Assisted reproductive technology not tied to higher BMI in childhood, finds study

Being born after assisted reproductive technology (ART) is not associated with higher body mass index (BMI) at age 5 to 8 years, according to a study published online Dec. 19 in PLOS Medicine.

Kristina Laugesen, M.D., Ph.D., from Aarhus University in Denmark, and colleagues examined associations between different fertility treatments and BMI in children at age 5 to 8 years. The analysis included 327,301 Danish children born between 2007 and 2012 (13,675 born after ART and 7,728 born after ovulation induction with or without intrauterine insemination [OI/IUI]).

The researchers found that the crude prevalence of obesity was 1.9% in children born after ART, 2.0% in those born after OI/IUI, and 2.7% in those born after no fertility treatment. Children born after ART and OI/IUI had the same prevalence of being overweight (11%; prevalence odds ratio [POR], 1.00 [95% confidence interval (CI), 0.91 to 1.11]; P = 0.95) or obese (1.9%; POR, 1.01 [95% CI, 0.79 to 1.29]; P = 0.94) in adjusted analyses.

A similar pattern was seen when comparing intracytoplasmic sperm injection with conventional in vitro fertilization (overweight: POR, 0.95 [95% CI, 0.83 to 1.07]; P = 0.39; obesity: POR, 1.16 [95% CI, 0.84 to 1.61]; P = 0.36). After frozen-thawed (2.7%) embryo transfer, obesity was more prevalent than after fresh embryo transfer (1.8%; POR, 1.54 [95% CI, 1.09 to 2.17]; P = 0.01).

"Our overall null results provide reassuring results for couples with infertility seeking help," the authors write.