Excessive Weight Loss in the Perinatal Period: A Case-Control Study

Background: Weight loss is expected in the first days of life. There is lack of population-based data on risk factors for newborn’s weight loss.

Objective: Determine factors associated with weight loss higher than 10% at postpartum discharge.

Methods: Prospective case-control study conducted in a second-level hospital during a five-month period, including all the newborns with weight loss >10% at the third day of life. Gestational age less than 35 weeks, birth weight less than 1900g and need for intermediate/intensive care were exclusion criteria. Controls were matched by gestational age, type of delivery and sex. Clinical and demographic variables, and occupancy levels were analyzed. For statistical analysis, we used t-student and qui-square tests (p-value

Results: A total of 59 newborns were included (6.1% of total deliveries). The majority (96.6%) was full-term and 44.1% were delivered via cesarean. Concerning birth weight, no significant difference between groups of cases and controls was found. Mean percentage of weight loss was 11.0% in the case group. There was a higher percentage of gestational diabetes and hypertension during pregnancy in the study group, but the difference wasn’t significant (10.2 vs 1.7%, p 0.051; 8.5 vs 1.7%, p 0.094, respectively). Parents were older in the case group (median age 33 vs 31 years for mothers and 35 vs 33 years for fathers), without significant difference (p 0.294 and p 0.055). We found a significant higher occupancy rate of the nursery (66.8% vs 60.0%) in the group of cases (p 0.012). No significant difference was found regarding number of siblings, maternal active smoking, psychiatric conditions or ethnicity.

Conclusion: Occupancy rate of the nursery was the only factor with a strong association with excessive weight loss in our study, demonstrating the importance of nurse counseling of mothers during the first days of the newborn’s life.