Differences in Birthweight Outcomes: A Longitudinal Study Based on Siblings

Abstract

Objectives: We investigate the differences in birthweight between first- and second-borns, evaluating the impact of changes in pregnancy (e.g., gestational age), demographic (e.g., age), and social (e.g., education level, marital status) maternal characteristics. Data and Methods: All analyses are performed on data collected in Umbria (Italy) taking into account a set of 792 women who delivered twice from 2005 to 2008. Firstly, we use a univariate paired t-test for the comparison between weights of first- and second-borns; Secondly, we use linear and nonlinear regression approaches in order to: (i) evaluate the effect of demographic and social maternal characteristics and (ii) predict the odds-ratio of low and high birthweight infants, respectively. Results: We find that the birthweight of second-borns is significantly higher than that of first-borns. Statistically significant effects are related with a longer gestational age, an increased number of visits during the pregnancy, and the gender of infants. On the other hand, we do not observe any significant effect related with mother’s age and with other characteristics of interest.

Sex ratio and maternal age in a natural fertility, subsistence population: Daughters, sons, daughters

“…Thus, young mothers could be facing energetic trade‐offs between the completion of their own biological maturation and the conception, gestation, and raising of offspring during those 4 years. Consistent with this proposition, first born babies traditionally have lighter birthweight compared to later born ones (Bacci, Bartolucci, Chiavarini, Minelli, & Pieroni, ; Savage et al, ). This trade‐off may help explain the bias toward daughters observed among younger mothers in our subsistence population.…”

Born to Take Risk? The Effect of CEO Birth Order on Strategic Risk Taking

“…Positive relationship between birth order and height disadvantage Bacci, Bartolucci, Chiavarini, Minelli, and Pieroni (2014) Italy 8 Positive relationship between birth order and birth weight Emerson and Souza (2008) Brazil 9 Positive relationship between birth order and school attendance Davis (1997) Canada 10 Negative relationship between birth order and status orientation Juon et al (1995) South Korea 11 Later-borns more likely to smoke than earlier-born boys Rohde et al 2003 evolutionary theory perspective, which is based on the concept of evolution-change over time in living structures among species (Buss, 2007). Darwin (1968) is credited with introducing evolutionary theory, but other scholars set the stage for his research.…”

Preterm Birth: Analysis of Longitudinal Data on Siblings Based on Random-Effects Logit Models

“…Some variables, such as some partner’s characteristics, are ignored in the study due to missing data; birthweight is also ignored as it is an outcome of pregnancy occurring in conjunction with gestational age [a recent study that relates birthweight to gestational age is illustrated in Ref. (20)]. We specify that, having dropped variables with missing data, the remaining variables used in the study do not present problems of unobserved values.…”