[Levels of phthalate internal exposure levels in pregnant women and influencing factors].

OBJECTIVE

To investigate the levels and influencing factors of phthalate internal exposure in pregnant women (gestation age ≤ 16 weeks).

METHODS

During April to June in 2013, 1 020 pregnant women (gestation age ≤ 16 weeks) who had established the maternal care manual were recruited in maternal and child health hospital of Siming District, Xiamen city. Participators were asked to complete a questionnaire to obtain information on socio-demographic characteristics, lifestyle behaviors, and antenatal examination and to provide a urine sample. Finally, 998 pregnant women who provided a urine sample and completed the questionnaire were enrolled. Adopting systematic sampling method, 100 ones were selected randomly among 998 pregnant women. High performance liquid chromatography-electrospray ionization-tandern mass was used to determine the concentration of five phthalate monoesters in each urine, including mono-n-methyl phthalate (MMP), mono-ethyl phthalate (MEP), mono-butyl phthalate (MBP), mono-benzyl phthalate (MBzP), mono-ethylhexyl phthalate (MEHP). Based on the measurements and questionnaire data, multivariate logistic regression was used to analyze the association between the phthalate monoester levels and potential influential factors.

RESULTS

The detection rates of MMP, MEP, MBP, MBzP and MEHP in 100 pregnant urine samples were 94%, 93%, 87%, 83%, 99%, respectively. And the urinary median uncorrected concentrations of MMP, MEP, MBP, MBzP and MEHP in 100 urine samples were 20.56, 17.62, 10.15, 2.03, and 5.12 ng/ml, respectively. Specific gravity-corrected concentration were 20.81, 20.36, 12.88, 2.58, 5.00 ng/ml, respectively. The results of multivariate logistic regression analysis indicated that: education degree was negatively associated with urinary concentration of MMP, MEP, MBP, MBzP and MEHP, OR (95% CI) were 0.495 (0.253-0.966), 0.380 (0.191-0.755), 0.379 (0.186-0.774), 0.401 (0.196-0.819), 0.373(0.183-0.762), respectively. Participants who had hair permed and dyed during pregnancy had higher urinary level of MBP and MBzP, OR (95% CI) were 12.867 (1.240-133.525), 15.982 (1.367-186.911), respectively; Participants who use cosmetics during pregnancy had higher urinary level of MEP and MBP, OR (95% CI) were 2.977 (1.012-8.757), 4.440 (1.485-13.272), respectively; plastic bottled water consumption was positively associated with urinary concentrations of MEP and MEHP, OR (95% CI) were 3.780 (1.417-10.083), 2.699 (1.039-7.010), respectively; annual household income was negatively associated with urinary concentration of MMP, OR (95% CI) was 0.597 (0.372-0.959); individuals who took medications during pregnancy had higher urinary level of MEHP than non-takers, OR (95% CI) was 4.853 (1.084-21.732).

CONCLUSION

Pregnant women whose gestation age was less than 16 weeks are generally exposed to phthalate. Phthalate internal exposure levels are significantly associated with most measured factors and the influencing factors with different phthalates internal exposure levels are different.