Introduction: Gestational weight gain is an important modifiable factor known to influence fetal outcomes including birth weight and adiposity. Leptin is normally correlated with adiposity and is also known to increase throughout pregnancy, as the placenta becomes a source of leptin synthesis. Several studies have reported positive correlations between cord blood leptin level and either birthweight or size for gestational age, as well as body mass index (BMI). Objective: To determine the correlation of prenatal leptin concentration in pregnant adolescents with their gestational weight gain, postpartum weight retention, and weight/length of their newborn. Methods: A cohort study was conducted on pregnant Mexican adolescents from Gestational Week 26–28 to three months postpartum (n = 168 mother–child dyads). An anthropometric assessment was made of each pregnant adolescent, and the serum level of leptin and the intake of energy were determined. The newborn was evaluated each month during postpartum. Clinical records were reviewed to obtain sociodemographic data. Bivariate correlations, tests for repeating measurements and logistic regression models were performed. Results: Leptin concentration gradually increased during the third trimester of pregnancy. At Gestation Week 36, leptin level correlated with gestational weight gain. When comparing adolescents that had the lowest and highest concentration of leptin, the former presented a mean of 6 kg less in gestational weight gain (inter-subject leptin concentration, p = 0.001; inter-subject energy intake, p = 0.497). Leptin concentration and gestational weight gain exerted an effect on the weight of the newborn (inter-subject leptin concentration for Week 32, p = 0.024; inter-subject gestational weight gain, p = 0.011). Newborn length was associated with leptin concentration at Week 28 (leptin effect, p = 0.003; effect of gestational weight gain, p = 0.722). Conclusions: Pregnant adolescents with leptin concentration over 20 ng/mL showed a greater gestational weight gain. Leptin concentration correlated with length and weight of the newborn.

Introduction: Institute of Medicine gestational weight gain recommendations are based on body mass index (BMI) status using adult cut-off points for women of all ages, even though adolescents have specific criteria, like WHO and CDC, so adolescents can receive inadequate weight gain recommendations. Objectives: To estimate the proportion of classification disparity between the three criteria (WHO, CDC and IOM) of pre-pregnancy BMI status; and to analyze neonatal outcomes according to weight gain recommendation based on pre-pregnancy BMI using the three criteria. Methods: Follow-up study in pregnant adolescents 12–19 years. Sociodemographic, anthropometric and pregnancy data were obtained. Percentage of pre-pregnancy BMI classification disparity was calculated between three criteria. Gestational weight gain was categorized in adequate, low and high according to IOM. Regression models were used to analyze negative neonatal outcomes. Results: 601 pregnant adolescents were included, mean age was 16±1.4 years. For pre-pregnancy BMI classification, 28.5% had classification disparity using IOM vs WHO, and 14% when comparing IOM vs CDC. Greater classification disparity was observed as BMI increased. When using WHO categories, a high weight gain was associated with increased risk of having a low birth weight baby (OR: 1.91, CI95%: 1.03–3.53). For CDC criteria, a low weight gain was associated with increased risk of having a preterm baby (OR: 2.65; CI95%: 1.16–6.08) and a high weight gain was associated with low birth weight (OR: 2.10; CI95%: 1.10–4.01). For IOM criteria, a weight gain either low or high were associated with increased risk of low birth weight and preterm birth. Conclusion: There is pre-pregnancy BMI classification disparity using criteria for adolescents compared to adult criteria. Nevertheless, with WHO and CDC only a high gestational weight gain was a risk for negative neonatal outcome. It is important to have a BMI classification system for adolescents that better predicts neonatal outcomes.

During pregnancy, adolescents experience physiological changes different from adults because they have not concluded their physical growth. Therefore, maternal and neonatal outcomes may not be the same. This paper aimed to analyze the association between pregestational BMI (pBMI) and gestational weight gain (GWG) with maternal and neonatal outcomes in adolescent and adult pregnant women. The authors performed an observational study that included 1112 women, where 52.6% (n = 585) were adolescents. Sociodemographic information, pBMI, GWG, neonatal anthropometric measures, and maternal and neonatal outcomes were obtained. Adolescent women had a mean lower (21.4 vs. 26.2, p ≤ 0.001) pBMI than adults and a higher gestational weight gain (12.3 vs. 10.7 kg, p ≤ 0.001). According to Poisson regression models, gestational diabetes is positively associated with insufficient GWG and with pregestational obesity. Furthermore, the probability of developing pregnancy-induced hypertension increased with pBMI of obesity compared to normal weight. Preeclampsia, anemia, and preterm birth were not associated with GWG. Insufficient GWG was a risk factor, and being overweight was a protective factor for low birth weight and small for gestational age. We conclude that pBMI, GWG, and age group were associated only with gestational diabetes and low birth weight.

Pregnant adolescents’ diet and eating habits are inadequate; however, their association with gestational weight gain (GWG) is uncertain. We aimed to analyze whether there is an association between dietary and nutrient intake and eating habits with GWG among pregnant adolescents and their offspring’s birth weight. A longitudinal study was performed with 530 participants. We assessed GWG and applied several tools, such as a food frequency questionnaire and 24-h recall, to obtain dietary and nutrient intake and eating habits. The birth weight of adolescents’ offspring was registered. Later, we performed crude and adjusted Poisson models. The mean age was 15.8 ± 1.3 years. Of all food groups, the lowest frequency of adequate intake corresponded to vegetables (7%) and legumes (10.2%). Excessive (36.8%) and insufficient (40.9%) GWG were observed. Pregnant adolescents with inadequate legumes intake increased the probability of excessive GWG: (PR 1.86 95% CI 1.00–3.44). Cereals and grains were positively associated with GWG: (PR 1.65, 95% CI 1.18–2.29). Energy, macronutrient intake, and eating habits were not associated with GWG. Offspring’s small gestational age (SGA) increased when pregnant adolescents had inadequate sugar-sweetened beverages intake: PR (1.58, 95% CI 1.01–2.49) and when pregnant adolescent watched television (TV). In our sample of Mexican adolescents, dietary and nutrient intake and eating habits were inadequate. Excessive dietary intake from cereals, grains, and animal-sourced foods along with insufficient legumes were associated with excessive GWG. Watching TV while adolescents ate was associated with the birth weight of the offspring.

Background: Gestational weight gain below or above the Institute of Medicine recommendations has been associated with adverse perinatal and neonatal outcomes. Very few studies have evaluated the association between serum and red blood cell folate concentrations and gestational weight gain in adolescents. Additionally, zinc deficiency during pregnancy has been associated with impaired immunity, prolonged labor, preterm and post-term birth, intrauterine growth restriction, low birth weight, and pregnancy-induced hypertension. Objective: The purpose of our study is to evaluate the association between serum concentrations of zinc, serum folate, and red blood cell folate, with the increase in gestational weight and the weight and length of the newborn in a group of adolescent mothers from Mexico City. Results: In our study, 406 adolescent-neonate dyads participated. The adolescents’ median age was 15.8 years old. The predominant socioeconomic level was middle-low (57.8%), single (57%), 89.9% were engaged in home activities, and 41.3% completed secondary education. Excessive gestational weight gain was observed in 36.7% of cases, while insufficient gestational weight gain was noted in 38.4%. Small for gestational age infants were observed in 20.9% of the sample. Low serum folate (OR 2.1, 95% CI 1.3–3.3), decreased red blood cell folate (OR 1.6, 95% CI 1.0–2.6), and reduced serum zinc concentrations (OR 3.3, 95% CI 2.1–5.2) were associated with insufficient gestational weight gain. Decreased serum zinc levels (OR 1.2, 95% CI 1.2–3.4) were linked to an increased probability of delivering a baby who is small for their gestational age. Conclusions: Low serum folate, red blood cell folate, and serum zinc concentrations were associated with gestational weight gain and having a small gestational age baby. Both excessive and insufficient gestational weight gain, as well as having a small gestational age baby, are frequent among adolescent mothers.