in vitro fertilization

例句：

1. 1. This techniqueis used to treat infertilityin couples.
   这种方法用于治疗夫妇的不孕症。
2. 2.The success rate of IVF has improvedsignificantly over the years.
   试管婴儿的成功率在这些年里显著提高。
3. 3. The couple decided to tryIVF after several unsuccessful attemptsat natural conception.
   这对夫妇在自然受孕多次失败后决定尝试体外受精。