Hi doma,
He said he meant to say forcible.
"The body of a woman who is experiencing real rape shuts down so the chances of conceiving are low,whereas a woman who claims rape as an after thought after intercourse experiences a greater chance of conception."
- this is not actually correct,
http://www.cnn.com/2012/08/20/opinion/carroll-akin-rape/index.html
but it is based on medieval ideas of how conception works.
http://www.guardian.co.uk/science/the-h-word/2012/aug/20/legitimate-rape-medieval-medical-concept