Maternal Exposure to Pyrethroid Insecticides during Pregnancy and Infant Development at 18 Months of Age

Abstract

The possible association between maternal exposure to pyrethroid insecticides (PYRs) during pregnancy and infant development was explored. Levels of exposure to PYRs was assessed by metabolite (3-phenoybenzoic acid, 3-PBA) concentration in maternal spot urine sampled in the first trimester of index pregnancy, and infant development was assessed at 18 months of age using the Kinder Infants Development Scale (KIDS), which is based on a questionnaire to the caretaker. The relationship between KIDS score and maternal urinary 3-PBA levels was examined by a stepwise multiple regression analysis using biological attributes of the mother and infant, breast feeding, and nursing environment as covariates. The analysis extracted 3-PBA and the nursing environment as significant to explain the KIDS score at 18 months of age with positive partial regression coefficients. Inclusion of fish consumption frequency of the mother during pregnancy as an independent variable resulted in the selection of fish consumption as significant, while the two variables were marginally insignificant but still with a positive coefficient with the KIDS score. The result suggested a positive effect of maternal PYR exposure on infant development, the reason for which is not clear, but an unknown confounding factor is suspected.

Pyrethroid Pesticide Exposure and Risk of Primary Ovarian Insufficiency in Chinese Women

“…Since the usage of pyrethroids have increased rapidly in recent years due to the need to replace organophosphate insecticides following use restrictions around the globe, a number of studies have assessed the urinary concentrations of pyrethroid metabolites in the general population, especially for nonoccupationally exposed women. As shown in Table , the GM value of 3-PBA detected in the present control samples (0.251 μg/L) was comparable to the levels measured in pregnant women in France (GM = 0.36 μg/L, n = 1077) and Ghana (GM = 0.23 μg/L, n = 51), as well as general female population in United States (GM = 0.315 μg/L, n = 1346) and Canada (GM = 0.24 μg/L, n = 648). ,,, The arithmetic mean (AM) level of 3-PBA of the healthy women in this study (0.657 μg/L) was also very close to that of Japanese pregnant women (AM = 0.624 μg/L, n = 102) . However, a previous study of pregnant Chinese women ( n = 1149) living in Jiangsu Province reported that the GM concentration of 3-PBA was 0.97 μg/L, which was significantly higher than that of our control population .…”

“…The extensive usage of pyrethroids leads to ubiquitous and continuous human exposure via dietary ingestion and inhalation as well as dermal absorption from the indoor residential environment . The metabolites of pyrethroids have been detected in more than 70% urine samples of nonoccupational adults in many countries, including China. − In particular, recent studies reported that the metabolites of pyrethroids were found in more than 75.5–98.8% of the urine samples of women. − …”

Maternal Health and Nutrition Status, Human Milk Composition, and Growth and Development of Infants and Children: A Prospective Japanese Human Milk Study Protocol

“…Each subscale has options for 'pass' or a 'fail'. Based on the answer sheet, the developmental quotient will be calculated as the sum of the scores on the nine subscales divided by the chronological age of the infant or child [22].…”

Human Risk Associated with Long-Term Exposure to Pyrethroid Insecticides

“…This may be due to differences in the study designs, for example, in the exposure period (i.e., trimester of pregnancy) and the control of potential confounding variables (e.g., current child exposure to pyrethroids and other environmental agents such as neurodevelopmental toxic pesticides), as well as in the timing (3 months to 7 years of age), endpoints, and techniques/practices of child assessment. In addition, there was substantial variability in the urinary levels of the pyrethroid metabolites across studies (e.g., median 3-PBA level of 0.39 μg/L in [57] vs less than the limit of detection of 0.008 μg/L in [58]). On the other hand, the few studies available showed no consistent relationship between neurodevelopment and pyrethroid exposure during childhood, as assessed by metabolite measurements in the child urine.…”