Retrospective analysis of age-adjusted body mass index among pre-pregnant women in the Lithuanian urban area during three decades

Background: The prevalence of maternal obesity at the beginning of pregnancy is increasing. However, there are some studies reporting the stabilisation of obesity epidemic or even the downward trend in the general population.

Objective: To determine the prevalence of overweight and obesity in Lithuanian pre-pregnant women during 3 decades.

Methods: This observational retrospective study included a sample of 2827, women aged 18-44 years who gave birth in 1987-1989, 1996-1997 and 2007-2010: 861 (30.5%), 995 (35.2%) and 971 (34.3%), respectively. All women were divided into groups by body mass index (BMI) calculated from self-reported weight and height, and age reported during the first antenatal visit. Quantitative parametric variables were expressed as mean and SD; qualitative variables, as absolute numbers (n) and percentage (%). For parametric data, analysis of variance (ANOVA) was used. Differences were considered statistically significant at p<0.05.

Results: The prevalence of overweight and obesity among women aged 18-24 years decreased from 20.9% in 1987-1989 to 9.5% in 1996-1997 but increased to 15.7% in 2007-2010; among women aged 25-34 years, decreased from 35.5% in 1987-1989 to 23% in 1996-1997 and to 22.4% in 2007-2010; and among women aged 35-44 years decreased from 64.9% in 1987-1989 to 34% in 1996-1997 but increased to 45.3% in 2007-2010. BMI increased with an increasing age (r=0.254, p<0.05). Analysis by separate periods (1987-1989, 1996-1997 and 2007-2010) revealed a positive correlation between BMI and age at the first antenatal visit in all periods (r=0.325, p<0.01; r=0.266, p<0.01; and r=0.210, p<0.01, respectively).

Conclusions: The prevalence of overweight and obesity among pre-pregnant women tended to decrease in the Lithuanian urban area during 3 decades. A slight increase in overweight and obesity documented in 2007-2010 compared with 1996-1997 most likely was caused by older maternal age.