Association Between Maternal 2nd Trimester Plasma Folate Levels and Infant Bronchiolitis.

Objectives Viral bronchiolitis is the most common cause of infant hospitalization. Folic acid supplementation is important during the periconceptional period to prevent neural tube defects. An area of investigation is whether higher prenatal folate is a risk factor for childhood respiratory illnesses. We investigated the association between maternal 2nd trimester plasma folate levels and infant bronchiolitis. Methods We conducted a retrospective cohort analysis in a subset of mother-infant dyads (n = 676) enrolled in the Conditions Affecting Neurocognitive Development and Learning in Early Childhood study and Tennessee Medicaid. Maternal folate status was determined using 2nd trimester (16-28 weeks) plasma samples. Bronchiolitis diagnosis in the first year of life was ascertained using International Classification of Diagnosis-9 codes from Medicaid administrative data. We used multivariable logistic regression to assess the adjusted association of prenatal folate levels and infant bronchiolitis outcome. Results Half of the women in this lower-income and predominately African-American (84%) study population had high levels of folate (median 2nd trimester level 19.2 ng/mL) and 21% of infants had at least one bronchiolitis healthcare visit. A relationship initially positive then reversing between maternal plasma folate and infant bronchiolitis was observed that did not reach statistical significance (poverall = .112, pnonlinear effect = .088). Additional adjustment for dietary methyl donor intake did not significantly alter the association. Conclusions for Practice Results did not confirm a statistically significant association between maternal 2nd trimester plasma folate levels and infant bronchiolitis. Further work is needed to investigate the role of folate, particularly higher levels, in association with early childhood respiratory illnesses.

Effectiveness of Respiratory Syncytial Virus Immunoprophylaxis in Reducing Bronchiolitis Hospitalizations Among High-Risk Infants.

We sought to determine the real-world effectiveness of respiratory syncytial virus (RSV) immunoprophylaxis in a population-based cohort to inform policy. The study population included infants born during 1996-2008 and enrolled in the Kaiser Permanente Northern California integrated health-care delivery system. During the RSV season (November-March), the date of RSV immunoprophylaxis administration and the following 30 days were defined as RSV immunoprophylaxis protected period(s), and all other days were defined as unprotected period(s). Numbers of bronchiolitis hospitalizations were determined using International Classification of Diseases, Ninth Revision, codes during RSV season. We used a proportional hazards model to estimate risk of bronchiolitis hospitalization when comparing infants' protected period(s) with unprotected period(s). Infants who had ever received RSV immunoprophylaxis had a 32% decreased risk of bronchiolitis hospitalization (adjusted hazard ratio = 0.68, 95% confidence interval: 0.46, 1.00) when protected periods were compared with unprotected periods. Infants with chronic lung disease (CLD) had a 52% decreased risk of bronchiolitis hospitalization (adjusted hazard ratio = 0.48, 95% confidence interval: 0.25, 0.94) when protected periods were compared with unprotected periods. Under the new 2014 American Academy of Pediatrics (AAP) guidelines, 48% of infants eligible for RSV immunoprophylaxis on the basis of AAP guidelines in place at birth would no longer be eligible, but nearly all infants with CLD would remain eligible. RSV immunoprophylaxis is effective in decreasing hospitalization. This association is greatest for infants with CLD, a group still recommended for receipt of RSV immunoprophylaxis under the new AAP guidelines.

Maternal Folic Acid Supplementation During Pregnancy and Early Childhood Asthma.

BACKGROUND: Asthma is one of the most common chronic childhood diseases. While folic acid supplementation around conception helps prevent neural tube defects, an animal model suggests that it may be a risk factor for respiratory diseases, although epidemiologic studies have had conflicting results. We investigated the timing of folic acid-containing prescription filling during pregnancy and child asthma. METHODS: In a retrospective cohort study of 104,428 children, born 1996-2005, and their mothers enrolled in Tennessee Medicaid, we investigated the association of filling folic acid-containing prescriptions during pregnancy and childhood asthma at ages 4.5-6 years. We categorized women into exposure groups based on prescription filling centered around the first trimester: no folic acid prescription exposure, exposure in first trimester only, exposure after first trimester, and exposure in first trimester and beyond. We defined asthma using asthma-specific healthcare visits and medication fills. Using logistic regression models, we investigated the relationship adjusting for potential confounders. RESULTS: Overall 15% of children had asthma. Compared with children born to women with no folic acid prescription exposure, children born to women with exposures in the first trimester only or first trimester and later had increased relative odds of asthma (adjusted odds ratios = 1.2, 95% confidence interval = 1.1, 1.3, and 1.2, 95% confidence interval = 1.2, 1.3); no association was seen in children born to women exposed after the first trimester. CONCLUSION: Timing of folic acid-containing prescription filling during pregnancy was associated with childhood asthma. Our findings contribute to understanding of the role of prenatal nutritional supplements on child respiratory health.

Association of folic acid supplementation during pregnancy and infant bronchiolitis.

Viral bronchiolitis affects 20%-30% of infants; because there is no known effective treatment, it is important to identify risk factors that contribute to its pathogenesis. Although adequate folate intake during the periconceptional period prevents neural tube defects, animal data suggest that higher supplementation may be a risk factor for child respiratory diseases. Using a population-based retrospective cohort of 167,333 women and infants, born in 1995-2007 and enrolled in the Tennessee Medicaid program, we investigated the association between the filling of folic acid-containing prescriptions and infant bronchiolitis. We categorized women into the following 4 groups in relation to the first trimester: "none" (no prescription filled), "first trimester only," "after first trimester," and "both" (prescriptions filled both during and after the first trimester). Overall, 21% of infants had a bronchiolitis diagnosis, and 5% were hospitalized. Most women filled their first prescriptions after the fifth to sixth weeks of pregnancy, and most prescriptions contained 1,000 µg of folic acid. Compared with infants born to women in the "none" group, infants born to women in the "first trimester only" group had higher relative odds of bronchiolitis diagnosis (adjusted odds ratio = 1.17, 95% confidence interval: 1.11, 1.22) and greater severity (adjusted odds ratio = 1.16, 95% confidence interval: 1.11, 1.22). This study's findings contribute to an understanding of the implications of prenatal nutritional supplement recommendations for infant bronchiolitis.