Does Excess First- or Second-Trimester Weight Gain Predict Excess Total Gestational Weight Gain? A Multicentre...

Area of Science:

• Obstetrics and Gynecology
• Maternal Health
• Public Health Nutrition

Background:

• Early excess gestational weight gain (GWG) is a growing concern.
• International studies suggest early GWG may predict total excess GWG.
• Canadian data on this association were previously lacking.

Purpose of the Study:

• To determine if early (first- and second-trimester) excess GWG predicts total excess GWG in a Canadian population.
• To analyze the predictive value of early GWG for total excess GWG based on pre-pregnancy body mass index (BMI).

Main Methods:

• Secondary analysis of a prospective, multicentre study involving English-speaking Ontario women.
• Inclusion criteria: singleton pregnancy between 8 and 20 weeks gestation.
• Calculated sensitivity, specificity, predictive values, and likelihood ratios for early excess GWG predicting total excess GWG by BMI category.

Main Results:

• Data from 970 women were analyzed; 387 had first-trimester and 754 had second-trimester weights recorded.
• Excess first-trimester GWG showed low sensitivity (65-68%) and moderate specificity (36-48%) for predicting total excess GWG.
• Excess second-trimester GWG demonstrated high sensitivity (92-96%) but low specificity (16-31%) for predicting total excess GWG across normal, overweight, and obese BMI categories.

Conclusions:

• This is the first Canadian study to investigate early excess GWG as a predictor of total excess GWG.
• Excess first-trimester GWG is not a reliable predictor of total excess GWG in this population.
• Excess second-trimester GWG is a sensitive, though not specific, predictor of total excess GWG, irrespective of maternal BMI.