Linda Van Marter | Harvard Medical School (original) (raw)

Papers by Linda Van Marter

International Journal of Pediatrics, 2014

Aim. To determine among infants born before the 28th week of gestation to what extent blood gas a... more Aim. To determine among infants born before the 28th week of gestation to what extent blood gas abnormalities during the first three postnatal days provide information about the risk of bronchopulmonary dysplasia (BPD). Methods. We studied the association of extreme quartiles of blood gas measurements (hypoxemia, hyperoxemia, hypocapnea, and hypercapnea) in the first three postnatal days, with bronchopulmonary dysplasia, among 906 newborns, using multivariable models adjusting for potential confounders. We approximated NIH criteria by classifying severity of BPD on the basis of the receipt of any O2 on postnatal day 28 and at 36 weeks PMA and assisted ventilation. Results. In models that did not adjust for ventilation, hypoxemia was associated with increased risk of severe BPD and very severe BPD, while infants who had hypercapnea were at increased risk of very severe BPD only. In contrast, infants who had hypocapnea were at reduced risk of severe BPD. Including ventilation for 14 or more days eliminated the associations with hypoxemia and with hypercapnea and made the decreased risk of very severe BPD statistically significant. Conclusions. Among ELGANs, recurrent/persistent blood gas abnormalities in the first three postnatal days convey information about the risk of severe and very severe BPD.

Pediatric Research, 2014

Clinical Investigation nature publishing group background: Risk factors for maternal vitamin D de... more Clinical Investigation nature publishing group background: Risk factors for maternal vitamin D deficiency and preterm birth overlap, but the distribution of 25-hydroxyvitamin D (25(OH)D) levels among preterm infants is not known. We aimed to determine the associations between 25(OH)D levels and gestational age. Methods: We measured umbilical cord plasma levels of 25(OH)D from 471 infants born at Brigham and Women's Hospital in Boston. We used generalized estimating equations to determine whether preterm (<37 wks' gestation) or very preterm (<32 wks' gestation) infants had greater odds of having 25(OH)D levels below 20 ng/ml than more mature infants. We adjusted for potential confounding by season of birth, maternal age, race, marital status, and singleton or multiple gestation. results: Mean cord plasma 25(OH)D level was 34.0 ng/ml (range: 4.1-95.3 and SD: 14.1). Infants born before 32 wks' gestation had increased odds of having 25(OH)D levels below 20 ng/ ml in unadjusted (odds ratio (OR): 2.2; 95% confidence interval (CI): 1.1-4.3) and adjusted models (OR: 2.4; 95% CI: 1.2-5.3) as compared with more mature infants. conclusion: Infants born in <32 wks' gestation are at higher risk than more mature infants for low 25(OH)D levels. Further investigation of the relationships between low 25(OH)D levels and preterm birth and its sequelae is thus warranted.

The Journal of Pediatrics, 2002

CLD Chronic lung disease rence of CLD is influenced by both antenatal and postnatal phenomena. 2,... more CLD Chronic lung disease rence of CLD is influenced by both antenatal and postnatal phenomena. 2,3 Antenatal infection and/or inflammation reduces the risk of surfactant defi-Objective: This case-control study of chronic lung disease (CLD) evaluated the hypothesis that chorioamnionitis promotes CLD and interacts with other risk factors for CLD, including mechanical ventilation and postnatal infection.

The Journal of Pediatrics, 2014

Necrotizing enterocolitis, characterized by sudden onset and rapid progression, remains the most ... more Necrotizing enterocolitis, characterized by sudden onset and rapid progression, remains the most significant gastrointestinal disorder among premature infants. In seeking a predictive biomarker, we found intestinal fatty acid binding protein, an indicator of enterocyte damage, was substantially increased within three and seven days before the diagnosis of necrotizing enterocolitis. (J Pediatr 2014;164:1486-8).

Developmental Medicine and Child Neurology, 2002

This study was designed to test the hypothesis that systemic hypotension during the first postnat... more This study was designed to test the hypothesis that systemic hypotension during the first postnatal week increases the risk of ultrasonographic echolucency in the white matter of preterm infants (≤28 weeks' gestation) while adjusting for confounders. From a study base of 1607 very-low-birthweight neonates (500 to 1500 g), a subsample of 243 preterm infants (122 females; ≤28 weeks' gestation) was selected for echolucency and data collection prospectively for the entire first postnatal week. Data analyses were performed separately for the first 24 hours of life, for the interval from the end of the first 24 hours to the end of the fourth postnatal day, and for days 5, 6, and 7. Systemic hypotension was defined as the mean arterial blood pressure in the lowest quartile for the infant's week of gestational age. Protocol cranial ultrasounds were those obtained closest to days 1, 7, and 21. A committee of sonologists classified the infants as having either echolucency (echolucency group) or not (control group). Systemic hypotension during the first week of life appeared to be associated with echolucency in univariable analyses but the association did not persist after adjustment for potential confounders. Detailed summaries of 13 previous studies, the majority of which did not show an association between systemic hypotension and white-matter damage, are presented. In sum, these results do not support the hypothesis that systemic hypotension contributes to echolucency among preterm infants.

Cytokine, 2001

To establish levels of mediators of inflammation in cord blood and postnatal serum from extremely... more To establish levels of mediators of inflammation in cord blood and postnatal serum from extremely low gestational age newborns (ELGANs, c28 weeks), we measured sixteen markers of inflammation by recycling immunoaffinity chromatography in 15 ELGANs who had serum sampled at days 2-5. Median levels of IL-1, IL-6, IL-8, IL-11, IL-13, TNF-, G-CSF, M-CSF, GM-CSF, MIP-1 , and RANTES were considerably higher than published values of these inflammatory mediators from term newborns. In three of eight ELGANS who had serial measurements taken, levels of IL-1, IL-6, IL-8, IL-11, TNF-, G-CSF, and MIP-1 declined from initially very high levels to reach an apparent baseline towards the end of the first postnatal week. In these same three infants, GM-CSF and TGF-1 levels increased continuously during the first week. In the other five ELGANs, no consistent changes were observed. We speculate, that in some ELGANs, a fetal systemic inflammatory response is characterized by an antenatal wave of pro-inflammatory cytokines, followed by a second, postnatal wave of anti-inflammatory cytokines. Large epidemiologic studies are needed to clarify relationships among inflammation markers and their expression in the fetal and neonatal circulation over time. Such studies would also add to our understanding of the possible role of inflammatory mediators in the pathophysiology of the major complications of extreme prematurity.

Archives of Disease in Childhood - Fetal and Neonatal Edition, 2011

To evaluate the relationships among cerebral palsy (CP) phenotypes and bronchopulmonary dysplasia... more To evaluate the relationships among cerebral palsy (CP) phenotypes and bronchopulmonary dysplasia (BPD) severity and, in the process, to generate hypotheses regarding causal pathways linking BPD to CP. We studied 1047 infants born before the 28th week of gestation. Receipt of supplemental oxygen at 36 weeks postmenstrual age (PMA), with or without the need for mechanical ventilation (MV) at 36 weeks PMA, defined two levels of BPD. At 24 months, the children underwent neurologic examinations and CP diagnoses were made using an algorithm based on topographic localisation. The 536 infants with BPD were at increased risk of all three CP phenotypes. In time-oriented multivariable analyses that adjusted for potential confounders, receipt of supplemental oxygen without MV at 36 weeks PMA (BPD) was not associated with increased risk of any CP phenotype. In contrast, BPD accompanied by MV at 36 weeks PMA (BPD/MV) was associated with a nearly sixfold increased risk of quadriparesis and a fourfold increased risk of diparesis. Combined treatment with both MV and supplemental oxygen at 36 weeks PMA strongly predicts the more common bilateral CP phenotypes. BPD without MV at 36 weeks PMA was not significantly associated with any form of CP.

American Journal of Obstetrics and Gynecology, 1999

This study was undertaken to determine whether very-low-birth-weight infants whose mothers receiv... more This study was undertaken to determine whether very-low-birth-weight infants whose mothers received a course of antenatal corticosteroids were at decreased risk for 3 cranial ultrasonographic entities that predict neurodevelopmental dysfunction. This retrospective cohort study evaluated 1604 infants weighing 500 to 1500 g who underwent >/=1 of 3 cranial ultrasonographic scans required by design at specified postnatal intervals and whose own and mother's hospital charts were reviewed. Infants were classified according to mother's course of antenatal corticosteroids (none, partial, or complete). In the total sample the risks of intraventricular hemorrhage and of an echolucent image in the cerebral white matter were only modestly (and not statistically significantly) reduced after a full course of antenatal corticosteroids, whereas antenatal corticosteroids appeared to significantly reduce the risk of ventriculomegaly after even a partial course. Antenatal corticosteroids appeared to halve the risk of ventriculomegaly and echolucent image among the gestationally youngest infants and those with intraventricular hemorrhage, hypothyroxinemia, or vasculitis of the umbilical cord or chorionic plate of the placenta. These observations are consistent with the hypothesis that antenatal corticosteroids protect very-low-birth-weight infants, especially those who are most vulnerable, against the risk of cranial ultrasonographic abnormalities.

Genome biology, Oct 4, 2007

Background: One-third to one-half of all infants born before the 28th week of gestation develop b... more Background: One-third to one-half of all infants born before the 28th week of gestation develop bronchopulmonary dysplasia (BPD). Inflammatory regulators appear to be involved in the pathogenesis of BPD, possibly beginning in fetal life. To evaluate the feasibility of using expression profiling in umbilical cord tissue to discover molecular signatures for developmental staging and for determining risk of BPD, we conducted a cross-sectional study of infants born at less than 28 weeks of gestation (n= 54). Sections of ...

OBJECTIVE.The goals were to identify the blood pressures of extremely low gesta- tional age newbo... more OBJECTIVE.The goals were to identify the blood pressures of extremely low gesta- tional age newborns that prompt intervention, to identify other infant character- istics associated with receipt of therapies intended to increase blood pressure, and to assess the interinstitutional variability in the use of these therapies. METHODS.The cohort included 1507 extremely low gestational age newborns born at 23 weeks to