US couple 'called to adopt' embryos
Instead of using donated sperm or eggs, couples who struggle to conceive a child also have the option of using donated embryos.
In the US this is commonly referred to as "embryo adoption", particularly at Christian clinics, where recipients and doctors view it as saving a life.
Jennifer and Aaron Wilson, from North Carolina, say their Christian faith and belief that life begins at fertilisation led them to use other people's embryos rather than start IVF themselves.
They travelled to the National Embryo Donation Center in Tennessee to have three clusters of cells implanted.
Filmed and edited by Peter Murtaugh and Olivia Lace-Evans. Produced by Jasmine Taylor-Coleman