例句 /

Since 1990, 2 randomized trials and several observational studies have evaluated the benefits vs risks of expectant management of severe preeclampsia at <34 weeks of gestation.

Since 1990, 2 randomized trials and several observational studies have evaluated the benefits vs risks of expectant management of severe preeclampsia at <34 weeks of gestation.

自1990年以来,2个随机试验和一些观察性研究评价了对于妊娠小于34周的重度先兆子痫采用保守治疗的利与弊。