act of God vs childbirth

act of God

noun
  • An unforeseen occurrence beyond one's control, such as a natural disaster. 

  • Used other than figuratively or idiomatically: see act, of, God. 

childbirth

noun
  • The fact or action of giving birth to a child, as the culmination of pregnancy. 

How often have the words act of God and childbirth occurred in a corpus of books? (source: Google Ngram Viewer )