Association between persistent organic pollutants in human milk and the infant growth and development throughout the first year postpartum in a cohort from Rio de Janeiro, Brazil

Persistent organic pollutants (POPs) are compounds that are recalcitrant and ubiquitous that bioaccumulate in human milk (HM) and can impact infant growth and development. We explore the association between POP concentration in HM at 2-50 days postpartum and infant growth and development trajectory throughout the first year of life. A cohort of 68 healthy adult Brazilian women and their infants were followed from 28 to 35 gestational weeks to 12 months postpartum. HM samples were collected between 2 and 50 days postpartum, and POP concentrations were analyzed using gas chromatography with mass spectrometry. Concentrations of POPs >limit of quantification (LOQ) were defined as presence, and concentrations ≤LOQ as an absence. Growth z-scores were analyzed according to WHO growth charts and infant development scores according to Age & Stages Questionnaires at 1 (n = 66), 6 (n = 50), and 12 months (n = 45). Linear mixed effects (LME) models were used to investigate the association of POPs in HM with infant growth and development. Benjamini-Hochberg (BH) correction for multiple testing was performed to reduce the false discovery ratio. P < 0.1 was considered for models with the interaction between POPs and time/sex. After BH correction, adjusted LME models with time interaction showed (1) a positive association between the presence of β hexachlorocyclohexane and an increase in head circumference-for-age z-score (β = 0.003, P = 0.095); (2) negative associations between total POPs (β = -0.000002, P = 0.10), total organochlorine pesticides (β = -0.000002, P = 0.10), and dichlorodiphenyldichloroethylene concentrations in HM (β = -0.000002, P = 0.10) and fine motor scores. No statistical difference between the sexes was observed. Postnatal exposure to organochlorine pesticides in HM shows a positive association with the trajectory of head circumference-for-age z-score and a negative association with the trajectories of fine motor skills scores. Future studies on POP variation in HM at different postpartum times and their effect on infant growth and development should be encouraged.

Association of pre-pregnancy maternal overweight/obesity and dietary intake during pregnancy with the concentrations of persistent organic pollutants in the human milk of women from Rio de Janeiro, Brazil

Persistent organic pollutants (POPs) are toxic chemical compounds that can bioaccumulate, adhere to lipid matrices, and affect human health. This study aimed to investigate the association between maternal pre-pregnancy overweight/obesity and dietary intake during pregnancy and POP concentrations in the human milk of women from Rio de Janeiro, Brazil. One hundred and forty-seven women were followed from the third trimester of pregnancy until 119 days postpartum, and 77 human milk samples were analyzed between 2 and 119 days postpartum. POP concentrations were analyzed using gas chromatography-triple quadrupole mass spectrometry. Pregnancy dietary intake was estimated using a semi-quantitative food frequency questionnaire, and pre-pregnancy body mass index at baseline was classified as normal or overweight/obesity. Multiple logistic and linear regression models were performed to investigate the association between pre-pregnancy overweight/obesity, dietary intake during pregnancy, and POP concentrations in human milk. The models were adjusted for maternal age, maternal schooling, total cholesterol serum concentrations, and time postpartum. The analyses were corrected for multiple comparisons using the Benjamini-Hochberg test. Significant associations were observed between pre-pregnancy overweight/obesity and dichlorodiphenyldichloroethane (ppDDE), polychlorinated biphenyl (PCB)74, PCB138, PCB153, PCB170, PCB180, total PCBs, total 4PCBs, total 2 organochlorine pesticides (OCPs), and total POP concentrations. Higher daily lipid intake during pregnancy increased human milk hexachlorobenzene (HCB). This study showed that pre-pregnancy overweight/obesity and total lipid intake during pregnancy were associated with POP concentrations in the milk of women from Rio de Janeiro, Brazil. To promote adequate nutritional status since preconception and surveillance and control of POP in the environment could be essential to ensure binomial mother-infant health and biomonitoring studies and programs for these POPs should be stimulated.

Prepregnancy Body Mass Index and Lipoprotein Fractions are Associated with Changes in Women's Serum Metabolome from Late Pregnancy to the First Months of Postpartum

BACKGROUND

Pregnancy and postpartum are periods of intense changes in women's metabolism. The knowledge of the metabolites and maternal factors underlying these changes is limited.

OBJECTIVES

We aimed to investigate the maternal factors that could influence serum metabolome changes from late pregnancy to the first months of postpartum.

METHODS

Sixty-eight healthy women from a Brazilian prospective cohort were included. Maternal blood and general characteristics were collected during pregnancy (28-35 wk) and postpartum (27-45 d). A targeted metabolomics approach was applied to quantify 132 serum metabolites, including amino acids, biogenic amines, acylcarnitines, lysophosphatidylcholines (LPC), diacyl phosphatidylcholines (PC), alkyl:acyl phosphatidylcholines (PC-O), sphingomyelins with (SM) and without hydroxylation [SM(OH)], and hexoses. Metabolome changes from pregnancy to postpartum were measured as log₂ fold change (log₂FC), and simple linear regressions were employed to evaluate associations between maternal variables and metabolite log₂FC. Multiple comparison-adjusted P values of < 0.05 were considered significant.

RESULTS

Of 132 metabolites quantified in serum, 90 changed from pregnancy to postpartum. Most metabolites belonging to PC and PC-O classes decreased, whereas most LPC, acylcarnitines, biogenic amines, and a few amino acids increased in postpartum. Maternal prepregnancy body mass index (ppBMI) showed positive associations with leucine and proline. A clear opposite change pattern was observed for most metabolites across ppBMI categories. Few phosphatidylcholines were decreased in women with normal ppBMI, while an increase was observed in women with obesity. Similarly, women with high postpartum levels of total cholesterol, LDL cholesterol, and non-HDL cholesterol showed increased sphingomyelins, whereas a decrease was observed for women with lower levels of those lipoproteins.

CONCLUSIONS

The results revealed several maternal serum metabolomic changes from pregnancy to postpartum, and the maternal ppBMI and plasma lipoproteins were associated with these changes. We highlight the importance of the nutritional care of women prepregnancy to improve their metabolic risk profile.