Twin births in Yucatan, Mexico during 2008-2020: trends in maternal sociodemographic factors and differences in birth weight and length according to sex of co-twin.

Background: Over the years, there has been a noticeable increase in the incidence of multiple pregnancies, due in part to the increased use of assisted reproductive technologies in recent years. The increase in twin pregnancies constitutes a public health challenge due to the adverse outcomes sometimes they entail. Twin pregnancies inherently carry a higher risk of complications, and one of the critical associated factors is the risk of low birth weight. Twin birth weight discordance among different populations can be attributed to differences in non-shared environmental influences. The presence of two or more fetuses in the uterus may lead to an unequal distribution of nutritional and oxygen resources, increasing the likelihood that at least one of the twins will experience insufficient fetal development. Other factors, such as ethnicity, genetics, sociodemographic characteristics, gestational age, parity, and chorion type, have also been related to the birth weight discordance in twin pregnancies. However, it is unclear to what extent the associations between these factors can explain the differences in birth and length size. The frequency of twin births varies among populations and over time, so it is crucial to gain a deeper understanding of the factors contributing to the rise in the twinning rate. The official records of twins continue to make significant contributions to our understanding of the causes of individual differences, and new twin registries are still being created. The recent availability of data from developing countries allows the analysis of trends in regions with sociodemographic and reproductive profiles. Obtaining a more comprehensive understanding of the epidemiology, as well as the related morbidity and mortality, is clinically crucial. Objectives: The aim of the study was to describe the trends of twin births in Yucatan, Mexico during 2008-2021, analyze their association with maternal sociodemographic factors, and compare birth outcomes between types of twin pairs: female-female, male-male, and female-male. Methods: A retrospective cohort analysis was conducted using data from the Mexican Ministry of Health, encompassing information on all births registered in the State of Yucatán, Mexico, from 2008 through 2021. The data was obtained from both public and private hospitals. The variables, including date of birth, sex, gestational age, birth weight and length of newborns, mother´s date of birth, educational level, and number of previous live offspring, were extracted from each dataset. Multiple births (three or more) were excluded from the study. We graphically analyzed the rates (per 1000 births) and percentages of twins according to maternal age, education level, and parity during the study period. A multiple logistic regression model was used to analyze the association between maternal sociodemographic factors and the occurrence of twin births. Comparisons of the gestational age and birth weight and length between types of twin pairs were performed using analysis of variance. Results: A total of 478,118 live births, including 1.4% twins (accounting 6,766 twin births), were analyzed. The rates increased from 11.21 during 2008-2011 to 13.34 during 2012-2017 and reached 20.08 in 2019. The percentages increased in women aged ≥30 years and those with higher educational levels. Older maternal age (coefficient = 0.03; OR = 1.03, per each year), greater education level (coefficient = 0.55 and OR= 1.74 for medium and coefficient = 1.05; OR = 2.57 for high level, compared with no education) and higher parity (coefficient= 0.26; OR = 1.30 per each previous offspring) increased the odds for having twins. Twins' male-male showed a slightly increased of preterm birth than a co-twin female. Opposite-sex twins showed measurable but small increases in birth weight and length compared with same-sex twins. Conclusion: The rate of twins in Yucatan increased substantially during 2008-2020 in specific sociodemographic groups. Opposite-sex twins were slightly larger than same-sex twins at birth.

Concordancia del IMC y la percepción de la imagen corporal en adolescentes de una localidad suburbana de Yucatán / Concordance of the body mass index and the perception of body image in adolescents in Yucatán

Resumen Introducción Los problemas de la imagen corporal asociados con los riesgos de trastornos alimenticios entre los adolescentes, en particular, la anorexia nerviosa y la bulimia, son considerados temas de salud emergentes a nivel mundial. Las consecuencias que conllevan son físicas, psicológicas y sociales. Objetivo Determinar la concordancia entre el índice de masa corporal y la percepción de la imagen corporal en un grupo de adolescentes. Materiales y Métodos Estudio cuantitativo, observacional, transversal realizado en 84 alumnos, 54.1% hombres y 45.9%, mujeres, con edades entre 10 y 17 años, que cursaban educación básica y secundaria en una localidad suburbana de alta marginación, en Yucatán. Se auto-administró a los estudiantes, el pictograma de Stunkard, para registrar la percepción de la imagen corporal. Para calcular el índice de masa corporal (IMC) se registraron medidas antropométricas de peso y talla, usando una báscula digital marca Tanita, modelo TBC 310 y un estadímetro marca SECA de 2 metros de longitud. Los puntos de corte fueron los establecidos por la Organización Mundial de la Salud. Resultados Los hallazgos, respecto a la percepción de la imagen corporal, mostraron una concordancia insignificante (k= 0.067, p< 0.5); en mujeres es baja, con un valor de k= .223; se perciben normales aun cuando presentan bajo peso, mientras que, las que presentan obesidad, subestiman su estado. En cuanto a los hombres, en los casos de obesidad, la imagen y el IMC son coincidentes, aunque, al mismo tiempo, subestiman la percepción corporal en bajo peso.

Abstract Introduction Body image problems associated with the risk of eating disorders such as anorexia nervosa and bulimia, are considered emerging health issues among adolescents around the world. These problems have both physical, psychological and social consequences. Objective To determine the correlation between body mass index and the body image perception in a group of teenagers. Material and Methods A quantitative, observational, cross-sectional study was carried out in 84 students, 54.1% men and 45.9% women with an age range between 10 and 17 years who were attending primary or secondary school education in a suburban town of high marginalization in Yucatan. Self-applicable Stunkard pictogram was used to record the body image perceptions. To calculate the body mass index (BMI) anthropometric measurements of weight and height were recorded, using a Tanita brand digital scale, TBC model and a stadiometer SECA 310 2 meters length. The cut-off points were those established by the World Health Organization. Results The findings regarding the perception of body image showed no significant concordance (k = 0.067, p <0.5); for women was a low value of k = 0.223, they perceive themselves as normal despite their low weight, and those with obesity underestimate their status. In the group of men, in cases of obesity, image and BMI are coincident while a body perception underestimates low weight. Conclusion It is important to take into the nutritional diagnosis, contents of emotional aspects as self-esteem and feelings that manifest teenagers about their body image for comprehensive preventive care.