Safety and efficacy of a lifestyle intervention for pregnant women to prevent excessive maternal weight gain: a cluster-randomized controlled trial

Background: Excessive gestational weight gain (GWG) is associated
with short- and long-term health problems among mothers and their
offspring. There is a strong need for effective intervention
strategies targeting excessive GWG to prevent adverse outcomes.
Methods: We performed a cluster-randomized controlled intervention
trial in eight gynecological practices evaluating the feasibility
and effectiveness of a lifestyle intervention presented to all
pregnant women; 250 healthy, pregnant women were recruited for the
study. The intervention program consisted of two individually
delivered counseling sessions focusing on diet, physical activity,
and weight monitoring. The primary outcome was the proportion of
pregnant women exceeding weight gain recommendations of the
Institute of Medicine (IOM). Secondary outcome variables were
maternal weight retention and short-term obstetric and neonatal
outcomes. Results: The intervention resulted in a lower proportion
of women exceeding IOM guidelines among women in the intervention
group (38\%) compared with the control group (60\%) (odds ratio
(OR): 0.5; 95\% confidence interval (CI): 0.3 to 0.9) without
prompting an increase in the proportion of pregnancies with
suboptimal weight gain (19\% vs. 21\%). Participants in the
intervention group gained significantly less weight than those in
the control group. Only 17\% of the women in the intervention group
showed substantial weight retention of more than 5 kg compared with
31\% of those in the control group at month four postpartum (pp)
(OR: 0.5; 95\% CI: 0.2 to 0.9). There were no significant
differences in obstetric and neonatal outcomes. Conclusions:
Lifestyle counseling given to pregnant women reduced the proportion
of pregnancies with excessive GWG without increasing suboptimal
weight gain, and may exert favorable effects on pp weight
retention.