In this cross-sectional study, we evaluated data from the 2014 Bangladesh Demographic and Health Survey (BDHS), which consisted of 7,707 married women aged 15-49 years who lived with at least one child younger than 5 years. This study's primary aim was to examine the relationship between maternal high-risk fertility behavior and child morbidity. To define high-risk fertility behaviors, we considered three variables: maternal age at the time of delivery, birth order, and birth interval. The main outcome measures were mortality-related disease in the past 2 weeks (acute respiratory infection [ARI], diarrhea, and fever) and low birth weight (LBW). We used modified Poisson regression with generalized estimating equations to assess the relationships between the variables of interest. Results indicate that a substantial portion of women (34%) exhibited high-risk fertility patterns; 28.7% engaged in a single high-risk behavior and 5.4% engaged in multiple high-risk behaviors. After adjusting for relevant covariates, high-risk fertility behaviors were significantly associated with an increased likelihood of ARI (adjusted relative risk [