Effect of delayed cord clamping on red blood cell alloimmunization: a retrospective cohort study.

BACKGROUND: Although delayed cord clamping has well-known benefits for preterm and term neonates, it has been inadequately assessed in alloimmunized neonates. OBJECTIVE: This study aimed to evaluate the benefits and risks of delayed cord clamping in alloimmunized neonates. STUDY DESIGN: This was a retrospective comparative pre-post cohort study conducted from 2003 to 2018 in a tertiary care center in France. All living singleton neonates whose mothers were followed up for red blood cell alloimmunization during gestation and confirmed at birth (N=224) were included. Neonates were either exposed to immediate (n=125) or delayed cord clamping (n=99). Our main outcome was the time from birth to first exchange transfusions and/or transfusions. Secondary outcomes were hemoglobin level at birth, rate of exchange transfusion, number of postnatal transfusions, maximum bilirubin level, and number of phototherapy hours. RESULTS: Hemoglobin at birth was significantly higher in case of delayed cord clamping (mean difference, 1.7 g/dL; 95% confidence interval, 0.7-2.8). Among infants treated with exchange transfusion or transfusion, the time to initial treatment was higher in case of delayed cord clamping (median difference, 8 days; rate ratio, 1.51; 95% confidence interval, 1.09-2.10). There were no significant differences in the need for exchange transfusion, the number of transfusions, the maximum total bilirubin level, nor the number of phototherapy hours. In the subgroup analysis of neonates needing intrauterine transfusion during pregnancy (ie, severe alloimmunization), neonates had a lower rate of exchange transfusion in case of delayed cord clamping (odds ratio, 0.36; 95% confidence interval, 0.15-0.82). CONCLUSION: Our results indicate a benefit of delayed cord clamping in alloimmunization, regardless of pathology severity, without increased risk of jaundice.

Association Between Early Amino Acid Intake and Full-Scale IQ at Age 5 Years Among Infants Born at Less Than 30 Weeks' Gestation.

Importance: An international expert committee recently revised its recommendations on amino acid intake for very preterm infants, suggesting that more than 3.50 g/kg/d should be administered only to preterm infants in clinical trials. However, the optimal amino acid intake during the first week after birth in these infants is unknown. Objective: To evaluate the association between early amino acid intake and cognitive outcomes at age 5 years. Design, Setting, and Participants: Using the EPIPAGE-2 (Epidemiologic Study on Small-for-Gestational-Age Children-Follow-up at Five and a Half Years) cohort, a nationwide prospective population-based cohort study conducted at 63 neonatal intensive care units in France, a propensity score-matched analysis was performed comparing infants born at less than 30 weeks' gestation who had high amino acid intake (3.51-4.50 g/kg/d) at 7 days after birth with infants who did not. Participants were recruited between April 1 and December 31, 2011, and followed up from September 1, 2016, to December 31, 2017. Full-scale IQ (FSIQ) was assessed at age 5 years. A confirmatory analysis used neonatal intensive care unit preference for high early amino acid intake as an instrumental variable to account for unmeasured confounding. Statistical analysis was performed from January 15 to May 15, 2021. Exposures: Amino acid intake at 7 days after birth. Main Outcomes and Measures: The primary outcome was an FSIQ score greater than -1 SD (ie, ≥93 points) at age 5 years. A complementary analysis was performed to explore the association between amino acid intake at day 7 as a continuous variable and FSIQ score at age 5 years. Data from cerebral magnetic resonance imaging at term were available for a subgroup of preterm infants who participated in the EPIRMEX (Cerebral Abnormalities Detected by MRI, Realized at the Age of Term and the Emergence of Executive Functions) ancillary study. Results: Among 1789 preterm infants (929 boys [51.9%]; mean [SD] gestational age, 27.17 [1.50] weeks) with data available to determine exposure to amino acid intake of 3.51 to 4.50 g/kg/d at 7 days after birth, 938 infants were exposed, and 851 infants were not; 717 infants from each group could be paired. The primary outcome was known in 396 of 646 exposed infants and 379 of 644 nonexposed infants who were alive at age 5 years and was observed more frequently among exposed vs nonexposed infants (243 infants [61.4%] vs 206 infants [54.4%], respectively; odds ratio [OR], 1.33 [95% CI, 1.00-1.71]; absolute risk increase in events [ie, the likelihood of having an FSIQ score >-1 SD at age 5 years] per 100 infants, 7.01 [95% CI, 0.06-13.87]; P = .048). In the matched cohort, correlation was found between amino acid intake per 1.00 g/kg/d at day 7 and FSIQ score at age 5 years (n = 775; ß = 2.43 per 1-point increase in FSIQ; 95% CI, 0.27-4.59; P = .03), white matter area (n = 134; ß = 144 per mm2; 95% CI, 3-285 per mm2; P = .045), anisotropy of the corpus callosum (n = 50; ß = 0.018; 95% CI, 0.016-0.021; P < .001), left superior longitudinal fasciculus (n = 42; ß = 0.018; 95% CI, 0.010-0.025; P < .001), and right superior longitudinal fasciculus (n = 42; ß = 0.014 [95% CI, 0.005-0.024; P = .003) based on magnetic resonance imaging at term. Confirmatory and sensitivity analyses confirmed these results. For example, the adjusted OR for the association between the exposure and the primary outcome was 1.30 (95% CI, 1.16-1.46) using the instrumental variable approach among 978 participants in the overall cohort, and the adjusted OR was 1.35 (95% CI, 1.05-1.75) using multiple imputations among 1290 participants in the matched cohort. Conclusions and Relevance: In this cohort study, high amino acid intake at 7 days after birth was associated with an increased likelihood of an FSIQ score greater than -1 SD at age 5 years. Well-designed randomized studies with long-term follow-up are needed to confirm the benefit of this nutritional approach.

Maternal omega-3 PUFA supplementation prevents hyperoxia-induced pulmonary hypertension in the offspring.

Pulmonary hypertension (PH) and right ventricular hypertrophy (RVH) affect 16-25% of premature infants with bronchopulmonary dysplasia (BPD), contributing significantly to perinatal morbidity and mortality. Omega-3 polyunsaturated fatty acids (PUFA ω-3) can improve vascular remodeling, angiogenesis, and inflammation under pathophysiological conditions. However, the effects of PUFA ω-3 supplementation in BPD-associated PH are unknown. The present study aimed to evaluate the effects of PUFA ω-3 on pulmonary vascular remodeling, angiogenesis, and inflammatory response in a hyperoxia-induced rat model of PH. From embryonic day 15, pregnant Sprague-Dawley rats were supplemented daily with PUFA ω-3, PUFA ω-6, or normal saline (0.2 ml/day). After birth, pups were pooled, assigned as 12 per litter, randomly assigned to either air or continuous oxygen exposure (fraction of inspired oxygen = 85%) for 20 days, and then euthanized for pulmonary hemodynamic and morphometric analysis. We found that PUFA ω-3 supplementation improved survival, decreased right ventricular systolic pressure and RVH caused by hyperoxia, and significantly improved alveolarization, vascular remodeling, and vascular density. PUFA ω-3 supplementation produced a higher level of total ω-3 in lung tissue and breast milk and was found to reverse the reduced levels of VEGFA, VEGF receptor 2, angiopoietin-1 (ANGPT1), endothelial TEK tyrosine kinase, endothelial nitric oxide synthase, and nitric oxide concentrations in lung tissue and the increased ANGPT2 levels in hyperoxia-exposed rats. The beneficial effects of PUFA ω-3 in improving lung injuries were also associated with an inhibition of leukocyte infiltration and reduced expression of the proinflammatory cytokines IL-1ß, IL-6, and TNF-α. These data indicate that maternal PUFA ω-3 supplementation strategies could effectively protect against infant PH induced by hyperoxia.

Effects of Eicosapentaenoic Acid (EPA) and Docosahexaenoic Acid (DHA) on Fetal Pulmonary Circulation: An Experimental Study in Fetal Lambs.

Background: Persistent pulmonary hypertension of the newborn (PPHN) causes significant morbidity and mortality in neonates. n-3 Poly-unsaturated fatty acids have vasodilatory properties in the perinatal lung. We studied the circulatory effects of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in fetal sheep and in fetal pulmonary arterial rings. Methods: At 128 days of gestation, catheters were placed surgically in fetal systemic and pulmonary circulation, and a Doppler probe around the left pulmonary artery (LPA). Pulmonary arterial pressure and LPA flow were measured while infusing EPA or DHA for 120 min to the fetus, to compute pulmonary vascular resistance (PVR). The dose effects of EPA or DHA were studied in vascular rings pre-constricted with serotonin. Rings treated with EPA were separated into three groups: E+ (intact endothelium), E- (endothelium stripped) and LNA E+ (pretreatment of E+ rings with l-nitro-arginine). Results: EPA, but not DHA, induced a significant and prolonged 25% drop in PVR (n = 8, p < 0.001). Incubation of vascular rings with EPA (100 µM) caused a maximum relaxation of 60% in the E+ (n = 6), whereas vessel tone did not change in the E- (n = 6, p < 0.001). The vascular effects of EPA were significantly decreased in LNA E+ (n = 6). Incubation with DHA resulted in only a mild relaxation at the highest concentration of DHA (300 µM) compared to E+. Conclusions: EPA induces a sustained pulmonary vasodilatation in fetal lambs. This effect is endothelium- and dose-dependent and involves nitric oxide (NO) production. We speculate that EPA supplementation may improve pulmonary circulation in clinical conditions with PPHN.

Benefits of Delayed Cord Clamping in Red Blood Cell Alloimmunization.

BACKGROUND AND OBJECTIVE: Several studies have shown the benefits of delayed cord clamping (DCC) in preterm and in healthy newborns at short and long term. Our objective was to evaluate the potentials benefits and risks of DCC in red cell alloimmunization. METHODS: This was a comparative before/after study of all living born neonates followed after fetal anemia requiring in utero transfusion. DCC was defined as cord clamping 30 seconds after birth. RESULTS: We included a continuous series of 72 neonates: 36 without DDC (group 1) and 36 with DDC (group 2). Hemoglobin at birth was lower in group 1 (10.2 vs 13.4 g/dL, P = .0003); 7 (25%) neonates in group 1 vs 24 (70.6%) in group 2 had no anemia at birth (P = .004). The rate of transfusion was similar between the 2 groups. Postnatal exchange transfusions were more likely performed in the group without DCC than in the group with DCC (47.2% vs 19.4%, P = .0124). Delay between birth and first transfusion was higher in group 2 (0 [0-13] vs 1 [0-21], P = .0274). The maximum level of bilirubin, the rate of intensive phototherapy, and the total duration of phototherapy were similar in the 2 groups. CONCLUSIONS: This study highlights a significant benefit of DCC in anemia secondary to red blood cell alloimmunization with a resulting decreased postnatal exchange transfusion needs, an improvement in the hemoglobin level at birth and longer delay between birth and first transfusion with no severe hyperbilirubinemia.

Maternal PUFA ω-3 Supplementation Prevents Neonatal Lung Injuries Induced by Hyperoxia in Newborn Rats.

Bronchopulmonary dysplasia (BPD) is one of the most common complications of prematurity, occurring in 30% of very low birth weight infants. The benefits of dietary intake of polyunsaturated fatty acids ω-3 (PUFA ω-3) during pregnancy or the perinatal period have been reported. The aim of this study was to assess the effects of maternal PUFA ω-3 supplementation on lung injuries in newborn rats exposed to prolonged hyperoxia. Pregnant female Wistar rats (n = 14) were fed a control diet (n = 2), a PUFA ω-6 diet (n = 6), or a PUFA ω-3 diet (n = 6), starting with the 14th gestation day. At Day 1, female and newborn rats (10 per female) were exposed to hyperoxia (O2, n = 70) or to the ambient air (Air, n = 70). Six groups of newborns rats were obtained: PUFA ω-6/O2 (n = 30), PUFA ω-6/air (n = 30), PUFA ω-3/O2 (n = 30), PUFA ω-3/air (n = 30), control/O2 (n = 10), and control/air (n = 10). After 10 days, lungs were removed for analysis of alveolarization and pulmonary vascular development. Survival rate was 100%. Hyperoxia reduced alveolarization and increased pulmonary vascular wall thickness in both control (n = 20) and PUFA ω-6 groups (n = 60). Maternal PUFA ω-3 supplementation prevented the decrease in alveolarization caused by hyperoxia (n = 30) compared to PUFA ω-6/O2 (n = 30) or to the control/O2 (n = 10), but did not significantly increase the thickness of the lung vascular wall. Therefore, maternal PUFA ω-3 supplementation may protect newborn rats from lung injuries induced by hyperoxia. In clinical settings, maternal PUFA ω-3 supplementation during pregnancy and during lactation may prevent BPD development after premature birth.

Electro-stimulation in preterm neonates with congenital auriculo-ventricular block. Report of three cases.

UNLABELLED: Congenital auriculo-ventricular blocks (CAVB) are usually linked to maternal auto-immune diseases and their management remains controversial. We report three cases of CAVB in preterm newborns managed using electro-stimulation with an external, followed by an internal pacemaker. Results and long-term follow-up were satisfactory in all three children. CONCLUSION: the transitory placement of an external pacemaker seems necessary in low birth weight infants in order to allow weight gain and therefore the insertion of a permanent pacemaker. The prognosis seems good but a regular echocardiographic surveillance is of great importance in order to detect the onset of cardiac failure secondary to dilated cardiomyopathy.