Placenta previa: risk factors, maternal and perinatal outcomes

Abstract

Introduction. Placenta previa (PP), especially invasive forms (placenta accreta spectrum PAS), is one of the leading causes of maternal and perinatal morbidity and mortality. The aim of the study is to study the features of the anamnesis, pregnancy and childbirth outcomes for the mother and fetus with placenta previa, and to identify the main risk factors for this pathology. Materials and methods. Retrospective cohort study by continuous sampling method: Group 1 – 64 patients with PP, 2 – 30 women with normal childbirth. The anamnesis of women and pregnancy outcomes were studied. Statistical calculations: Mann-Whitney criteria, χ2 Pearson, odds ratio indicator (OSH). Results. The probability of PP increases in a woman's history with cesarean section in anamnesis (OR 20.53 (7.2–58.53), p < 0.001), premature birth (OR 4.29 (1.45–12.68), p = 0.04), abortion (OR 3.77 (2.32– 6.12), p = 0.004), including induced (OR 14.16 (4.95–40.53), p = 0.001) and spontaneous (OR 3.65 (2.01–6.62), p = 0.02), as well as somatic diseases (OR 6.17 (3.8–10.02), p < 0.001), especially the presence of anemia (OR 19.84 (6.95–56.61), p < 0.001), gastrointestinal diseases (OR 13.18 (4.6–37.75), p = 0.002), overweight/obesity (OR 6.23 (2.14–18.14), p = 0.015), varicose veins (OR 5.37 (1.84–15.72), p = 0.005). The threat of miscarriage (p = 0.012), placental disorders (p = 0.012), anemia (p = 0.026), genital infection (p = 0.023) were recorded more often in women with placenta previa. All women with PP were delivered by operation caesarean section, often prematurely (45.3 %; p < 0.001), urgently (45.3 %, p < 0.001) because of bleeding (37.5 %, p < 0.001). The expansion of the volume of surgery was required in 37.5 % of cases, hemotransfusion – 50.0 %. Morphofunctional indicators of children from mothers with PP were significantly lower, and the frequency of asphyxia, respiratory distress syndrome, аrtificial lung ventilation was higher than in the control group. Discussion. PP and PASS are potentially dangerous pathologies for the life and health of women and children, which is confirmed by the results of this study. However, problems of diagnosis of this pathology were revealed at the outpatient stage. In addition to the well-known risk factors for abnormal placentation, associations of PP with a low socio-economic status of a woman and a number of somatic nosologies, such as obesity, anemia, gastrointestinal tract diseases, varicose veins, the influence of which is probably indirect. The association of abnormal placentation with excessive use of gestogens during pregnancy cannot be ruled out. Conclusions. The risk factors for PP were the presence of a history of cesarean section, abortions, premature birth, low socio-economic status, somatic pathology (overweight / obesity, anemia, gastrointestinal diseases, varicose veins). PP is associated with a high frequency of the threat of miscarriage, placental disorders, genital infection, premature birth, cesarean section operations, bleeding, decreased morphofunctional indicators of newborns, perinatal morbidity and mortality