The cohort of children born in Pelotas in 2015 is the fourth generation under study in the largest longitudinal research in Latin America, the Pelotas Birth Cohort Program.

With an eleven-year interval between the cohorts, the 2015 cohort was planned to continue collecting information compatible with that obtained from the three previous cohorts, and to expand upon these by also addressing the gestational period.

The initial phases of the study are to deepen the scientific knowledge on the impact of maternal life, intrauterine environment and first years of life on newborn health.

Scheduled in waves, the 2015 cohort reaches the children’s second year of life with the accomplishment of the previous follow-ups:

Pre-natal: Teams of interviewers have made daily visits to the places of possible inflow of pregnant women in Pelotas, in order to identify the ones with childbirth expected by 2015. Among these places were clinical analysis laboratories, ultrasound clinics, polyclinics, and basic health units, outpatient clinics in hospitals and universities, and private medical offices. The study includes interviews with pregnant women, varying the type of questionnaire according to gestational age. If the pregnant woman has been contacted before the 16th week of gestation, the initial contact questionnaire was applied and a new interview was scheduled for the window at the 20th week of gestation. If the first contact has occurred after the 16th week, the questionnaires corresponding to the two encounters were applied in a single interview. The focus was to obtain a series of data on prenatal care and life habits and evaluation of the oral health of pregnant women (see Prenatal Questionnaires tab).

Perinatal: From January 1 to December 31, 2015, the four hospitals in the city of Pelotas were monitored daily and each birth was informed to the research team. All newborns with at least 500 g or 20 weeks of gestational age were considered eligible for the perinatal study. Mothers were interviewed a few hours after delivery and newborns were evaluated by the research team using a protocol similar to that used in previous cohorts. Some information was also collected in the medical records of mothers and newborns, regarding medications used during admission to labor (see the Perinatal Questionnaire section).

3 months: From April 2015 to March 2016, at three months of age of the cohort participants, all the children and their mothers were visited at home to evaluate neonatal and early childhood events (breastfeeding, morbidity, mortality, among others) and to collect anthropometric measures such as weight, length and cephalic, thoracic and abdominal perimeters. Maternal anthropometric measures and data on physical activity were also collected (see Three Months Questionnaire tab).

1 year: At the one year follow-up, the mother or caretaker was interviewed and the child examined at home. Information was collected on socio-economic and demographic characteristics, health care utilization, feeding practices, lifestyles and child growth, development and morbidity since birth. Separate questionnaires on maternal health and exams on child development were also administered.

2 years: When children are about to turn two years old, all mothers are contacted by telephone to schedule the follow-up visit. For the first time, the series of interviews and exams is being held at the headquarters of the Center of Epidemiological Research. Children undergo a battery of exams such as anthropometric tests, saliva collection, and psychomotor and cognitive development assessment. Mothers are interviewed on socioeconomic and demographic characteristics, health care utilization, feeding practices, dietary habits, physical activity frequency, lifestyles and mental health. At the end of the visit, accelerometers are placed on the participants’ wrist to be kept with children for 4 days and with mothers for 8 days.