Placental inflammation is associated with rural and remote residence in the Northern Territory, Australia: a cross-sectional study.

BACKGROUND: The Northern Territory has the highest rates of perinatal morbidity and mortality in Australia. Placental histopathology has not been studied in this high-risk group of women. METHODS: This is the first study to detail the placental pathology in Indigenous women and to compare the findings with non-Indigenous women in the Northern Territory. There were a total of 269 deliveries during a three-month period from the 27(th) of June to the 27(th) of August 2009. Seventy-one (71%) percent of all placentas were examined macroscopically, sectioned then reviewed by a Perinatal Pathologist, blinded to the maternal history and outcomes. RESULTS: Indigenous women were found to have higher rates of histologically confirmed chorioamnionitis and or a fetal inflammatory response compared with non-Indigenous women (46% versus 26%; OR 2.4, 95% CI 1.3-4.5). In contrast, non-Indigenous women were twice as likely to show vascular related pathology (31% versus 14%; OR 2.77, 95% CI 1.3-5.9). Indigenous women had significantly higher rates of potentially modifiable risk factors for placental inflammation including genitourinary infections, anaemia and smoking. After adjusting for confounders, histological chorioamnionitis and fetal inflammatory response was significantly associated with rural or remote residence (Adjusted OR 2.5, 95% CI 1.08 - 5.8). CONCLUSION: This study has revealed a complex aetiology underlying a high prevalence of placental inflammation in the Northern Territory. Placental inflammation is associated with rural and remote residence, which may represent greater impact of systemic disadvantage, particularly affecting Indigenous women in the Northern Territory.

Prematurity, chorioamnionitis, and the development of recurrent wheezing: a prospective birth cohort study.

BACKGROUND: Prematurity (< 37 weeks) has been inconsistently associated with asthma and wheezing. Chorioamnionitis may promote both prematurity and inflammatory pathways in infants' airways. OBJECTIVE: To investigate the relationship of prematurity and chorioamnionitis with the development of early childhood recurrent wheezing. METHODS: The Boston Birth Cohort (n = 1096) were followed prospectively from birth to a mean age of 2.2 +/- 2 years. Perinatal and postnatal clinical data and placental pathology were collected. The primary outcome was recurrent wheezing (> or =2 physician documented episodes). Secondary outcomes included physician-diagnosed asthma, food allergy, and eczema. Preterm children were grouped by gestational age into moderately (33-36.9 weeks) and very preterm (< 33 weeks) with and without chorioamnionitis, and compared with term children without chorioamnionitis (reference group). Chorioamnionitis was diagnosed either by intrapartum fever or by placental histology findings. Logistic regression models were performed to investigate the independent and joint associations of degree of prematurity and chorioamnionitis. RESULTS: Prematurity was associated with recurrent wheezing (odds ratio [OR], 1.7; 95% CI, 1.2-2.6). However, when subjects were grouped by degree of prematurity with or without chorioamnionitis, the highest risk of wheezing (OR, 4.0; 95% CI, 2.0-8.0) and physician-diagnosed asthma (OR, 4.4; 95% CI, 2.2-8.7) was present in the very preterm children with chorioamnionitis. The effect on both wheezing (OR, 5.4; 95% CI, 2.4-12.0) and asthma (OR, 5.2; 95% CI, 2.3-11.9) was greater in African Americans. Neither prematurity nor chorioamnionitis was associated with food allergy or eczema. CONCLUSION: We found a strong joint effect of prematurity and chorioamnionitis on early childhood wheezing. This effect was stronger in African American subjects.

Histologic chorioamnionitis and preterm delivery.

Inconsistent findings linking placental histologic chorioamnionitis (HCA) and preterm delivery may result from variations in HCA definition, population studied, and exclusion criteria. This analysis from the 1998-2004 Pregnancy Outcomes and Community Health Study (five Michigan communities) includes the first 1,053 subcohort women (239 preterm, 814 term) with completed placental assessments. Multiple HCA definitions were constructed by 1) varying polymorphonuclear leukocytes/high-powered field thresholds and placenta components included and 2) using polymorphonuclear leukocyte characteristics to assign low/high maternal, fetal inflammation stage and grade. In African Americans, HCA was associated with preterm delivery before 35 weeks. The effect size was modest for polymorphonuclear leukocytes/high-powered field thresholds of greater than 10 and greater than 30 (odds ratios (ORs) = 0.8 and 2.0); larger for greater than 100 (OR = 3.2, 95% confidence interval (CI): 1.4, 7.1); strengthened after excluding medically indicated preterm deliveries (OR = 4.9, 95% CI: 2.0, 11.8); and strongest for high maternal/high fetal HCA (OR = 5.6, 95% CI: 1.4, 22.1). These latter HCA criteria also produced the largest effect size in Whites/others (OR = 2.7, 95% CI: 0.3, 26.9). Among preterm deliveries before 35 weeks excluding those medically indicated, 12% of Whites/others and 55% of African Americans had high maternal HCA. The authors conclude that HCA definition, exclusion criteria, and race/ethnicity influence the HCA-preterm delivery association and that HCA contributes to preterm delivery-related ethnic disparity.

Hyperglycemia in extremely low birth weight infants in a predominantly Hispanic population and related morbidities.

OBJECTIVE: This study describes the incidence, correlates and subsequent morbidities of hyperglycemia, a highly prevalent condition in extremely low birth weight (ELBW) infants. STUDY DESIGN: A retrospective chart review of 169 infants with birth weight (BW)<1000 g was conducted. Hyperglycemia was defined as plasma glucose level > or =150 mg/dl during the first 2 weeks of life. Data were analyzed by logistic regression, multivariate analysis and Fisher exact test. RESULTS: Overall, 88% of the study sample developed hyperglycemia in the first 2 weeks of life. Both gestational age (GA) (odds ratio (OR) 0.11, 95% confidence interval (CI)=0.01-0.89) and chorioamnionitis (OR 0.10, 95% CI=0.01-0.64) were inversely associated with hyperglycemia, whereas BW, sepsis and postnatal steroid exposure were not. After adjusting for GA, BW and postnatal steroids, hyperglycemia was associated with a statistically significant increase in retinopathy of prematurity (ROP) (OR 4.6, 95% CI 1.12-18.9). No association was found with bronchopulmonary dysplasia, intraventricular hemorrhage, death or prolonged hospital stay. CONCLUSION: Lower GA was identified as the main factor associated with hyperglycemia in ELBW infants during the first 2 weeks of life. Hyperglycemia was associated with an increased incidence of ROP; further studies need to determine if this association is causal.

Preterm delivery and perinatal death among black and white infants in a Chicago-area perinatal registry.

OBJECTIVE: To explore associations between race, preterm delivery, etiologic classification of preterm delivery, and perinatal mortality. METHODS: The study population consisted of 13,010 black and 19,007 white mother-infant pairs delivered at Chicago-area hospitals in 1988-1989 categorized as term or preterm births. Preterm births were further divided by severity and etiology. Black-white differences in perinatal mortality within groups were calculated and adjusted for birth weight and other potential confounding variables. RESULTS: Black women were nearly twice as likely as whites to experience preterm (before 37 weeks' gestation) and very preterm (before 32 weeks' gestation) delivery associated with premature rupture of membranes (PROM) or classified as idiopathic. Although black infants were also found to have twice the perinatal mortality risk of white infants (relative risk [RR] 2.1, 95% confidence interval [CI] 1.7-2.5), the overall preterm perinatal mortality rates did not differ between black and white women (RR 1.0, 95% CI 0.8-1.2). However, among preterm births, perinatal mortality was not uniform within categories of medical etiology. The mortality risk was the same for black and white infants born preterm following polyhydramnios or placental complications (RR 1.1, 95% CI 0.6-1.9), the same for black and white infants born preterm after labor induction (RR 1.1, 95% CI 0.6-1.9), and higher for black infants classified as idiopathic preterm deliveries (RR 1.6, 95% CI 1.1-2.3). In contrast, mortality rates tended to be lower for black infants born preterm following PROM-amnionitis (RR 0.8, 95% CI 0.5-1.2). The idiopathic disparity was explained by a differential birth weight distribution (adjusted RR 1.1, 95% CI 0.7-1.9); however, the apparent survival benefit among black infants born preterm following PROM increased even further after adjustment for birth weight (adjusted RR 0.4, 95% CI 0.2-0.7). CONCLUSION: Black infants born preterm after PROM appear to have a survival advantage compared with their white counterparts, an effect not observed within other etiologic categories of preterm delivery.

Race, perinatal outcome, and amniotic infection.

Racial differences in rates of amniotic infection were examined through a review of the literature. Following a computerized and manual search of the literature from 1966 to 1994, studies were selected that reported the prevalence by race of presumed markers of amniotic infection. These markers included: amniotic infection syndrome, histologic chorioamnionitis, clinical chorioamnionitis, premature rupture of the membranes, and early neonatal mortality from sepsis. With the exception of overall rates of histologic chorioamnionitis, black women showed higher rates of the all the conditions examined. Insofar as amniotic infection is a risk factor for poor perinatal outcomes, the finding of higher rates of markers of amniotic infection among black women suggests that such infections may contribute to racial disparities in perinatal outcome.