The data set, “The Matched Multiple Birth File,” assembled by the National Center for Health Statistics (NCHS) was used for this analysis. This data set includes U.S. live births and fetal deaths among twins and higher order multiples for the years 1995 through 1998. The completeness of this file is excellent (99%), and the procedures [...]

INTRODUCTION
The neonatal period is very critical for infant survival and development. The increased vulnerability of the neonate is responsible for its lower survival threshold as compared to postneonates. In general, neonatal mortality rates are about twice the post-neonatal rates for nearly all racial/ethnic groups. Twin neonates are even more vulnerable than singletons. National rates of [...]

The precise pathogenesis of myocarditis is unknown. Available evidence suggest a multifactorial process involving direct cell damage, autoimmunity and microvascular spasms with vascular damage.

Myocarditis refers to an inflammatory disease of the myocardium. The process may be focal or diffuse and is associated with cardiac dysfunction. Myocarditis may exist with or without pericardial involvement.

This study confirms previous reports of rates of asthma during pregnancy in the range of 0.4% to 1.3% (Table 2). It also demonstrates that rates of asthma during pregnancy are racially disparate, with African Americans and Hispanics at greater risk than whites. Furthermore, women with Medicaid and Medicaid Healthstart are at greater risk for asthma [...]

Descriptive Characteristics of the Study Population
Only the racial/ethnic groups of non-Hispanic whites (n=337,130), non-Hispanic African Americans (n= 102,129), and Hispanics (n=80,898) were used for the analyses presented in this report. Those with other race/ethnicity (n=36,440,6.6% of the study population) were excluded from the analyses because of their heterogeneity. The characteristics of the study population are [...]

The methods used have been described in part elsewhere but are summarized here. The data for this historical cohort study were obtained from an administrative database that contains linked birth certificate, infant death certificate, and maternal and newborn hospital discharge claims data for the delivery hospitalization for all singleton, live births to New Jersey residents [...]