It is not recommended to use metronidazole intravaginally during pregnancy, especially in the first 3 months of pregnancy, as it may be absorbed through the placenta and subsequently affect the fetus. Usually, after the third month of pregnancy, when the fetus is basically developed, if the trichomoniasis is more serious, metronidazole suppositories can be inserted into the vagina. It is important not to use this medication for a long time to avoid prolonged and excessive doses, which can have a great impact on the fetus. In addition, if trichomoniasis is serious and is not treated in time, it can also affect the growth and development of the fetus and even lead to premature rupture of the membranes, resulting in premature birth.