Researchers at Vanderbilt University have published research that may implicate cannabis in the aetiology of ectopic pregnancy.
Sue Jacob's comments are featured:
Sue Jacob from the Royal College of Midwives said: "We need to look at the bigger picture.
"The rise in sexually transmitted infections, the rise in alcohol binging and the rise in drug taking all have an impact on sexual health. Ectopic pregnancies need to be researched further in light of these behaviours," she said.