A Pilot Randomized Controlled Trial of a Partial Meal Replacement Preconception Weight Loss Program for Women with Overweight and Obesity.

About half of Australian women have a body mass index in the overweight or obese range at the start of pregnancy, with serious consequences including preterm birth, gestational hypertension and diabetes, caesarean section, stillbirth, and childhood obesity. Trials to limit weight gain during pregnancy have had limited success and reducing weight before pregnancy has greater potential to improve outcomes. The PreBabe Pilot study was a randomised controlled pilot trial to assess the feasibility, acceptability and potential weight loss achieved using a commercial online partial meal replacement program, (MR) vs. telephone-based conventional dietary advice, (DA) for pre-conception weight-loss over a 10-week period. Women 18-40 years of age with a BMI ≥ 25 kg/m planning pregnancy within the next 6 to 12 months were included in the study. All participants had three clinic visits with a dietitian and one obstetric consultation. In total, 50 women were enrolled in the study between June 2018 and October 2019-26 in MR and 24 in DA. Study retention at the end of 10 week intervention 81% in the MR arm and 75% in the DA arm. In the-intention-to-treat analysis, women using meal replacements lost on average 5.4 ± 3.1% body weight compared to 2.3 ± 4.2% for women receiving conventional advice ( = 0.029). Over 80% of women in the MR arm rated the support received as excellent, compared to 39% in the DA arm ( < 0.001). Women assigned to the MR intervention were more likely to achieve pregnancy within 12 months of the 10 week intervention (57% (12 of 21) women assigned to MR intervention vs. 22% (4 of 18) assigned to the DA group ( = 0.049) became pregnant). The findings suggest that a weight loss intervention using meal replacements in the preconception period was acceptable and may result in greater weight loss than conventional dietary advice alone.