Placenta accreta spectrum disorders in the first trimester: a systematic review

Placenta accreta spectrum (PAS) disorders involve an abnormality in the implantation of the placenta, being rarely diagnosed in the first trimester. To conduct a systematic review of the risk factors, clinical and imaging features, and outcomes of histopathologically confirmed cases of PAS disorders in the first trimester of pregnancy. Different databases including PubMed, MEDLINE Complete, Scopus, Web of Science, EMBASE, SciELO, LILACS, and Ovid were reviewed up to November 2018. 55 patients with a definitive histopathological diagnosis were reported. About 18 had a history of prior curettage and 47 of previous caesarean deliveries (CD). About 74.54% presented with miscarriage and ultrasound signs of caesarean scar pregnancy (CSP) were reported in 22.49%. Temporal sequence of diagnostic studies could be determined in 52 women, and, among these, PAS disorders were defined through imaging techniques in 11 (21.15%) while surgical findings unveiled them in 15 (28.84%). Nonetheless, in half of the cases, the diagnosis was concluded only on histopathological samples. PAS disorders in the first trimester of pregnancy are rarely diagnosed through imaging techniques and lead to hysterectomy in most cases. Ultrasound training to detect PAS disorders in women with risk factors is crucial for early diagnosis and prevention of adverse outcomes.

胎盘植入性疾病（Placenta accreta spectrum, PAS）是一类胎盘植入异常的病症，在妊娠早期罕有确诊。本研究旨在针对妊娠早期经组织病理学证实的胎盘植入性疾病病例，对其危险因素、临床及影像学特征与转归开展系统综述。研究检索了截至2018年11月的PubMed、MEDLINE Complete、Scopus、Web of Science、EMBASE、SciELO、LILACS及Ovid等多个数据库，最终纳入55例经明确组织病理学诊断的患者：其中约18例存在既往刮宫史，47例有剖宫产术（caesarean deliveries, CD）史；约74.54%的患者表现为流产，22.49%的病例被检出剖宫产瘢痕妊娠（caesarean scar pregnancy, CSP）的超声征象。52例患者可明确诊断检查的时间顺序，其中11例（21.15%）通过影像学技术确诊胎盘植入性疾病，15例（28.84%）经手术所见明确诊断；但仍有半数病例仅通过组织病理学样本才得以确诊。妊娠早期的胎盘植入性疾病罕有通过影像学技术确诊，且多数病例需行子宫切除术。针对存在危险因素的女性开展胎盘植入性疾病超声筛查培训，对早期诊断及预防不良结局至关重要。