Asthma During Pregnancy: Racial Disparities in Birth Outcome

Purpose: The disparity in birth outcomes among different racial groups in the US has not dissipated. In 2003 Black infants were twice as likely to die during the first year compared to White infants. Asthma during pregnancy is associated with an increased risk of poor maternal and neonatal outcomes. Approximately 6% of pregnant women have asthma in the US. Women who are treated for asthma during pregnancy have similar outcomes to non-asthmatic women. Poor asthma control can result in a variety of adverse outcomes for both mother and child. Studies interrogating the link between asthma during pregnancy and poor birth outcome across racial/ethnic groups are lacking. The research questions for this study are: 1) What is the prevalence of asthma among a sample of mother-infant dyads? 2) What is the association between race/ethnicity and birth outcomes, asthma diagnosis, and asthma medication use? 3) Is the relationship between asthma and birth outcomes mediated by race/ethnicity?

Method: This study will utilize secondary data to analyze asthma and birth outcome by race in an Upstate New York city. A mother-infant linked dataset that included information for all singleton deliveries (N=2829) in a large hospital between 2000 and 2002 was utilized. Bivariate analyses were used to: 1) explore the relationship between low birthweight, preterm birth, Small for Gestational Age (SGA), Full Term Intrauterine Growth Restriction (FT-IUGR), and race/ethnicity; 2) explore the association between asthma diagnosis and asthma medication use by race/ethnicity; and 3) examine the association between asthma diagnosis and birth outcome by race/ethnicity.

Results: The pregnancy asthma rate (12%) was twice as high as the US rate (6%). The relationship between race/ethnicity and the birth outcomes were statistically significant with the exception of FT-IUGR. Overall, Black and Hispanic women were more likely to have a low birthweight, preterm, or SGA infant compared to White women. Reported asthma was highest among Hispanic women compared to White and Black women (16.5%, 12.9%, and 11.1%, respectively). Among asthmatic women half (51.2%) were taking asthma medications. Hispanic asthmatic women were least likely to be receiving asthma medication (43.8%). Interestingly, Black and White women with asthma had more favorable low birthweight and preterm rates compared to Black and White non-asthmatic women. Conversely, Hispanic asthmatics had the highest rate of preterm birth than other racial/ethnic groups. Black asthmatic women had a greater prevalence of SGA and FT-IUGR infants than their non-asthmatic counterparts.

Implications: This work contributes to the gap in our understanding of the connections between asthma and birth outcomes for racial/ethnic groups. There has been a dearth of research examining the link between asthma during pregnancy and birth outcome among minority populations, and most research on asthma has focused on children. Hispanics are more likely than any other group in the US to be uninsured. Our study found that they had the highest asthma rate, the lowest asthma medication use, and the highest preterm rate. Health care providers and social workers must work together to ensure that asthmatic women who lack health insurance obtain early, quality prenatal care.