Abstract: Objective To investigate the effects of exogenous sex hormones supplementation to in vitro fertilization-embryo transfer (IVF-ET)/frozen-thawed embryo transfer (F-ET) patients on serum concentrations of five trace elements as well as estradiol (E2) and progesterone (P) in pregnant women during the first trimester of pregnancy. Methods A total of 863 pregnant women (including 800 in vitro fertilization-embryo transfer (IVF-ET)/frozen-thawed embryo transfer (F-ET) patients and 63 nature pregnancy) were studied, the IVF-ET/F-ET patients were divided into 3 groups according to their different embryo transfer cycle. Serum samples were collected in the morning of their 6-8 weeks of pregnancy and the serum concentrations of copper, zinc, calcium, magnesium, iron, estradiol and progesterone were measured. Results The serum E2 and P levels rose with the increase of hormone intake due to different IVF-ET cycles. The copper levels in four groups were significantly different (all P<0.05), the lowest in the natural pregnancy group and highest in the fresh cycle group. The copper level was positively correlated with the estradiol level (r=0.08,P=0.024). The levels of serum magnesium and iron in multiple pregnancies were lower than those in singleton pregnancies (all P<0.05). Conclusions Serum copper level of pregnant women who received IVF-ET/F-ET treatment is higher than that of women with natural pregnancy, and it has positive correlation with serum E2 level. The demands of magnesium and iron of multiple pregnancy are higher than those required by singleton pregnancy.