Latency duration of preterm premature rupture of membranes and neonatal outcome: a retrospective single-center experience.

In preterm premature rupture of membranes (PPROM), a decision between early delivery with prematurity complications and pregnancy prolongation bearing the risk of chorioamnionitis has to be made. To define disadvantages of delayed prolongation, latency duration of PPROM in expectantly managed pregnancies was investigated. We included those PPROMs > 48 h leading to preterm birth prior 37 weeks' gestation and retrospectively analyzed 84 preterm infants fulfilling these criteria. The association between latency duration/appearance of PPROM and respiratory outcome (primary outcomes) and neurological outcome (secondary outcomes) was investigated. The study showed that latency duration of PPROM is not associated with clinical or histological chorioamnionitis (p = 0.275; p = 0.332). As the numerous clinical parameters show multicollinearity between each other, we performed a multiple regression analysis to consider this fact. Respiratory distress syndrome is significantly associated with gestational age at PPROM (p < 0.001), and surfactant application is significantly associated with PPROM duration (p = 0.014). The other respiratory parameters including steroids and diuretics therapy, bronchopulmonary dysplasia, and the neurological parameters (intraventricular hemorrhage, Bayley II testing at a corrected age of 24 months) were not significantly associated with PPROM duration or gestational age at PPROM diagnosis.Conclusion: Latency duration of PPROM was not associated with adverse neonatal outcome in expectantly and carefully managed pregnancies, but respiratory distress syndrome was pronounced. The observed effect of pronounced respiratory distress syndrome can be treated with surfactant preparations and was not followed by increased rate of bronchopulmonary dysplasia. What is Known: • In case of preterm premature rupture of membranes, a decision between pregnancy prolongation with the risk of chorioamnionitis and early delivery with prematurity complications has to be made. • Chorioamnionitis is a dangerous situation for the pregnant woman and the fetus. • Impaired neurodevelopmental outcome is strongly correlated with pronounced prematurity due to the increased rate of serious complications. What is New: • Respiratory distress syndrome is significantly associated with gestational age at PPROM, and surfactant application is significantly associated with PPROM duration. • Latency duration of PPROM is not associated with adverse respiratory neonatal outcome (therapy with continuous positive airway pressure, therapy with diuretics and/or steroids, bronchopulmonary dysplasia) in expectantly and carefully managed pregnancies. • Intraventricular hemorrhage and Bayley II testing at a corrected age of 24 months are not associated with latency duration of PPROM when pregnancies are carefully observed.

DMBT1 is upregulated in lung epithelial cells after hypoxia and changes surfactant ultrastructure.

BACKGROUND: Hypoxia and asphyxia are known to induce surfactant inactivation in newborns. Deleted in Malignant Brain Tumors 1 (DMBT1) is an innate immunity protein with functions in epithelial differentiation and angiogenesis. It was detected in hyaline membranes of infants with respiratory distress syndrome. Human recombinant DMBT1 is able to increase the surface tension of exogenous surfactant preparations in a dose-dependent manner. METHODS: Immunohistochemistry was performed on lung sections of infants who died due to pre-, peri- or postnatal hypoxia. The lung epithelial cell line A549 was stably transfected with a DMBT1 (DMBT1+ cells) expression plasmid or with an empty plasmid (DMBT1- cells). The cells were cultured in normoxic or hypoxic conditions, and then DMBT1 as well as HIF-1α RNA expression were analyzed by using real-time-polymerase chain reaction. Human recombinant DMBT1 was added to the modified porcine natural surfactant Curosurf to examine the effect of DMBT1 on surfactant ultrastructure with electron microscopy. RESULTS: DMBT1 expression was upregulated in human lung tissue after fetal/peri-/postnatal hypoxia. In addition, in vitro experiments showed increased DMBT1 RNA expression in A549 cells after hypoxia. HIF-1α was upregulated in both DMBT1+ and DMBT1- cells in response to hypoxia. The addition of human recombinant DMBT1 to Curosurf caused an impaired surfactant ultrastructure. CONCLUSIONS: DMBT1 is upregulated in response to hypoxia and there seems to be a link between hypoxia and surfactant inactivation.

Neurological outcome at 24 months corrected age of prematurely born infants after preterm premature rupture of membranes (PPROM) of at least 7 days: a two-center experience in Germany.

Objective: Preterm premature rupture of membranes (PPROM) is a risk factor for chorioamnionitis (CA) and injury to the fetal brain. However, prolongation of gestation prevents morbidity and decreases complications of prematurity. The current investigation is to define risk factors for the adverse neurological outcome from the influence of PPROM of at least 7 days.Methods: A case-control study included three groups of preterm infants born at the University Hospitals Bonn and Essen, Germany. The first group consisted of infants with PPROM of at least 7 days and no chorioamnionitis (CA) (PPROM group), the second included preterm infants with CA (CA group), and the third group consisted of infants without PPROM and CA (control group). The outcome was assessed using Bayley Scales of Infant Development at a corrected age of 24 months. Each group consisted of 20 corresponding infants with an identical birth weight and gestational age at birth.Results: There was no significant difference between the mental development index (MDI) and psychomotor development index (PDI) scores (mean ± SD): the MDI score was 101 ± 14 in the PPROM group, 98 ± 12 in the CA group and 96 ± 17 in the control group; the PDI score 96 ± 10, 89 ± 16, and 90 ± 17, respectively. Multiple regression analysis revealed no significant influence of PPROM and CA on neurological outcome.Conclusions: PPROM of at least 7 days has no influence on neurodevelopmental outcome at a corrected age of 24 months when birth is initiated in the case of beginning CA.