Dora Virginia Chávez-Corral

Relación entre los Niveles de Ácido Fólico, Vitamina B12 y Homocisteína Materna y los Defectos de Tubo Neural y Labio Hendido

El objetivo del trabajo fue determinar la asociacion entre los niveles de acido folico, vitamina B (Vit B12) y homocisteina (Hci) maternos, con defectos del tubo neural (DTN) y labio hendido (LH) con y sin paladar hendido (c/s PH). Se realizo un estudio tipo casos y controles. Casos, con diagnostico de DTN y LH c/s PH (n=36) y cuatro controles hospitalarios por caso (n=141). Se incluyeron recien nacidos (RN) y lactantes hasta 12 meses de edad. Las variables de pareamiento fueron: edad del RN o lactante, etniay hospital. Un 23% de etnia Tarahumara y 77% mestizos. Se determino acido folico intraeritrocitario (AFI), plasmatico (AFP) y Vit B12 por radioinmunoensayo, la Hci por inmunoensayo de fluorescencia polarizada. Se considero deficiencia si el AFI fue 15 |J.mol/L. El analisis estadistico se realizo a traves de regresion logistica condicionada. Se identifico deficiencia de AFI en el 22% de las mujeres cuyos recien nacidos o lactantes presentaron algun tipo de defecto congenito y en el 12% de los controles. La relacion entre AFI y DTN, LH c/s PH ajustada por edad materna, exposicion a plaguicidas y zona de residencia fue RM 2,96 (IC 95% 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.

Placental maturity, hypertensive disorders of pregnancy and birth weight

Objectives: To compare maturity of placentas from women with hypertensive disorders with those from normotensive pregnancies and to determine the relationship between placental maturity (PM) and the diagnosis of small-for-gestational-age (SGA) in the newborns. Materials and methods: We examined placental stained specimens from women with normotensive pregnancies (n = 100), diagnosis of gestational hypertension (n = 38), mild (n = 10), or severe preeclampsia (n = 34) in an optical microscope. Placental Maturity Index (PMI) was calculated as the number of vasculo-syncytial membranes (VSM) in 1 mm2 divided by VSM thickness (µm). Hypermaturity was defined as >90th percentile of the PMI from placentas of normotensive pregnancies. Newborns were classified as SGA, adequate-for-gestational-age (AGA) or large-for-gestational-age (<10th, 10–90th, and >90th percentile from weight for gestational age reference tables, respectively). Results: PMI in preeclamptic women (taking together mild and severe preeclampsia, PMI = 43.4 ± 1.6) was significantly higher than in normotensive women (PMI = 36 ± 2, p = 0.045). Hypermaturity was more frequent (p < 0.05) in placentas from women with preeclampsia than in those from normotensive women only in preterm pregnancies (<37 weeks), but not in those at term (p = 0.41). The frequency of hypermaturity in placentas from women with gestational hypertension was not statistically different than in normotensive women. Hypermaturity was also more frequent in placentas from SGA (OR = 2.63, p < 0.05) than in AGA newborns. Conclusion: The PMI was increased in preeclampsia, but not in gestational hypertension. Placental hypermaturity was also associated with the diagnosis of SGA in newborns. PM might have a role in the relationship between maternal factors and SGA.

Birth weight in children with birth defects

BACKGROUND Birth defects (BDs) are a serious public health problem in Mexico. The objective of this paper was to identify the frequency of newborns (NBs) that are born small for gestational age with a birth defect. MATERIALS AND METHODS A cross-sectional study of NBs from hospitals part of the Mexican Institute of Social Security in Chihuahua, Mexico, was conducted. NBs were classified according to the presence or absence of a BD and according to their weight percentile using regional standards of birth weight. RESULTS NBs diagnosed with (n = 263) or without BDs (n = 64,626) were included in this study. A greater proportion of NBs small for gestational age were identified in cases involving BDs (20%), compared with NBs without BDs (9%). Moreover, the average decrease in birth weights of NBs with BDs associated with their digestive system was 210 grams (95% confidence interval [CI], -436/-12), with their genital organs 440 grams (95% CI, -730/-151), involving chromosomal abnormalities 230 grams (95% CI, -435/-26), or with their musculoskeletal system 289 grams (95% CI, -43/-147) according to the gestational age, sex, and condition of the NB (p < 0.05). CONCLUSIONS A greater proportion of NBs with BDs were associated with a low birth rate for their gestational age. In addition, some BDs were found to be associated with an impaired birth weight more often than others This suggests that clinical decisions regarding NBs with congenital defects and a lower birth weight for their gestational age should be diagnosed and treated for additional nutritional considerations as needed. Birth Defects Research (Part A), 2011.

Body composition and newborn birthweight in pregnancies of adolescent and mature women

Teenage pregnancy has been associated with adverse effects for the mother and the newborn (NB). In order to compare body composition (BC) between adolescents (Ad) and mature women (MW) during pregnancy and to determine the difference in birthweight and perinatal morbidity, pregnant Ad (n=40) and MW (n=227) were studied. BC changes between the second and third trimesters were determined by multifrequency bioelectrical impedance analysis, and birthweight and NB morbidity were evaluated. During the second and third trimesters of the pregnancy, fat mass was lower in the Ad group [16 kg (13-19)] than in the MW group [22 kg (17-27)] (P<0.01; median and quartiles 1-3). Fat-free mass increased by 3.09 kg (2.29-4.20) and 2.20 kg (1.0-3.59) (P≤0.01), and total body water increased by 2.77 L (0.84-4.49) vs. 2.04 L (0.55-3.89) (P=0.36), in the Ad and MW groups, respectively (median and quartiles 1-3). Birthweight was not significantly different between NBs of Ad (3223 ± 399 g) and NBs of MW (3312 ± 427 g, P=0.22). The youngest Ad (<18 year old, n=8) had NB with lower birthweight than MW (3031 ± 503 g, P=0.06). NBs of Ad mothers showed a non-significant trend towards a higher rate of morbidity relative to the NBs of MW. In conclusion, the BC of Ad differs from that of MW during pregnancy. In addition, the NB infants of Ad mothers tended to have a lower birthweight than those from MW, a result that suggests that the Ad should be in strict prenatal control.

Morfología de la Placenta en Recién Nacidos con Defecto Congénito

RESUMEN: 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 cas s y n= 0 controles sin DC. Los casos se clasificaron de acuerdo a la presencia de DC aislado (n=17) o múltiple (n=8). Se incluyeron recié n nacidos/óbitos (RN) con una edad gestacional (EG) > 20 semanas. Se excluyeron embarazos gemelares. Se recolectó información sob re 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 ín dice de madurez placentaria (IMP), calculado dividiendo el número de membranas vásculo sinciciales en 1 mm 2 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.

Defectos del Tubo Neural y de Labio y Paladar Hendido: un Estudio Morfológico

El objetivo del trabajo fue realizar una evaluacion morfologica externa de recien nacidos (RN) y lactantes con diagnostico de defectos de tubo neural (DTN) y labio hendido c/s paladar hendido (LH c/s PH) para determinar el tipo de defecto, ubicacion, extension, clasificacion y evaluar la proporcion de RN con retardo del crecimiento intauterino (RCIU) y lactantes desnutridos. Estudio descriptivo. Se estudiaron 36 ninos desde su nacimiento hasta los 12 meses de edad; 20 con DTN y 16 con LH c/s PH. El estudio se realizo en cinco hospitales de la ciudad de Chihuahua, Mexico. Se hizo una evaluacion morfologica externa y antropometria de los ninos. Los DTN se clasificaron como lesiones abiertas y cerradas, como defectos altos o bajos, segun el modelo de sitios multiples y por la CIE-10. Los LH c/s PH se clasificaron como unilaterales o bilaterales, completos e incompletos y como aislados o multiples. Se determino RCIU en los RN y desnutricion en los lactantes. El analisis estadistico se realizo 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% fueron mielomeningocele y correspondian a lesiones abiertas. El 85% se localizaron a nivel alto. En el modelo de cierres multiples, el Z1 fue el 80%. Los LH c/s PH mas frecuentes fueron aquellos con hendidura completa (50%). El 35% de los RN con DTN tuvieron RCIU y el 67% de los lactantes presentaron desnutricion. Es importante conocer los mecanismos del desarrollo de las anomalias congenitas ya que esto permite precisar el momento en que ocurrio la falla y permite estudiar los factores predisponentes, con lo cual se puede ofrecer asesoramiento genetico para una posible prevencion.

Folate transporter expression in placenta from pregnancies complicated with birth defects

BACKGROUND Folate plays a fundamental role for fetal development, participating in cell division, embryogenesis, and fetal growth. The fetus depends on maternal supply of folate across the placenta. The objective of this study was to compare the expression of Folate Receptor-α (FR-α), Reduced Folate Carrier (RFC), and Proton Coupled Folate Transporter (PCFT) in placentas from pregnancies complicated with birth defects (BD) and controls. METHODS Case-control study, including placentas of BD-complicated pregnancies (n = 25) and a control group (n = 25). We determined the placental expression of FR-α, RFC, and PCFT by immunohistochemistry. Optical density was measured to obtain a relative quantification of the expression. RESULTS The expression of PCFT was greater in placentas from pregnancies complicated with BD than in those from the control group (p < .01). The expression of FR-α and RFC was not different between groups. CONCLUSION The expression of PCFT in placentas from BD-complicated pregnancies is increased, possibly as an adaptive response to increase the folate flux at the maternal-fetal interface.