in preterm infants with RD but the poor specificity limits its potential benefit as a diagnostic tool.

Objective: Forces transmitted to the neonate as a consequence of accelerations during transport have been associated with adverse neonatal outcomes including broncho-pulmonary dysplasia. In this study, we sought to determine the relationship between the duration of transport and respiratory performance in the rat model. Methods: Four groups of Sprague-Dawley rat pups (10–12 pups/groups) were exposed to simulated medical transport on postnatal day of life 11 or 12. Each group was exposed to an average impulse of 27.4 m/s 2 /min for 0, 30, 60 or 90 min. During the exposure periods, impulse was monitored by computerized sampling using a digital accelerometer. Post-exposure, animals were immediately prepared, placed on mechanical ventilation and analyzed for elastance, tissue damping, airway resistance, ratio of damping to elastance (eta), hysteresivity, and inertance at positive end expiratory pressures (PEEPs) of 0, 3 and 6 cm 3 of H 2 O. Total phospholipid content and surfactant proteins A, B, and C mRNA levels in broncho-alveolar lavage fluid and lung tissue were obtained. Results: Increased transport time resulted in a significant step-wise increase in airway resistance at all levels of PEEP (P<0.01). Static compliance decreased significantly after 60 min at PEEPs of 3 and 6 cm H 2 O (P<0.01). Eta significantly decreased with greater transport time at a PEEP of 6 cm H 2 O (P<0.05). Tissue damping increased with duration of transport time across all PEEP levels, but only exhibited statistical significance at a PEEP of 0 cm H 2 O (P<0.05). No differences were seen in hysteresivity or inertance. Compared with controls, transport was associated with significant reductions in total phospholipid content and mRNA levels of surfactant proteins B and C. Conclusion: Rat pups experienced significant deterioration of respiratory function with increasing duration of simulated transport.

Mild hypothermia can attenuate the development of brain damage after asphyxia. Supplemental oxygen during resuscitation increases generation of reactive oxygen species, compared to room air. It is unknown if supplemental oxygen affects hypothermic neuroprotection. We studied the early effects of hyperoxic reoxygenation and subsequent hypothermia on tissue oxygenation, microcirculation, inflammation and brain damage after global hypoxia. Anesthetized newborn pigs were randomized to control (n=6), or severe global hypoxia (n=46). Three pigs died during hypoxia or reoxygenation. After 20-min reoxygenation with room air (n=22) or 100% oxygen (n=21), pigs were randomized to normothermia (deep rectal temperature 39°C, n=22) or total body cooling (35°C, n=21) for 6.5 h before the experiment was terminated. We demonstrated a differential effect of post-hypoxic hypothermia between animals reoxygenated with 100% oxygen and with room air, with reduced damage only in hypothermic animals reoxygenated with 100% oxygen (P=0.001). Hyperoxic reoxygenation resulted in a significant overshoot in striatal oxygen tension, without affecting microcirculation. Inflammatory response after the insult did not differ between groups. The results indicate an early protective effect of hypothermia which may vary with oxygen level used during reoxygenation.

Objective: Recent ultrasonographic studies suggest that the administration of surfactant to preterm infants with respiratory distress syndrome (RDS) does not affect lung water clearance. The purpose of the study was also to look at clearance of lung water in preterm rabbits receiving surfactant. Methods: Lung ultrasound was performed in 73 neonates at different gestational ages (range 23–34 weeks) with radiological and clinical signs of RDS, before and after surfactant administration. In premature rabbits (28–29 days’ gestational age), either receiving or not receiving surfactant, we followed the time course of lung water balance considering the wet weight/dry weight ratio, the morphology and compliance of alveoli and pulmonary interstitial pressure. Results: In all RDS infants lung ultrasound images consistently showed a generalized increase in extravascular lung fluid which remained unchanged after surfactant administration and did not affect the rate of fluid clearance. Surfactant administration in premature rabbits did not improve the time course of lung fluid clearance. Conclusions: Data from ultrasound in preterm babies are confirmed by animal experiments.

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No Abstract available