Morfología de la placenta en recién nacidos con defecto congénito / Morphology of the placenta in newborns with congenital defects

El objetivo del estudio fue comparar el índice de madurez placentaria y las alteraciones histopatológicas en placentas de recién nacidos/óbitos con y sin defecto congénito (DC). Se realizó un estudio tipo casos y controles. Se incluyeron n=25 casos yn=50 controles sin DC. Los casos se clasificaron de acuerdo a la presencia de DC aislado (n=17) omúltiple (n=8). Se incluyeron recién nacidos/óbitos (RN) con una edad gestacional (EG) > 20 semanas. Se excluyeron embarazos gemelares. Se recolectó información sobre las características clínicas del producto y de la madre, antropometría del RN y su evaluación de APGAR. Se examinó la placenta, macroscópica y microscópicamente, para determinar la presencia y extensión de alteraciones histopatológicas. Se determinó el índice de madurez placentaria (IMP), calculado dividiendo el número de membranas vásculo sinciciales en 1 mm2 entre el grosor de las mismas (µ). El IMP (media ±DE) fue de 27.77±14 en el grupo de controles, 30.31±12 en el grupo de casos aislados y 16.76± 1 en el grupo de DC múltiple (p<0.05).El resto de las variables evaluadas no mostraron diferencias significativas entre grupos. En conclusión este trabajo muestra una menor madurez placentaria asociada con la presencia de DC múltiple.

The objective of the study was to compare the placental maturity index (PMI) and pathohistological alterations of placentas from newborn/stillborns (NB) with or without congenital defects (CD). A case control study was carried out. N=25 CD cases and n=50 controls without CD were included. Cases were classified according to the presence of simple (n=17) or multiple (n=8) CD. Newborn/stillborns with gestational age >20 weeks were included. Twin pregnancies were excluded. We collected information on clinical characteristics of the NB and the mother, NB anthropometry and APGAR score. The placenta was macro and microscopically examined to determine the presence and extension of histological alterations. The PMI was obtained by dividing the number of vasculo-syncytial membranes in 1 mm2, by their thickness (µ). The PMI (Mean ± SD) was 27.77 ± 14 in the control group, 30.31 ± 12 in the group diagnosed with simple CD, and 16.76 ± 1 in the group diagnosed with multiple CD (p<0.05. The rest of the assessed variables did not show significant difference between groups. In conclusion, this work shows a lower placental maturity associated with the presence of multiple CD.

Defectos del tubo neural y de labio y paladar hendido: un estudio morfológico / Neural tube defects, cleft lip and palate: a morphological study

El objetivo del trabajo fue realizar una evaluación morfológica externa de recién nacidos (RN) y lactantes con diagnóstico de defectos de tubo neural (DTN) y labio hendido c/s paladar hendido (LH c/s PH) para determinar el tipo de defecto, ubicación, extensión, clasificación y evaluar la proporción de RN con retardo del crecimiento intauterino (RCIU) y lactantes desnutridos. Estudio descriptivo. Se estudiaron 36 niños desde su nacimiento hasta los 12 meses de edad; 20 con DTN y 16 con LH c/s PH. El estudio se realizó en cinco hospitales de la ciudad de Chihuahua, México. Se hizo una evaluación morfológica externa y antropometría de los niños. Los DTN se clasificaron como lesiones abiertas y cerradas, como defectos altos o bajos, según el modelo de sitios múltiples y por la CIE-10. Los LH c/s PH se clasificaron como unilaterales o bilaterales, completos e incompletos y como aislados o múltiples. Se determinó RCIU en los RN y desnutrición en los lactantes. El análisis estadístico se realizó con el paquete STATA 8.0 para Windows. Se estudiaron 20 casos de DTN; 3 lactantes y 17 RN. De LH c/s PH fueron 8 lactantes y 8 RN. En cuanto a los DTN, 60 por ciento fueron mielomeningocele y correspondían a lesiones abiertas. El 85 por ciento se localizaron a nivel alto. En el modelo de cierres múltiples, el Z1 fue el 80 por ciento. Los LH c/s PH más frecuentes fueron aquellos con hendidura completa (50 por ciento). El 35 por ciento de los RN con DTN tuvieron RCIU y el 67 por ciento de los lactantes presentaron desnutrición. Es importante conocer los mecanismos del desarrollo de las anomalías congénitas ya que esto permite precisar el momento en que ocurrió la falla y permite estudiar los factores predisponentes, con lo cual se puede ofrecer asesoramiento genético para una posible prevención.

The objective of this study was to perform an external morphological evaluation of newborn (NB) and lactating children (LC) with diagnosis of neural tube defects (NTD) and cleft lip c/s palate (CL/s PH) to determine the type of defect, location, extent, classification and assess the proportion of infants with intrauterine growth retardation (IUGR) and malnourished infants. A descriptive study in 36 children from birth to 12 months of age , 20 with NTD and 16 with LH c / s PH was carried out. The study was conducted in five hospitals in the city of Chihuahua, Mexico. An external morphological assessment and anthropometry of children were performed. The DTN lesions were classified as open and closed, as defects high or low, depending on the model of multiple sites and ICD-10. The LH c / s PH were classified as unilateral or bilateral, complete or incomplete, and as isolated or multiple. IUGR was determined in the RN and malnutrition in infants. A statistic analysis was made with STATA 8.0 for Windows. We studied 20 cases of NTDs, 3 LCs and 17 RN. LH c/s PH were 8 LC and 8 RN. The DTN, 60 percent were myelomeningocele and corresponded to open lesions. Eighty five percent were located at high level. In the model of multiple closures, the Z1 was 80 percent. The LH c/s PH were more frequent with complete cleft (50 percent). The 35 percent of newborns with NTD had IUGR and 67 percent of LC had malnutrition. It is important to understand the mechanisms of development of congenital anomalies as this allows to specify the time the fault occurred and to study the underlying diseases to offer genetic counseling for possible prevention.

Altered expressions of MMP-2, MMP-9, and TIMP-2 in placentas from women exposed to lead.

Experimental studies have shown that prenatal exposure to lead (Pb) produces morphological changes related to extracellular matrix remodelling. To analyse whether the matrix metalloproteinases (MMPs), particularly MMP-2, MMP-9, and the tissue inhibitor of metalloproteinases-2 (TIMP-2), are associated with morphological alterations found in placentas, the expression of these enzymes was evaluated by immunohistochemical and image analyses in placentas of women with histories of environmental exposure to Pb. The median maternal concentration of Pb in blood was 4.68 µg/dL (x = 5.85 ± 6.48 µg/dL). Significant differences related to the exposure to Pb were not detected in newborn or placenta weight. MMP-2, MMP-9, and TIMP-2 were expressed in the syncytiotrophoblast layer of placental villi. A significant increase in both MMP-2 and MMP-9 was observed in placentas of women with concentrations of Pb in blood ≥4.68 µg/dL (p = 0.01 and 0.03 for MMP-2 and MMP-9, respectively) and decrease in TIMP-2 expression (p = 0.01) resulted in a significant increase in MMP-2/TIMP-2 ratio (p < 0.01). Increased expression of MMPs may be induced to aid in repairing placental tissue damaged by the exposure to Pb and that TIMP-2 decreases its expression to permit tissue repair. Increased expression of MMPs may be important to consider as a mechanism for generating placental abnormalities and in the induction of preterm delivery or abortion.

Relación entre los niveles de ácido fólico, vitamina B12 y homocisteína materna y los defectos de tubo neural y labio hendido / Relation between levels of folic acid, vitamin B12 and maternal homocysteine with neural tube defects and cleft lip

El objetivo del trabajo fue determinar la asociación entre los niveles de ácido fólico, vitamina B (Vit B12) y homocisteína (Hci) maternos, con defectos del tubo neural (DTN) y labio hendido (LH) con y sin paladar hendido (c/s PH). Se realizó un estudio tipo casos y controles. Casos, con diagnóstico de DTN y LH c/s PH (n=36) y cuatro controles hospitalarios por caso (n=141). Se incluyeron recién nacidos (RN) y lactantes hasta 12 meses de edad. Las variables de pareamiento fueron: edad del RN o lactante, etnia y hospital. Un 23 por ciento de etnia Tarahumara y 77 por ciento mestizos. Se determinó ácido fólico intraeritrocitario (AFI), plasmático (AFP) y Vit B12 por radioinmunoensayo, la Hci por inmunoensayo de fluorescencia polarizada. Se consideró deficiencia si el AFI fue <160 ng/mL, AFP <3.5 ng/ mL y la Vit B12 <200 pg/mL e hiperhomocisteinemia, si Hci >15 J.mol/L. El análisis estadístico se realizó a través de regresión logística condicionada. Se identificó deficiencia de AFI en el 22 por ciento de las mujeres cuyos recién nacidos o lactantes presentaron algún tipo de defecto congénito y en el 12 por ciento de los controles. La relación entre AFI y DTN, LH c/s PH ajustada por edad materna, exposición a plaguicidas y zona de residencia fue RM 2,96 (IC 95 por ciento 0,92-9,46). No se encontraron diferencias en los niveles de Hci ni de Vit B12. Conclusiones: Nuestros resultados sugieren que RN cuyas madres cursan con una deficiencia de AFI tienen mayor riesgo de presentar DTN y LH c/s PH.

Objective: To determine the association between maternal folate deficiency, neural tube defects (NTDs), and cleft lip, with and without cleft palate (CL/P). Material and methods: A case/control study was conducted. The cases included subjects with diagnoses of NTD and CL/P (n=36) and four hospital controls per case (n=141); the study included newborns (NBs) and nursing babies up to 12monthsof age. The parameter variables were the following: the age of the NB or nursing baby, the ethnic group, and the hospital of origin. The Tarahumara ethnic group made up 23 percent of the cases, while 77 percent were mestizos. The red cell folate (RCF), the plasma folie acid (PFA), and the vitamin B12 levels were determined by radioimmunoassay and the homocysteine levels by polarized fluorescence immunoassay. A deficiency was considered to be present if the RCF were <160 ng/mL, the PFA <3.5 ng/mL and the vitamin B <200 pg/ mL; hyperhomocysteinemia was defined as HC >15 J,mol/L. The statistical analysis was carried out through of conditional logistic regression. Results: An RCF deficiency was identified in 22 percent of the women whose newborn or nursing babies presented with some type of congenital defect and in 12 percent of the controls. The correlation adjusted by maternal age, exposure to pesticides and zone of residence was OR 2.96 (CI 95 percent 0.92-9.46). There was no difference in vitamin B12 or homocysteine levels between groups. Conclusions: Our results suggest that newborns whose mothers present with an RCF deficiency have an increased risk of displaying NTD and CL/P.

Decrease of muscarinic cholinergic receptors expression in placenta from rats exposed to methyl parathion.

Placental transfer of methyl parathion (MP), an organophosphate pesticide, could involve effects on cholinergic system. To analyze whether placental cholinergic system is altered by prenatal exposure to MP, expression of muscarinic cholinergic receptors (M1 and M2 subtypes; mAChR) was determined in pregnant rats exposed to MP at 0.0, 1.0, 1.5, and 2.0 mg/kg. An immunohistochemical analysis for M1 and M2 mAChR was performed, and the density of the mAChR signal was measured by image analysis. M1 and M2 mAChR were found in the trophoblast present in the labyrinth, with an 18% predominance of M2 over M1 in the non-exposed group. The expression of M1 and M2 mAChR in placentas exposed to MP showed a decrease when compared with the non-exposed group (P < 0.05); a dose-response effect was not detected. These results demonstrate that prenatal exposure to MP causes changes in the placental expression of mAChR M1 and M2, suggesting that related placental cholinergic functions could be affected.

Placental immaturity and hyperinsulinaemia in full-term newborns.

BACKGROUND: Evidence from large studies suggests that low birthweight is a risk factor for cardiovascular disease and glucose metabolism disorders in adulthood, but the physiological mechanisms involved in intrauterine growth conditioning low birthweight are not completely understood. The objectives of this study were to determine whether placental immaturity (PI), defined as the lower quartile of placental maturity index (PMI), is associated to hyperinsulinaemia at birth and to identify the risk factors associated with PI. MATERIALS AND METHODS: Cross-sectional study conducted at medical research units of two Mexican general hospitals. A total of 272 full-term newborns with gestational age >/= 38 and < 41 weeks were allocated into the corresponding group according to the quartile distribution of PMI. Data from the lower (PMI < 13.3) and higher quartile (PMI >/= 24.3) were compared. The PMI was estimated by dividing the number of epithelial plates by the average thickness of the epithelial plate. Serum measures included cord glucose and insulin levels of the newborns at birth. RESULTS: A total of 74 (27.2%) children had hyperinsulinaemia at birth, of them 47 (63.5%) with PI. The adjusted multiple regression analysis showed a strong association between PI and hyperinsulinaemia at birth [odds ratio (OR) 2.6; CI 95% 1.3-4.3). Additional adjusted analysis showed that both mother's age

Micronucleus frequency in human umbilical cord lymphocytes.

The human fetus is exposed to a variety of environmental agents and drugs which cross the placenta and can induce DNA damage. Micronucleus (MN) determination is a suitable and sensitive method for measuring DNA damage and since umbilical cord blood is obtained without any risk for the newborn, we measured the frequency of MN in cells from cord blood in four groups of healthy newborns (NB): 35 NB whose mothers lived in two urban cities (groups I and II); 16 NB from an agricultural area (group III); and 15 NB of mothers with high-risk pregnancy (group IV). MN were also evaluated in the mothers of NB from group I (n=17) and group III (n=14). Acetylcholinesterase (AChE) concentration was measured in groups I and III. The average frequency of binucleated cells with MN was 3.7+/-1.4 in 1000 cells in mothers and 1+/-0.9 in 1000 cells in NB from urban areas; and 4.5+/-2.4 in 1000 cells in mothers and 2+/-1.5 in 1000 cells in NB from the agricultural area. The correlation between the frequency of MN in mothers and NB was significant (r=0.61, p<0.01). AChE levels of samples obtained both from group III mothers and from newborns were similar to those of group I. The Wilcoxon's rank-sum test was applied to measure differences in MN frequency; NB of group I were used as control group. A significant (p<0.01) higher frequency of MN (4+/-2) was found only in lymphocytes from NB from high-risk pregnancies. Data indicate that MN evaluation in umbilical cord samples might be useful in the identification of transplacental mutagens.

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 microg/mL. For the comet assay, following Singh's 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 microg/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 microg/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.

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.

[Giant chorioangioma of the placenta: report of a case]. / Corioangioma gigante de la placenta: informe de un caso.

Chorioangioma of the placenta is a benign vascular growth most frequently. Many small neoplasms are missed in routine examination of the placenta. The large tumors cause problems for the clinical outcome of the pregnancy or delivery or for the infant. We report a giant chorioangioma of the placenta of ten centimeters diagnosed in delivery by cesarean section in women with gestation third without complications. The benign vascular growth to fetal surface of the placenta. The histological variety was an angioblastic. In this case complication maternal or infant were not diagnosed.

[Relationship between maternal and neonatal iron stores]. / Relación entre las reservas de hierro maternas y del recién nacido.

OBJECTIVE: To establish the relationship of normal, low, and moderate blood iron values in mothers and their newborns. MATERIAL AND METHODS: A cross-sectional study was conducted among 163 pregnant women and their newborns, users of Hospital de Ginecología y Obstetricia número 15, Instituto Mexicano del Seguro Social, from Chihuahua, Mexico. The mothers' clinical histories were collected and analyzed; hemoglobin, hematocrit, and ferritin serum levels were measured in maternal and umbilical cord samples. Iron maternal stores were determined by ferritin (microgram/l) values as follows: low: < or = 11; moderate: 12-20; and normal: > or = 20.1. The Kruskal-Wallis test was used to establish differences among group; the chi-squared test to determine differences of proportions; and Pearson's correlation coefficient for assessing the association between maternal and newborn iron stores. RESULTS: A weak correlation between maternal and neonatal ferritin was found (r = 0.14, p = 0.07). Geometric means of neonatal ferritin for low, moderate, and normal maternal iron stores were 4.77, 4.85, and 5.02 respectively (p = 0.12). The maternal iron stores changed after iron supplementation (p = 0.01). CONCLUSIONS: Iron stores in mothers and their newborns are closely related. Women who take iron supplements during pregnancy have significantly higher iron stores at the end of pregnancy.

Impacto de una red comunitaria de apoyo psicosocial en la salud perinatal / Impact of a community network of psycho-social support on perinatal health

Objetivo. Determinar el impacto de una intervención comunitaria en la salud perinatal. Diseño. Intervención comunitaria. Emplazamiento. Nivel comunitario, en Chihuahua, México. Participantes. Se diseñó una intervención comunitaria incluyendo mujeres embarazadas (n = 1.233) antes de la semana 22 de gestación, de las cuales 1.148 concluyeron el seguimiento (6,74 por ciento de pérdidas; grupo de intervención, 261, y grupo control, 887), todas ellas residentes en las colonias periféricas de las 2 localidades. Mediante un sorteo aleatorio se asignaron a los grupos de estudio. Intervención. Consistió en 5 visitas previas al parto en las semanas 22, 26, 30, 34 y 38, así como una visita en el puerperio en los primeros 8 días, en las que se les proporcionó apoyo de tipo social y educativo. Al grupo control se le visitó en 2 ocasiones, semana 22 y puerperio, indicándoles continuar con las medidas habituales. Mediciones y resultados principales. Tasa de mortalidad perinatal, parto prematuro (< 37 semanas), bajo peso al nacer (< 2.500 g) y morbilidad perinatal. La tasa de mortalidad perinatal I fue menor en el grupo de intervención (3,8 por 1.000 nacidos vivos); en el grupo control fue de 13,1. No se encontraron diferencias estadísticamente significativas en parto prematuro, bajo peso al nacer y morbilidad perinatal. Conclusión. La intervención comunitaria proporciona apoyo a mujeres embarazadas con factores de riesgo psicosocial; sin embargo, no contribuye a disminuir de forma significativa el parto prematuro, el bajo peso al nacer o las complicaciones perinatales (AU)

[Acetylcholinesterase activity during pregnancy and in the newborn]. / Actividad de la acetilcolinesterasa durante el embarazo y en el recién nacido.

OBJECTIVES: Our purpose was to determine levels of acetyilcholinesterase (AchE) activity in total blood of women during pregnancy, and liverborns, and to analyze the correlation of the enzymatic activity between the capillary and venous sample. PATIENTS, MATERIAL, AND METHODS: We included 205 samples from pregnant (22), second (25), third trimester (36), full term pregnancy (65), non-pregnant women (28), and from Newborns (29). A bivaried analysis was used to analyse the AchE activity and its association with gestational age, body mass index, tobacco addiction, and use of pesticides at home, and hemoglobin concentration. RESULTS: Women at childbirth and at third trimester showed a significant increase in AcE levels by 5.75 + 1.15 U/mL and 4.98 +/- 0.87 U/mL respectively, respect to levels from non-pregnant women (4.59 +/- 0.79 U/mL). Activity in cord's blood was significatively minor (3.78 +/- 0.56 U/mL) compared with levels in non-pregnant women. There was no difference in AchE activity by tobacco addiction, hemoglobin levels, and use of insecticides at home. AchE activity by capillary and venous punction showed a correlation of 0.68 with p < 0.01 and IC 95% = 0.5171-0.8476. CONCLUSIONS: Enzymatic activity showed a normal distribution and could be considered like values from a non-exposure population. We determined that possible confounding factors like tobacco addiction and use of pesticides at home have no significant effects over AchE activity. Our results are important as reference values for studies about AchE activity in women from populations predominantly exposed to pesticides during gestation.

[Relationship between pregestational body mass index and body composition in the immediate puerperium]. / Relación entre el índice de masa corporal pregestacional y la composición corporal en el puerperio inmediato.

To determine the correlation between pregestational body mass index and certain body composition parameters measured by bioelectric impedance (percentage of fat weight, fat mass, and lean weight) and to compare the body composition of women in immediate puerperal period with non-pregnant women, a cross sectional study was done including 86 women in physiologic puerperal period and 90 healthy non-pregnant women, from the Instituto Mexicano del Seguro Social, in Chihuahua, Mexico, aged 16 to 40 years old. The variables considered were the body mass index (BMI) before pregnancy, percentage of fat, fat mass, lean weight, total water and bio-resistance. Body composition was measured by bioelectric impedance (BIO) from 4 to 12 hours after delivery. Correlation coefFicient for BMI and percentage of fat was r = 0.66 (p < 0.01), and for BMI and fat mass, it was r = 0.74 (p < 0.01). In non-pregnant women the total water was 35.5 +/- 5 L and in women in the immediate puerperal period 38.5 +/- 5 L (p < 0.01). In conclusion, BMI before pregnancy is a suitable predictor for body composition in the puerperal period. However, it does not discriminate important variables such as total body water, so it may be convenient to use BIA for surveillance of body composition during pregnancy.

[Impact of a community network of psychosocial support in perinatal health]. / Impacto de una red comunitaria de apoyo psicosocial en la salud perinatal.

OBJECTIVE: Determine the impact of a community intervention in perinatal health in, cities of the State of Chihuahua, Mexico. PATIENTS, MATERIAL AND METHODOLOGY: A community intervention was designed including pregnant women (n = 1233), and finally 1148 (6.74% of loss) group intervention (n = 261) control group (n = 887). Intervention consisted of five visits prior to delivery during the 22nd, 26th, 30th, 34th and 38th weeks, as well as a visit during the first 8 days in puerperium, providing social and educational support. In regards to the control group, they were visited in two different occasions, week 22 and purperium, indicating them to continue with their regular care. The outcome variables were perinatal mortality, premature birth (< 37 weeks), low weight at birth (< 2500 grams) and perinatal morbidity. RESULTS: Perinatal mortality rate was smaller in the intervention group 3.8 per 1000 born alive; perinatal mortality in the control group was 13.1. No statistically considerable difference was found in premature birth, in low weight at birth and in perinatal morbidity. CONCLUSION: Community intervention provides a support to pregnant women under psychosocial risk factors; nevertheless, it does not contribute to considerably decrease premature birth, low weight at birth or perinatal complications.

[Folic acid deficiency and its association with neural tube defects in northern Mexico]. / 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 Medico. Further investigations are necessary to determine the role of involved risk factors and implement adequate preventive measures.

[The efficacy of sleep hygiene measures in the treatment of insomnia]. / Eficacia de las medidas de higiene del sueño en el tratamiento del insomnio.

In order to compare the efficacy of sleep hygiene to the effect of a placebo and to a treatment with benzodiazepines in psychophysiologic insomnia. We performed a clinical assay in 150 patients from a primary care unit in Chihuahua, Chih. Patients were allocated in three groups according to a non-systematic random procedure. Patients from group I received an instructive booklet with 10 recommendations about sleep hygiene, group II received placebo, and group III benzodiazepines. Patients were interviewed three weeks after the maneuver was delivered. The effect of the maneuver was classified as success or failure. In Group I, the result was of 65% success vs 35% failure; in Group II. 50% success vs. 50% failure; and group III, 73% success vs. 23% failure (p = 0.06). In conclusion, all three types of treatment have similar efficacy in the management of insomnia. Sleep hygiene is effective and does not have risk of secondary effects. Thus, we recommend sleep hygiene as the therapy of first choice for insomnia.