Pregnancy may serve as a unique window for lifestyle behavioral change because of increased concern for health and well-being in expectant mothers. PURPOSE: To report the recruitment efforts and results undertaken in a behavioral lifestyle intervention administered during and after pregnancy. METHODS: The Health in Pregnancy and Postpartum (HIPP) Study is an ongoing randomized controlled trial that targets excessive weight gain during pregnancy and promotes weight loss after delivery. The target population includes overweight or obese women who are pregnant ≤ 16 weeks, white or African American, aged 18-44 years, and do not have exercise contraindications. Women are recruited through OB/GYN clinics in metropolitan Columbia, SC. Interested women who meet the initial inclusion criteria (i.e., age, race, gestational age, and pre-pregnancy BMI) are screened by phone for medical exclusions or other study exclusions. A script based on principles of motivational interviewing is used to ensure women consider pros and cons of each study condition, and if still interested in participating, they are scheduled for baseline visit. RESULTS: Of the 1,547 women initially eligible and interested, only 822 (53.1%) could be reached by phone for further screening and 161 (19.6%) were found ineligible. Of the 661 eligible women screened by phone, 387 (58.5%) scheduled baseline measurements. Top reasons women were ineligible include: incompetent cervix (3.3%), insulin-dependent diabetes (3.0%), and doctor contraindicated exercise during pregnancy (2.7%). After accounting for cancelled or no show (n=126) and in progress (n=4) appointments, 257 (66.2%) women have completed the in-person portion of baseline measurements, resulting in the overall recruitment yield of 16.6% (257/1547). Women who cancelled or did not show up at baseline visits were less likely to have their own cell phone (p=0.02) or a smart phone (p<.004), receive <20 texts/day (p<.0001), have access to a computer (p=.007), or have ever downloaded a podcast (p=.0008); women were more likely to miss or cancel appointments in April, July, and December (p<.0001). CONCLUSION: Recruitment of women in early pregnancy for a behavioral lifestyle intervention appears challenging, particularly among women with limited phone access.