Effect of environmental phthalate exposure on pregnancy duration and birth outcomes

Objectives The objective of this study was to evaluate the impact of phthalate exposure on pregnancy duration and birth outcomes based on the Polish Mother and Child Cohort (REPRO_PL). Material and Methods Phthalate exposure was determined by measuring 11 phthalate metabolites (mono-ethyl phthalate (MEP), mono-iso-butyl phthalate (MiBP), mono-n-butyl phthalate (MnBP), 3OH-mono-n-butyl phthalate (OH-MnBP), mono-benzyl phthalate (MBzP), mono‑ (2-ethylhexyl) phthalate (MEHP), mono-(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), mono-(2-ethyl-5-oxohexyl) phthalate (MEOHP), mono-hydroxy-iso-nonyl phthalate (MHiNP), mono-oxo-iso-nonyl phthalate (MOiNP), and mono-n-octyl phthalate (MOP)) in the urine collected from 165 mothers during the third trimester of pregnancy by high performance liquid chromatography with tandem mass spectrometry (HPLC-MS/MS). The following measures at birth were considered: gestational age, birth weight, length as well as head and chest circumference. Results Pregnancy duration was inversely associated with natural log concentrations (μg/g creatinine) of MEP (standardized regression coefficient (β) = –0.2, p = 0.04) after adjustment for a variety of confounders. Significant impact of MOiNP on head circumference (β = –0.1, p = 0.05) was also observed. Conclusions The study findings add further support to the hypothesis that phthalate exposure may be associated with shorter pregnancy duration and a decreased head circumference, and underscore importance of public health interventions to reduce that exposure.