Boletín médico del Hospital Infantil de México
versión impresa ISSN 1665-1146
FLORES HUERTA, Samuel y MARTINEZ SALGADO, Homero. Birth weight of male and female infants born in hospitals affiliated with the Instituto Mexicano del Seguro Social. Bol. Med. Hosp. Infant. Mex. [online]. 2012, vol.69, n.1, pp. 30-39. ISSN 1665-1146.
Background. Birth weight is a fundamental indicator for evaluating the health of children. In order to determine whether or not an infant's birth weight is appropriate, we compared the reference standards in accordance with gestational age and gender in newborns from hospitals affiliated with the Mexican Social Security Institute, using a population-based design. Methods. From June 2000 to March 2002, from 33 hospitals affiliated with the Mexican Social Security Institute, the weight of 24,627 newborns (12,701 males and 11,926 females) was evaluated with an electronic scale. Infants were from the following regions of Mexico: northern, central, Mexico City and southern. Using SPSS v.11.5 for Windows, the weight of the total sample was analyzed from weeks 28 to 42 to build the following percentiles: 10th, 25th, 50th, 75th and 90th, as well as the average and standard deviation. The same values were obtained for each of the above-mentioned regions but only for those infants with 35-42 weeks of gestational age. Results. Male newborns are heavier than females. The weight of newborns from northern Mexico is higher than the birth weight of newborns from other regions of Mexico. Newborns from southern Mexico have the lowest birth weight. Comparing these values with other Mexican studies, it is considered that the birth weight of newborns increased per week ~100 g after 37 weeks of gestation for the 50th percentile and ~139 g per week for the 10th percentile. Conclusions. Growth data of infants from a sample population is proposed as a benchmark to evaluate the birth weight of Mexican newborns.
Palabras llave : birth weight; percentiles; gestational age.