Aim. To evaluate the prevalence of preterm birth and risk factors for extremely preterm, very preterm, and moderate to late preterm birth.Materials and Methods. We retrospectively assessed case histories of 11,500 pregnant women delivered in Kuzbass Regional Children's Clinical Hospital during 2019-2021 and their newborns. Among the studied factors were gestational age, birth weight, sex, 5-minute Apgar score, maternal age (< 20 years, 20-35 years, ≥ 35 years), parity (primiparity or multiparity), active smoking, maternal diseases during pregnancy (gestational hypertension, intrahepatic cholestasis of pregnancy, gestational diabetes mellitus, anemia, gastrointestinal and genitourinary diseases), chorioamnionitis, and pregnancy complications (placental abruption, placenta previa, vaginal bleeding, polyhydramnios), fetal distress, and fetal growth restriction.Results. Prevalence of preterm birth was 8.4%. The potential risk factors for preterm birth were placental abruption, placenta previa, short (< 25 mm) cervix, intrahepatic cholestasis of pregnancy, gestational hypertension, chorioamnionitis, anemia, young (< 20 years) and advanced (≥ 35 years) maternal age, primiparity, active smoking, and fetal distress. Among them, placental abruption, placenta previa, short (< 25 mm) cervix, gestational hypertension, and chorioamnionitis were specific risk factors of extremely preterm and very preterm birth whilst intrahepatic cholestasis of pregnancy was the risk factor of moderate to late preterm birth.Conclusion. Extremely preterm, very preterm, and moderate to late preterm birth have distinct risk factor profiles, highlighting the need for differential pregnancy management strategies.

Annually, about 15 million of infants are born prematurely, and preterm birth is associated with an increased risk of neonatal morbidity and mortality. Further, the risk of repeated premature birth is relatively high, as 25% of pregnancies following those interrupted at 23-28 weeks of gestation also result in a preterm birth within the similar time frame. Among the major risk factors of preterm birth is cervical insufficiency, and cervical length measurement is recommended for all pregnant women at 18−21 weeks of gestation. For patients at high risk of late miscarriage and preterm birth, cervical length measurement should be performed weekly from 15 to 24 weeks of gestation. The use of pessary, which reduces amniotic sac pressure on the internal os, has been suggested as an appropriate option to correct cervical insufficiency as it does not require surgery, has low risk of complications and is easy to use. Relevant papers published hitherto report contradictory results, which require further research.

Aim. To determine the level of estradiol, progesterone, IgA and IgG to these hormones, and IgA/IgG to benzo[a]pyrene in women with cervical weakness.Materials and Methods. We retrospectively analysed case histories of 200 women, including 100 patients with cervical weakness defned by an ultrasound examination at 18-21 weeks of gestation and 100 patients without cervical weakness. Serum estradiol, progesterone, IgA and IgG to these hormones, and IgA/IgG to benzo[a]pyrene were measured at 18-21 weeks of gestation using enzyme-linked immunosorbent assay.Results. Patients with cervical weakness had a higher level of serum estradiol [12477 (1000; 31600) pg/mL], IgA to progesterone [2.15 (0.6; 8.3) a.u.] and benzo[a]pyrene [4.74 (0.4; 13.9) a.u.], IgG to estradiol [8.64 (1.2; 23.5) a.u.], progesterone [5.29 (0.2; 20.1) a.u.], and benzo[a] pyrene [11.89 (1.1; 28.5) a.u.] as compared with those without [10946 (2999; 19480) pg/mL, p = 0.034]; [1.42 (0.6; 2.6) a.u., p = 0.034]; [3.22 (0.7; 5.7) a.u., p = 0.032]; [4.78 (0.7; 8.7) a.u., p < 0.0001]; [2.55 (0.2; 5.1) a.u., p < 0.0001]; [4.72 (0.4; 10.1) a.u., p < 0.0001]. An association between the preterm birth and levels of IgA to progesterone (p = 0.00017) and benzo[a]pyrene (p = 0.0003) was established.Conclusion. Patients with cervical weakness were characterized by higher levels of IgA and IgG to estradiol, progesterone, and benzo[a]pyrene; notably, increased IgA to progesterone and benzo[a] pyrene correlated with a higher risk of preterm birth.