Please tell your friend to be careful and seek advice - yes you can conceive naturally with a balanced translocation but you have a larger risk for having a child with chromosome deletions and big issues. It would be wise to inform yourself about these risks. I'm sorry to mention this.
Simply put, each chromosom has 2 arms and these arms can be swapped (translocate) between chromosomes. When someone with a translocation has children, they can pass the translocation onto their child, or the tranlsocation can result in extra or missing genetic material on one or more of the chromosome arms. These are probably the fetuses with chromosomal problems that are misscarried. Someone with a translocation can have some medical issues themselves, duplications also results in some issues and deletions generally alot more.
My DD has a significant chromosome deletion and she's one of the lucky ones whos mostly ok (short statured, some blood problems at birth), but I read every day in a facebook group for children with unusual chromosome deletions - nearly all of these children have global development delays and a range of health issues. DD's case is actually spontaneous (neither DH nor I have any unusual chromosomes), but many of the cases I know of come from parents with translocaitons.
- this is a non-profit foundation for people with rare chromosome diagnoses . There is lots of excellent information about unusual chromosome issues. They might be able to help you more with actual numbers regarding what the risks are and put you in contact with people with similar diagnoses. I really hope things work out for you..
"The effects of rare chromosomal disorders can be very varied. The vast majority of carriers of balanced rearrangements will have no symptoms but might have problems in reproduction. "