Abstract: Pregnancy is a time of dramatic immune and physiological changes that serve to accommodate the growing fetus. During pregnancy, alterations in the gut and vaginal microbiome populations occur. These alterations might influence the maternal metabolic profile and contribute to the mebabolic and immunological health of the offspring. Recently, the role of gut microbiome in pregnancy has become the subject of considerable interest. It has been reported that the maternal microbiota from the third trimester of normal pregnancy show signs of gain weight and insulin insensitivity similar to those observed in obesity.Lately, the vaginal microbiota of pregnant women become more and more important. The lactobacillus is also dominant in vagina in conception, but the correlation of vaginal microbiota and pregnancy outcome still need investigate furtherly. Further, it has recently become clear that the placenta has a microbiome. The placental microbiome is associated with preterm birth, indicating that the crosstalk between bacterial communities and the pregnant women may be of great importance.

Key words: Pregnancy, Intestines; , Vagina, Placenta, Microbiome, Weight gain, Insulin resistance