The aim of this prospective randomized study is the prevention of excessive weight gain in obese pregnant women. The study will compare perinatal outcomes of obese pregnant women treated in the traditional way to outcomes of nutritionally monitored obese pregnant women and evaluate a preliminary behavioral model applicable to the general practice of obstetrics.

Study Population and Selection:

This study will recruit 200 obese pregnant women at 12 to 28 weeks of gestation with a body mass index (BMI) of greater than 29.9 kg/m2. Women will be eligible if they are pregnant with a single fetus, and are free of diabetes, hypertension, or chronic kidney disease at recruitment.

Methodology:

The patients will be randomized to either traditional or monitored groups. All participants will be counseled at least once regarding conventional prenatal nutrition guidelines. A more detailed dietary intake protocol would be done with the intervention (monitored) group, which would include being placed on a balanced nutritional intake regimen of 18-24 kcal/kg/day (no less than 2000 calories). Each patient will be asked to record in a diary all of the foods she eats during the day, which will be reviewed by the investigator or assignee at each prenatal visit. The patients will be weighed at each prenatal visit with the monitored patients weighed and blinded to their actual weight.

Data analysis:

The two groups will be compared with respect to pregnancy weight gain, proportion of excessive weight gain (greater than 15 pounds), maternal morbidity, intrapartum complications and newborn birthweight. The primary analysis will consist of a two sample t-test comparing the monitored versus non-monitored groups with regard to weight gain at delivery. A secondary analysis using a repeated measures ANOVA will look at weight gain in the two groups from baseline to 6 weeks post partum in order to look at trends over time. Tests of mean contrasts will compare differences between the two groups at each time during and post pregnancy relative to baseline. Additional analyses will be done to look at other outcomes. In the case of continuous variable outcomes (e.g., gestational weight), a student's t-test will be used. while for categorical outcomes (e.g., macrosomia), the chi square test will be used for the comparison. Alpha will be 0.05 for each comparison.

Inclusion Criteria:

• BMI greater than 29.9 kg/m2
• Single fetus

Exclusion Criteria:

• Diabetes
• Hypertension or chronic kidney disease