rate of pregnancy

例句：

1. 1. Thestudy found that the rate of pretermbirths has increased significantly in recent years.
   研究发现，近年来早产儿出生率显著增加。
2. 2. The government is considering raising the legalage for marriage to reduce the rate ofchildbirth.
   政府正在考虑提高法定结婚年龄以降低生育率。
3. 3. Theresearchers analyzed data from variouscountries to determine the rate ofcontraception use among women.
   研究人员分析了来自不同国家的数据显示女性避孕使用率。