# The influence of paternal preconception health on infant birth weight: A scoping review

## TL;DR

This review explores how a father's health before conception may affect a baby's birth weight, highlighting areas needing more research.

## Contribution

The study is the first scoping review to systematically examine the relationship between paternal preconception health and infant birth weight.

## Key findings

- Paternal factors like BMI, drug use, and environmental exposures may influence infant birth weight.
- Evidence is mixed for the impact of paternal nutrition, sleep, and mental health on birth weight.
- Most studies were from China and the US, suggesting a need for more global research.

## Abstract

Birth weight is an important determinant of infant growth and development associated with neonatal morbidity (e.g., respiratory distress, hypoglycemia) and mortality, as well as long-term health risks such as developmental delays and chronic conditions (e.g., asthma, type 2 diabetes) in later life. These adverse health outcomes are particularly concerning when infants are born small or large for their gestational age. A potential strategy to improve optimal birth weight is preconception care, with consistent evidence demonstrating a relationship between maternal preconception health and infant birth weight. However, little attention has been given to the influence of paternal preconception health on pregnancy outcomes. This scoping review aimed to capture the existing literature and highlight evidence gaps regarding associations between paternal preconception health and infant birth weight. We followed the Joanna Briggs Institute methodology and the Preferred Reporting Items for Systematic Reviews and Meta-Analysis extension for Scoping Reviews. The review considered studies that included men in the preconception period who identified as the parent of a child for whom infant birth weight outcomes were reported. Medline, PsycINFO, Embase, Scopus and CINAHL databases were searched to June 30, 2024. Two independent reviewers screened the titles/abstracts and full-text articles. Data extraction was performed independently by two researchers using a standardized form in Covidence. The data were synthesized narratively according to the paternal preconception health factors identified within the included studies (e.g., physical well-being, health behaviors, substance use, environmental exposures, mental health, and treatment effects). From 7,690 citations, 57 published studies were included in the review. Most studies were conducted in China (n = 18, 31.6%) or the United States (US) (n = 17, 29.8%) and used a cohort design (n = 54, 94.7%). Our review identified growing evidence that specific paternal preconception factors, such as physical well-being (e.g., BMI, physical health), certain medications (e.g., recreational drugs, sulfonylureas, diazepam), and environmental chemical exposure, may adversely influence infant birth weight. There are mixed findings related to other paternal health factors, including some health behaviors (e.g., nutrition, sleep, physical activity), substance use, and mental health. Consideration should be given to expanding preconception counseling and public health initiatives to include fathers, to improve paternal health and potentially reduce risks to offspring (e.g., birth weight). We also identified key areas where further research is required to advance knowledge in this field.