【名词&注释】
体外受精(in vitro fertilization)、缺铁性贫血(iron deficiency anemia)、习惯性流产(habitual abortion)、同源人工授精(artificial insemination by husband)、异源人工授精(artificial insemination by donor)、无性生殖(asexual reproduction)
[单选题]产后子宫恢复至非孕期大小约需
A. 3周
B. 4周
C. 5周
D. 6周
E. 7周