Associations among gestational weight gain, physical activity, and pre-pregnancy body size with varying estimates of pre-pregnancy weight.

OBJECTIVES

the purpose of this study was to examine associations among gestational weight gain (GWG) and pregnancy leisure-time physical activity (LTPA), within pre-pregnancy body mass index (BMI) categories, while utilising two different estimates of pre-pregnancy weight.

DESIGN

a cohort study. Data were collected via questionnaire and abstraction from birth certificate as a part of a larger study.

SETTING

three antenatal clinics in Lansing, Michigan, USA.

PARTICIPANTS

a subset of women who participated in the Archive for Research on Child Health (ARCH) study and delivered a singleton, term infant (n=135). Participants were enroled prior to 14 weeks׳ gestation.

MEASUREMENTS

pre-pregnancy BMI was categorised as normal, overweight and obese (excluded underweight). GWG was calculated by subtracting pre-pregnancy weight from weight at childbirth (obtained from birth certificate) and classified as 'excess' or 'not excess' using the upper limit of the 2009 IOM recommended range. These two variables were constructed twice, first by using pre-pregnancy weight self-reported at enrolment and second, by using pre-pregnancy weight recorded on birth certificates. LTPA, also self-reported at enrolment, was modelled using two thresholds, moderate LTPA, and vigorous LPTA.

FINDINGS

overall, 56-60% of our sample experienced excess GWG, depending on the source used for pre-pregnancy weight. Overweight and obese women had significantly higher odds of excess GWG (compared to normal weight women; Odds Ratio (OR)=2.48-5.34). LTPA level did not differ among pre-pregnancy BMI categories and was not related to appropriateness of GWG.

KEY CONCLUSIONS

regardless of the source of pre-pregnancy weight, overweight and obese women were more likely to experience excess GWG (compared to normal weight women) and LTPA was not significantly related to the appropriateness of GWG.

IMPLICATIONS FOR PRACTICE

findings highlight the need for practitioners to effectively communicate GWG recommendations and counsel women about the importance of achieving appropriate GWG. Although GWG counselling has traditionally been focused on obese women, these results suggest overweight women are in need of GWG counselling as well.