Background Exposure to perfluorinated chemicals (PFCs) is ubiquitous in most regions of the world. The most commonly studied PFCs are perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA). Animal studies indicate that maternal PFC exposure is associated with reduced fetal growth. However, results from human studies are inconsistent.

Objectives To summarise the evidence of an association between exposure to PFCs, particularly PFOS and PFOA, and human fetal growth.

Methods Systematic literature searches were performed in MEDLINE and EMBASE. We included original studies on pregnant women with measurements of PFOA or PFOS in blood during pregnancy or the umbilical cord and risk estimates of birth weight or related outcome according to PFC level. Citations and references from included articles were investigated to locate more relevant articles. Study characteristics and results were added to forms. Completeness of reporting as well as the risk of bias and confounding were assessed. Reporting was done in accordance with PRISMA.

Results Ten studies were eligible. In utero PFOA exposure was associated with decreased birth weight in all studies, even though the magnitude of associations differed and many results were statistically insignificant. PFOS exposure and birth weight were associated in some studies, while others found no association.

Conclusions The literature suggests no consistent association between in utero exposure to PFOS and birth weight. However, exposure to PFOA is associated with decreased average birth weight in populations with high exposure levels. Considering the global exposure to PFCs, this calls for careful interpretation within a public health perspective.