Identification of Iowa live births in the Agricultural Health Study.

In the Agricultural Health Study, information on participant live births was largely provided by female partners of male private applicators. At the Iowa site, such information was available for 13,599 (42.9%) of 31,707 applicators. To improve identification of live births among Iowa participants, we used a probabilistic and deterministic approach to link available demographic data from 31,707 households and information on live births from 13,599 households with 1,014,916 Iowa birth certificates. Record linkage identified 16,611 (93.7%) of 17,719 reported live births and 17,883 additional live births, most (14,411 or 80.6%) not reported due to nonresponse by female partners. This record linkage produced an expanded cohort of live-born children among Iowa participants, which will facilitate improved study of the effects of agricultural exposures, including pesticides, on selected birth outcomes and childhood disease.

Maternal reports of satisfaction with care and outcomes for children with craniosynostosis.

Craniosynostosis is a congenital deformity caused by premature fusion of cranial suture(s). Surgical outcomes of craniosynostosis have been well documented; however, limited published data are available regarding access to care and social and psychological health outcomes for children with craniosynostosis. The authors conducted a population-based, multistate study of maternal perceptions of care and outcomes for children with craniosynostosis born from January 1998 through December 2003. Mothers of 147 children were contacted and asked to complete a structured telephone interview; 82 mothers (55.8%) participated. Overall, the mean ages of children and their mothers at the time of interview were 4.4 and 34.8 years, respectively. Mothers interviewed tended to be white and, at a minimum, high school graduates. Most mothers reported being satisfied with the craniosynostosis-related information and support provided by medical care providers, and access to primary and specialty care was most often rated as satisfactory. Mothers tended to report the physical health of their child to be good; however, delays in cognitive and emotional development, hearing loss, and speech problems were identified. In addition, statistically significant differences among mothers in each state were noted for reports of the quality of team care, primary care, learning interventions, and perceived need for additional surgeries. These results suggest some limitations in craniosynostosis-related care and provide guidance to medical and surgical care providers in making need-based improvements in craniosynostosis surgery and care. Future studies are recommended to replicate this evaluation in additional populations.

Maternal periconceptional exposure to cigarette smoking and alcohol and esophageal atresia +/- tracheo-esophageal fistula.

BACKGROUND: Esophageal atresia (EA) is a moderately frequent birth defect that often occurs with tracheo-esophageal fistula (TEF). Etiologic studies for EA+/-TEF have produced inconsistent results. METHODS: This study used data from the National Birth Defects Prevention Study (NBDPS) to examine the association between maternal periconceptional exposure to cigarette smoking and alcohol and EA+/-TEF. Cases of EA+/-TEF and unaffected controls with an estimated date of delivery from October 1997 through December 2003 were identified, and telephone interview reports for smoking and alcohol exposure were obtained from birth mothers of 334 cases and 4,967 controls. Odds ratios (OR)s and 95% confidence intervals (CI)s, adjusted for several covariates, were calculated to assess associations. RESULTS: ORs were near unity for all EA+/-TEF cases combined and any periconceptional exposure to cigarette smoking (OR = 1.1; CI = 0.8,1.6) or alcohol (OR = 1.2; CI = 0.8,1.8). For cigarette smoking, some elevated ORs were found but varied by type of smoking exposure. No consistent patterns were identified for number of cigarettes smoked per day. For alcohol, ORs were weak to moderately elevated with increasing number of drinks consumed and for binge drinkers compared to non-binge drinkers. ORs were further elevated among mothers who reported active+passive exposure to cigarette smoking and alcohol (OR = 2.5; CI = 1.1,5.6). For both exposures, ORs were higher for cases with additional major defects compared to isolated cases. CONCLUSIONS: These results, based on one of the largest published samples of EA+/-TEF cases, suggest a role for these exposures in the etiology of EA+/-TEF, although further study is needed to replicate the observed associations.

Meta-analysis: pesticides and orofacial clefts.

OBJECTIVE: The risk of orofacial clefts associated with pesticide exposure was examined by conducting a meta-analysis of studies published from 1966 through 2005. DESIGN: The full text of 230 studies was reviewed in detail, and of these, 19 studies were included in the final analysis. Fixed effects and random effects models were used to calculate pooled odds ratios (ORs) and 95% confidence intervals (CIs), and homogeneity among studies was evaluated. MAIN OUTCOME MEASURES: Exposure- and phenotype-specific risks associated with pesticides. RESULTS: Many of the studies identified as suitable for analysis used a retrospective design with varying sample sizes, levels of exposure assessment, and phenotype evaluation. For all phenotypes combined, maternal occupational exposure was associated with an increased risk of clefting (OR=1.37; CI=1.04 to 1.81), whereas the estimates were somewhat weaker for paternal occupational exposures (OR=1.16; CI=0.94 to 1.44) or for any residential exposure (OR=0.77; CI=0.20 to 2.96). Calculation of pooled estimates for individual cleft phenotypes was mostly limited to studies of paternal occupational exposure; estimates exceeded unity but were not statistically significant. CONCLUSIONS: The results of this meta-analysis suggest that maternal exposure to pesticides is associated with a modest but marginally significant risk of clefting. To better understand the relationship between pesticide exposure and orofacial clefts, future studies should consider evaluation of multiple routes of parental exposure, etiologically homogenous phenotypes, and individual genetic susceptibility.

Microcirculatory effects of pulsed electromagnetic fields.

PURPOSE: Pulsed electromagnetic fields (PEMF) are used clinically to expedite healing of fracture non-unions, however, the mechanism of action by which PEMF stimulation is effective is unknown. The current study examined the acute effects of PEMF stimulation on arteriolar microvessel diameters in the rat cremaster muscle. The study hypothesis was that PEMF would increase arteriolar diameters, a potential mechanism involved in the healing process. METHODS: Local PEMF stimulation/sham stimulation of 2 or 60 min duration was delivered to the cremaster muscle of anesthetized rats. Arteriolar diameters were measured before and after stimulation/sham stimulation using intravital microscopy. Systemic hemodynamics also were monitored during PEMF stimulation. RESULTS: Local PEMF stimulation produced significant (p<0.001) vasodilation, compared to pre-stimulation values, in cremasteric arterioles in anesthetized rats (n=24). This dilation occurred after 2 min of stimulation (9% diameter increase) and after 1 h of stimulation (8.7% diameter increase). Rats receiving "sham" stimulation (n=15) demonstrated no statistically significant change in arteriolar diameter following either "sham" stimulation period. PEMF stimulation of the cremaster (n=4 rats) did not affect systemic arterial pressure or heart rate, nor was it associated with a change in tissue environmental temperature. CONCLUSIONS: These results support the hypothesis that local application of a specific PEMF waveform can elicit significant arteriolar vasodilation. Systemic hemodynamics and environmental temperature could not account for the observed microvascular responses.