One study, published in 2001 in the journal Human Fetal and Neonatal Movement Patterns, found that boys may move around more in the womb than girls. That study found that the average number of leg movements was much higher in the boys than the girls at 20, 34, and 37 weeks. But the study's sample size was small, only 37 babies, so Nowlan and her colleagues are hesitant to claim there's a relationship between gender and fetal movement.