Margarita Levario-Carrillo

Relation between Maternal Body Composition and Birth Weight

In order to establish the relationship between maternal body composition indicators (fat-free mass, fat mass, total body water) and birth weight, a cross-sectional study was designed, based on 196 pairs of mothers and live singleton newborns with gestational age of 37 weeks or more. Immediately after delivery, the mothers were interviewed to obtain information about different birth weight predictors. An analysis of maternal body composition through bioelectric impedance was held. Multiple linear regression was used to measure the effect of each variable on birth weight. The birth weight mean was 3,251 ± 514 g. Maternal height was 160.44 ± 6.3 cm, total net weight gain was 5.85 ± 5.15 kg, fat mass consisted of 15.84 ± 6.72 kg, and fat-free mass was 50.42 ± 7.65 kg; total body water was 34.82 ± 5.61 liters. The model which included total body water and all predictors found to be associated with birth weight in the bivariate analysis (maternal age, gestational age, gender, placenta weight, and placenta weight squared) was found to be the best in explaining the variability of birth weight (R2 = 45.26%). Fat mass was an important predictor only in the subgroup of women within the low tertile of body mass index. In conclusion, fat-free mass and total body water explained a major proportion of the variability of birth weight in comparison with the mother’s weight gain during the pregnancy period, which has already been considered an important predictor of birth weight.

Placental morphology of rats prenatally exposed to methyl parathion

Although prenatal exposure to pesticides has been associated with numerous adverse reproductive effects, data on the effects of such toxics in the placenta is limited. Thus, the present study was carried out to determine the morphology of the rat placenta exposed to the organophosphate pesticide methyl parathion (MP) in ad libitum fed and restricted diet animals. The pregnant females were randomly divided into control groups and experimental groups, the latter of which received MP at the doses of 0.0, 1.0, 1.5 and 2.0 mg/kg. Most cells in the maternal-fetal interface showed significant alterations in the presence of MP. Trophoblast giant cells exhibited either prominent characteristics of degeneration or normal morphology with many phagosome vacuoles, apparently containing cell debris. Vascular congestion was also more frequent in the labyrinth of the treated animals. Areas of fibrosis and hemorrhage were found in the decidua, as well as decidual cells presenting pyknotic nuclei and acidophilic cytoplasm. In the placentas of females treated with both restricted diet and MP, such changes were much more severe. Together, these alterations suggest a direct, toxic effect of MP on the placental cells. The phagocytic activity exhibited by trophoblast cells, may be playing a role in the removal of death cells from the maternal-placental interface and/or in a compensatory mechanism to maintain the uptake of maternal nutrients, following decreased metabolic exchange functions of the labyrinth due to the toxic effect of the MP.

Body composition of patients with hypertensive complications during pregnancy.

Objective: To determine the body composition of women with the diagnoses of gestational hypertension or preeclampsia. Methods: Cross-sectional study, including four groups of patients who were in the third trimester: those with an uncomplicated pregnancy (n = 110), those with a diagnosis of gestational hypertension (n = 38), those with mild preeclampsia (n = 8), and those with severe preeclampsia (n = 11). Their fat mass, fat-free mass, and total body water were estimated by bioelectric impedance. Results: The fat mass was 20 ± 7 kg in the control group and 26 ± 13 kg in the group with gestational hypertension (p < 0.05). The total body water was 36 ± 6 L in the control group, 50 ± 10 L in the patients with gestational hypertension, 52 ± 10 L in those with mild preeclampsia, and 48 ± 9 L in those with severe preeclampsia (p < 0.05). Conclusion: The results suggest that maternal body composition shows significant differences in patients with hypertensive complications during pregnancy. These data may be related to a possible inadequate distribution of the volume of water as a result of alterations in capillary permeability.

Deficiencia de folatos y su asociación con defectos de cierre del tubo neural en el norte de México

Objective. To evaluate folic acid deficiency and other risk factors and their relationship with the occurrence of neural tube defects (NTD), in the rural population of northern Mexico (Chihuahua, Durango and Zacatecas). Material and methods. A multicentric case-control study was performed. Cases were both live and stillborn with NTD, and controls were healthy newborns without congenital malformations. Exposure to known risk factors was determined, establishing its association with NTD using multiple logistic regression analysis. Results. Risk factors associated to NTD were: folic acid deficiency (OR 11.1; CI 95% 1.2-106.2, p= 0.04); the antecedents of previous NTD pregnancies (OR 3.3; CI 95% 1.1-18.8, p= 0.05) and stillbirths (OR 7.1; CI 95% 1.1-46.3, p= 0.04). Conclusions. Folic acid deficiency is one of the major risk factors associated to NTD among the rural population of northern Mexico. Further investigations are necessary to determine the role of involved risk factors and implement adequate preventive measures.

Effects of exposure to pesticides during pregnancy on placental maturity and weight of newborns: A cross-sectional pilot study in women from the Chihuahua State, Mexico

It is known that pesticides cross the placental barrier and can cause alterations in the development of placental structures resulting in adverse effects in reproduction. The objectives of this study were to investigate the effects of pesticide exposure during pregnancy on placental maturity and to evaluate the relationship between placental maturity, gestational age and birth weight. We collected the placentas from singleton pregnancies from women exposed (n = 9) and non-exposed (n = 45 full-term and n = 31 preterm) to pesticides as evaluated geographically, by questionnaire and by acetylcholinesterase levels. Placental morphometry from the central and peripheral regions was examined by microscopy and staining with hematoxylin and eosin. The placental maturity index (PMI) was estimated by dividing the number of epithelial plates in terminal villi to their thickness in 1 mm2 of the placental parenchyma. Gestational age, birth weight and the following characteristics of the mother were also recorded: pre-pregnancy body mass index, weight gain during pregnancy and hemoglobin concentrations. Birth weight and the gestational age were correlated with PMI (r = .54 and r = .44, respectively; p < .01). Pesticide exposure was associated with a higher PMI (beta = 7.38, p = .01) after adjusting by variables related to placental maturity. In conclusion, the results suggest a relationship between prenatal exposure to pesticides and placental maturity and may potentially affect the nutrient transport from the mother to the fetus.

Parathion, a Cholinesterase-Inhibiting Plaguicide Induces Changes in Tertiary Villi of Placenta of Women Exposed: A Scanning Electron Microscopy Study

The objective of this work was to describe the anatomy of placentas from women who were at risk of exposure to parathion during their pregnancy, when examined with the light and scanning electron microscopes. Twenty term placentas were analyzed; 10 from women living in an agricultural area, who were at risk of exposure to parathion during their pregnancy, and 10 from women living in an urban area, not expressly exposed to pesticides. Each sample was examined with both light and scanning electron microscopes. Cholinesterase activity was significantly reduced in blood from women of the exposed group. In some placentas of women exposed to parathion, recent microinfarctions, microcalcifications and increased deposition of fibrinoid material were seen, along with a larger proportion of atypical characteristics of villi, such as bullous and balloon-like formations with nonhomogeneous surface, and other areas devoid of microvilli. These observations suggest that in chronic exposure to pesticides, the rate of atypical characteristics of placental villi increases, which could be related to changes in the fetus biology. In this study, one newborn from the exposed group showed intrauterine growth retardation and another one, some signs of hypoxia.

Creencias y conocimientos de un grupo de médicos sobre el manejo de la alimentación del niño con diarrea aguda

Objective. To identify the beliefs and knowledge of a group of rural physicians on the dietary management of children under five years of age, with acute diarrhea. Physicians’ dietary management was compared with that recommended by the World Health Organization. Material and Methods. A cognitive anthropology study was carried out from July to December 1998, on ten physicians that care for the infant population ascribed to Hospital Rural IMSS-Solidaridad of San Juanito Bocoyna, Chihuahua, Mexico. Data were collected through focus groups, case vignettes, free listing, pile sorting, and a semi-structured questionnaire, and then crossreferred. Results. The physicians recognized the negative impact of diarrhea on the nutritional state of the child, but not all of them evaluated this state. Prevailing interventions were antibiotic therapy, fluid management, and feeding recommendations. Among the latter, the most consistent were breastfeeding, delayed feeding, and gradual feeding. Conclusions. The obtained information is in conflict with WHO’s recommendations, specially with that of sustained feeding. The English version of this paper is available at: http:// www.insp.mx/salud/index.html

Body Composition of Women with Newborns Who Are Small for Gestational Age

Background: The relationship between maternal and placental hemodynamic disorders and fetal growth is well known, but few studies have evaluated a link between maternal extracellular water (EW) and newborn birth weight. Objective: To identify the characteristics of body composition (BC) of women with small for gestational age (SGA) newborns, and to determine the relationship between maternal EW and birth weight of the baby. Methods: We studied maternal BC using multifrequency bioelectric impedance in the second and third trimesters of pregnancy. Newborns with weight below the 10th percentile were classified as SGA; those with weights between the 10th and 90th percentiles as appropriate for gestational age (AGA), and large for gestational age (LGA) were those with weights above the 90th percentile. Results: We studied 460 women and their BC varied depending on whether their newborns were SGA, AGA or LGA. EW was lower in the mothers of SGA (11 ± 2 l) compared to AGA (12 ± 3 l) newborns (p < 0.01). We identified a significant relationship (p < 0.01) between maternal EW in the second trimester and the weight of the newborn, β = 43 (95% CI 27–58). Conclusion: BC of women whose newborns are SGA differs significantly from that of women whose newborns are AGA, a result which suggests that the mothers of SGA infants may have a disordered hemodynamic state during the second trimester of pregnancy.

In vitro assessment of the genotoxicity of ethyl paraoxon in newborns and adults

This in vitro experiment measured the genotoxic effects of ethyl paraoxon, the active metabolite of ethyl parathion. To assess genotoxicity, we used the micronuclei (MN) technique by blocking cytokinesis, and the ‘comet’ assay. We cultured peripheral blood samples from healthy adults and umbilical cord blood samples from four clinically healthy newborns to identify the frequency of MN. After 48 hours, we added the following ethyl paraoxon concentrations to the cultures: 0.0, 0.075, 0.100, 0.160, and 0.200 μg/mL. For the comet assay, following Singhs technique, we treated the blood samples for 2 hours with similar doses of the metabolite. The comet assay results, at a concentration of 0.075 μg/mL, showed that ethyl paraoxon causes a greater DNA migration that followed a dose-response pattern, a greater intensity being observed in lymphocytes from newborns. A comparison of the treatment and control groups indicated that only the 0.200 μg/mL concentration produced a slight increase in MN. In conclusion, our study identified primary DNA damage due to ethyl paraoxon, with a major effect on newborn lymphocytes, as well as an effect on the frequency of MN in the study groups at high concentrations only.

Relación entre las reservas de hierro maternas y del recién nacido

Objetivo. Determinar la relacion de los valores hematologicos maternos y neonatales en casos de reservas maternas de hierro bajas, moderadas y normales. Material y metodos. Diseno transversal en el que se incluyo a 163 mujeres embarazadas y sus neonatos de termino, derechohabientes del Hospital de Ginecologia y Obstetricia numero 15 del Instituto Mexicano del Seguro Social (IMSS) en Chihuahua, Chih., Mexico. Se analizaron antecedentes maternos. Se determinaron niveles de hemoglobina, hematocrito y ferritina serica en muestras maternas y de cordon umbilical. Se definieron reservas de hierro maternas de acuerdo a ferritina (µg /l): bajas o = 20.1. Se utilizo la prueba de Kruskal Wallis para establecer diferencias entre grupos, ji cuadrada para diferencia de proporciones y r de Pearson para establecer la relacion entre reservas de hierro maternas y del recien nacido. Resultados. Se determino una debil correlacion entre la ferritina materna y neonatal r=0.14 (p=0.07). Las medias geometricas de ferritina neonatal respecto a las reservas maternas bajas, moderadas y normales fue de 4.77, 4.85 y 5.02, respectivamente (p=0.12). Las reservas de hierro maternas se modificaron con el suplemento de hierro (p=0.01). Conclusiones. Las reservas de hierro en el recien nacido estan en estrecha relacion con las maternas. Las mujeres que toman suplementos con hierro durante la gestacion tienen reservas mayores al final del embarazo. El texto completo en ingles de este articulo esta disponible en: http://www.insp.mx/salud/index.html