Prenatal exposure to heavy metal mixtures and anthropometric birth outcomes: a cross-sectional study.

BACKGROUND: Numerous studies have suggested significant associations between prenatal exposure to heavy metals and newborn anthropometric measures. However, little is known about the effect of various heavy metal mixtures at relatively low concentrations. Hence, this study aimed to investigate associations between prenatal exposures to a wide range of individual heavy metals and heavy metal mixtures with anthropometric measures of newborns. METHODS: We recruited 975 mother-term infant pairs from two major hospitals in Israel. Associations between eight heavy metals (arsenic, cadmium, chromium, mercury, nickel, lead, selenium, and thallium) detected in maternal urine samples on the day of delivery with weight, length, and head circumference at birth were estimated using linear and Bayesian kernel machine regression (BKMR) models. RESULTS: Most heavy metals examined in our study were observed in lower concentrations than in other studies, except for selenium. In the linear as well as the BKMR models, birth weight and length were negatively associated with levels of chromium. Birth weight was found to be negatively associated with thallium and positively associated with nickel. CONCLUSION: By using a large sample size and advanced statistical models, we could examine the association between prenatal exposure to metals in relatively low concentrations and anthropometric measures of newborns. Chromium was suggested to be the most influential metal in the mixture, and its associations with birth weight and length were found negative. Head circumference was neither associated with any of the metals, yet the levels of metals detected in our sample were relatively low. The suggested associations should be further investigated and could shed light on complex biochemical processes involved in intrauterine fetal development.

Pregnancy after bariatric surgery: Effects of personalized nutrition counseling on pregnancy outcomes.

BACKGROUND & AIMS: Nutritional challenges following bariatric surgery can be intensified during pregnancy and may have crucial effects on the fetus, including lower birth weight. To the best of our knowledge, the effect of nutritional counseling during post-bariatric pregnancy to improve maternal diet quality and eating habits on neonatal outcome has not been evaluated. The aim of this research was to examine the effects of personal nutritional counseling during post-bariatric pregnancy on nutritional intake and neonatal outcomes. METHODS: We performed a non-randomized, intervention-control clinical trial. Women (n = 61) were divided into three groups; two prospective, and one retrospective: 1. An Intervention Bariatric Prospective group 2. A Control Prospective group without surgery, and 3. A Control Bariatric Retrospective group. Patient enrollment was performed from April 2016 to March 2018. The intervention program included biweekly visits with a pregnancy nutrition certified bariatric dietitian. Data collection was performed four times during pregnancy, and included demographic and eating habits questionnaires, 24 h dietary recall, and information about delivery outcomes. In the retrospective group delivery outcomes and Food Frequency Questionnaire was collected once, after delivery. RESULTS: There were no differences between groups at baseline except for a higher pre-pregnancy BMI in the post-bariatric groups. In the prospective groups, dietary protein, energy, and iron were found to be consumed in higher amounts in the Control-Prospective group than in the Intervention Bariatric-Prospective group (p < 0.05), without the addition of supplements. On the other hand, iron and calcium calculated from diet with supplements, were found to be significantly higher in the Intervention Bariatric Prospective group than in the Control Prospective group. In addition, consumption of saturated fats, oil, and salty snacks was lower in both prospective groups compared to the retrospective group (p < 0.05), suggesting better food quality habits for the bariatric group with nutritional counseling. Mean birth weight was significantly lower in the Control Bariatric Retrospective group than in the Control-Prospective group (3074 ± 368 g vs. 3396 ± 502 g, respectively. p = 0.023). In the Intervention Bariatric Prospective group, mean birth weight was 3168 ± 412 g, and no significant difference was observed from the Control Prospective group. Birth percentiles were also significantly lower in the Control Bariatric Retrospective group compared to the Control Prospective group (27th vs. 42nd, respectively. p < 0.05). In the Intervention Bariatric Prospective group, mean birth percentile was 35th, and no significant difference was observed from the Control Prospective group. As for the weight change of the woman during pregnancy, the highest variability was noted among the Control Bariatric Retrospective group with cases of weight loss up to 37 kg, due to conception close to the bariatric operation. Nevertheless, this variable was controlled, and showed no significant impact on birth weight results. CONCLUSIONS: Our results suggest that personalized nutritional counseling care during post bariatric pregnancy improved nutrient intake of mothers and may contribute to higher birth weight of offspring. Further research is needed to examine the effects of prenatal nutrition care intervention, in addition to repeating this trial with a larger sample size, to allow for clearer findings. CLINICAL TRIAL REGISTRATION: IRB number: 0310-15-RMB. IDENTIFICATION NIH NUMBER: NCT02697981 URL: https://www.nih.gov.