The objective: to reduce the frequency of the threat of pregnancy interruption and loss in women with uterine fibroid through treatment prediction and improvement.Materials and methods. A complex examination of 70 pregnant women with uterine fibroid at 15-16 weeks of pregnancy (main group) and 50 pregnant women without uterine fibroid at the same gestational term (control group) was carried out at 4 clinical bases of the Department of Obstetrics and Gynecology N1 of the Shupyk National Healthcare University of Ukraine in the time period of 2020-2022. Pregnant women in the main group were divided into 2 subgroups depending on the type of the nodes: Ia – 39 pregnant women with subserous type of fibroid nodes (type 5-6 according to FIGO) and Ib – 31 pregnant women with intramural fibroid (type 3-4 according to FIGO). The pregnant women in the main group received the complex of developed therapy for pregnancy interruption (micronized progesterone, magnesium preparations, vitamin B6, acetylsalicylic acid), in the control one – the common therapy (bed rest, abstinence from sexual life, micronized progesterone preparations, tranexamic acid).The concentrations of estradiol, progesterone, human chorionic gonadotropin (hCG) were determined in the blood plasma of all persons at 15–16 weeks and 24 weeks of pregnancy.Results. In the II trimester the concentration of estradiol in the blood of pregnant women with intramural uterine fibroid, especially with multiple forms, was significantly higher than in the control group (p<0.05). At the same time, in pregnant women with intramural fibroid node(s) the mean concentration of estradiol exceeded the similar indicator in the group with the subserosal type (p<0.05). These changes indicated the stress of the hormonal function of the placenta and were considered by us as one of the signs of the initial stage of placental dysfunction.With an increase in estradiol concentration, a significant decrease in progesterone amount was noted. Progesterone deficiency was significantly more common in the subgroup of pregnant women with multiple intramural uterine fibroid and nodes in contact with the uterine cavity, especially at the place of placenta attachment (type 3) – 165.24±14.71nmol/l compared to the control group – 219.96±16.63 nmol/l, and with pregnant women with subserosal node(s) – 210.61±18.57 nmol/l (р<0.01), which confirms the threat of abortion and indicates the development of placental dysfunction. In the II trimester of pregnancy the concentration of hCG in women with uterine fibroid was significantly lower than in women without uterine fibroid and especially lower in multiple uterine fibroid. In the women of the main group progesterone and hCG concentrations in the blood plasma normalized (p>0.05) after the treatment, but the level of estradiol in the group of pregnant women with multiple intramural uterine leiomyoma remained significantly higher (p<0.05).Conclusions. Pregnant women with uterine fibroid have an increased risk of placental dysfunction with a disbalance of the main placental hormones: an increase in estradiol concentration and a relative decrease in progesterone and human chorionic gonadotropin, a shift in the estrogen-progesterone balance towards relative hyperestrogenia.The use of medical measures with long-term support with progesterone, magnesium and low doses of acetylsalicylic acid for the prevention of miscarriage in persons with the clinical manifestations of the threat of gestation is quite effective.