This study seeks a better understanding of the pathogenesis of asthma in early life. The aim of this project is to determine whether the offspring of obese mothers at 3 years of life have increased the risk of asthma compared to children whose mothers were not obese and whether this increased risk is associated with a programming altered immune reactivity at birth.

The general objectives of this study are:

1. To determine whether the increased risk of asthma in children born from a pre-pregnant obese mother can be observed at 3 years of life and whether this increased risk associated with altered plasma levels of immune mediators at birth.
2. To explore in children born from pre-pregnant obese mother whether monocyte physiology and M1-M2 polarization present an altered response and expression of asthma-related immune-modulations at birth.
3. To study in neonates born from pre-pregnant obese mother whether the in vitro expression of TNFα, IL12, IL-10 and IL-4Rα in monocytes associates with changes in the DNA methylation status in the promoter regions of those genes.

The study is performed in accordance with the Helsinki Declaration, and the study protocol was accepted by Institutional Review Boards at School of Medicine of the Pontificia Universidad Católica de Chile.

Inclusion Criteria:

• Women who receive care in any of the 12 public health care centers in La Florida and Puente Alto and give birth in the Sotero del Río Hospital.
• Singleton pregnancy of fewer than 14 weeks of gestation at the first antenatal visit.
• 18 years or older

Exclusion Criteria:

• Pregnant women with overweight (BMI 25-30) before 14 weeks.
• Women that have a premature birth, cardio-respiratory disorder or neurological defects of the neonate.
• Women that develop gestational diabetes and hypertension during pregnancy

The recruitment of participants was performed in the Sotero del Rio Hospital at Santiago. Women that were obese (BMI>30) or normal weight (BMI<25) at their first antenatal visit were invited to participate in the study at the moment of delivery.

Questionnaires: Information regarding birth outcomes, maternal and paternal history of asthma and allergy, as well as environmental conditions at home (pet ownership, indoor smoking, heating system, and so on) was collected using a questionnaire at the moment of recruitment.

Follow-up questionnaires by phone are completed every 6 months. These questionnaires collect information regarding diagnosis of asthma/allergy and acute respiratory illness, environmental conditions, and relevant confounding variables