Mediation analysis of gestational age, congenital heart defects, and infant birth-weight.

Abstract

BACKGROUND:

In this study we assessed the mediation role of the gestational age on the effect of the infant's congenital heart defects (CHD) on birth-weight.

METHODS:

We used secondary data from the Baltimore-Washington Infant Study (1981-1989). Mediation analysis was employed to investigate whether gestational age acted as a mediator of the association between CHD and reduced birth-weight. We estimated the mediated effect, the mediation proportion, and their corresponding 95% confidence intervals (CI) using several methods.

RESULTS:

There were 3362 CHD cases and 3564 controls in the dataset with mean birth-weight of 3071 (SD = 729) and 3353 (SD = 603) grams, respectively; the mean gestational age was 38.9 (SD = 2.7) and 39.6 (SD = 2.2) weeks, respectively. After adjusting for covariates, the estimated mediated effect by gestational age was 113.5 grams (95% CI, 92.4-134.2) and the mediation proportion was 40.7% (95% CI, 34.7%-46.6%), using the bootstrap approach.

CONCLUSIONS:

Gestational age may account for about 41% of the overall effect of heart defects on reduced infant birth-weight. Improved prenatal care and other public health efforts that promote full term delivery, particularly targeting high-risk families and mothers known to be carrying a fetus with CHD, may therefore be expected to improve the birth-weight of these infants and their long term health.

• Authors: Adane F Wogu, Christopher A Loffredo, Ionut Bebu, George Luta
• Journal: BMC research notes (BMC Res Notes) Vol. 7 Pg. 926 (Dec 17 2014) ISSN: 1756-0500 [Electronic] England
• PMID: 25515761 (Publication Type: Journal Article)

Topics

• Adult
• Birth Weight
• Case-Control Studies
• District of Columbia (epidemiology)
• Educational Status
• Female
• Gestational Age
• Heart Defects, Congenital (epidemiology)
• Humans
• Infant
• Infant, Newborn
• Male
• Maryland (epidemiology)
• Maternal Age
• Mothers
• Risk Assessment (methods, statistics & numerical data)
• Risk Factors
• Smoking
• Virginia (epidemiology)