Preterm placental abruption. Epidemiology, risk factors. Systematic review

Abstract

Preterm placental abruption is a multifactorial pregnancy complication, the etiology of which remains uncertain, and the risk of maternal morbidity and perinatal mortality is high. Over the past decade, the profile of obstetric patients has changed, as well as the approaches to medical care, and some risk factors for preterm placental abruption have also been revised. Objective. To summarize current knowledge about the epidemiology and causes of preterm placental abruption. Materials and methods. The search for publications was carried out in the electronic databases PubMed, Web of Science, SCOPUS, Google Scholar by four reviewers independently from January 1, 2017 to March 31, 2020. Clinical case reports, conference abstracts and studies with no comparison group were excluded. Results. Thirty-four studies involving 20,833,192 patients met the inclusion criteria, of whom 193,114 were diagnosed with preterm placental abruption, with an incidence of 0.93% (after excluding five studies with cross-sectional design, the overall incidence of preterm placental abruption decreased to 0.83%). According to the results obtained, among the undoubted risk factors for preterm placental abruption were smoking (odds ratio (OR) 1.72–13.0), anemia (OR 1.36–2.44), chronic kidney disease (OR 3.72– 5.51), the Negroid race (OR 1.47–3.59), uterine scar (OR 1.53–6.33) and uterine anomalies (OR 3.35–4.69). Contradictory information was received about the negative impact of the following factors: maternal age, assisted reproductive technologies, gynecological diseases, alcohol, various air pollutants and hot weather. Obesity was among the risk factors that did not affect preterm placental abruption (OR 0.81–0.74). Conclusion. The risk factors presented in the review were divided into groups. In the first two, timely correction of lifestyle and/or prescription of medicines can reduce the probability of preterm placental abruption. The third group is represented by risk factors, most of which are beyond regulation. However, to fully understand the etiology of preterm placental abruption, further qualitative studies with their more frequent systematization are required. Key words: pregnancy, ischemic placental disease, preterm placental abruption, risk factors, epidemiology