Based on available data and the potential impact of unhealthy weight gain on maternal and infant health, the Family Health Division has prioritized the need for pregnant women and women of childbearing age to achieve and maintain a healthy body weight. [...] We need to determine optimal weight gain during pregnancy in order to interpret local data on gestational weight gain and describe the magnitude of the problem in Peel. [...] The critical appraisal revealed that the editorial independence of the guideline developers is not discussed and a schedule for updating the guideline is not provided. [...] Recommended ranges were formulated based on the gestational weight Note: Only recommendations gain values associated with the lowest prevalence of the most significant that answered the focused maternal and infant outcomes of weight gain in pregnancy based on practice question were findings from the review of evidence. [...] For each category of pre-pregnancy BMI, the guideline development committee considered: o Incidence or prevalence of each of the key outcomes o Whether the outcomes were permanent or potentially modifiable o The quality of available data o Risk analysis o Acceptability by clinicians and clients Recommended weight gain for singleton pregnancies: Total and rate of weight gain during pregnancy, by pr