There is not enough evidence to recommend any intervention for preventing excessive weight gain during pregnancy, due to the significant methodological limitations of included studies and the small observed effect sizes. More high-quality randomised controlled trials with adequate sample sizes are required to evaluate the effectiveness of potential interventions.
Perinatal outcomes in nutritionally monitored obese pregnant women: a randomized clinical trial.
Although obesity in pregnancy continues to be associated with ongoing health problems, many clinicians have been reluctant to place nondiabetic, obese, pregnant women on a monitored, calorie-appropriate nutritional regimen for fear of fetal growth restriction, low birth weight, or starvation ketosis.
                A total of 257 patients were enrolled in the randomized study, with a loss-to-follow-up rate of 9.73%. Patients were assigned randomly to either the control (unmonitored) group (n=116), consisting of conventional prenatal dietary management, or to the study (monitored) group (n=116), which was prescribed a balanced nutritional regimen and were asked to record in a diary all of the foods eaten during each day. Women were eligible for the study if they were pregnant with a single fetus between 12 and 28 weeks of gestation and had a prepregnancy body mass index of more than 30 kg/m2. The primary outcome was to compare perinatal outcomes in the control vs the study groups. The secondary measure was to compare outcomes in adherent and nonadherent patients in the study group.
                Omnibus MANOVA showed statistically significant differences between the study and control groups regarding 3 variables: (1) gestational hypertension, p < .46; (2) mother's last weight before delivery, p < .001; and (3) mother's 6-week postpartum weight, p < .001. Patients gaining 15 pounds or more during their pregnancy showed statistically significant differences between the groups for 8 variables.
                Obese pregnant women may be placed on a healthy, well-balanced, monitored nutritional program during their antepartum course without adverse perinatal outcomes.