When Peter Goldin, a 44-year-old communications director, and his husband decided to start a family through in vitro fertilization, they faced mounds of paperwork at the fertility clinic.

What should happen to any remaining embryos if one partner dies or becomes mentally incapacitated? Who would decide whether remaining embryos should be donated or destroyed? Who would determine the disposition of remaining embryos in the case of divorce or separation?

The couple, who used one embryo to have a daughter, decided that if they broke up, Mr. Goldin would be the one who decided what to do with their one remaining embryo, since it was created with his sperm and a donor egg.

But Mr. Goldin said that when he and his husband separated last year, his husband no longer wanted him to have sole authority to determine what would happen to the embryo.

“He had forgotten what he had signed at the clinic,” said Mr. Goldin, who, with the help of a lawyer, ultimately gained custody after a month of back and forth.

Mr. Goldin, who lives in Richmond, Va., said he would advise couples trying to have a family through I.V.F. to draw up a legal contract detailing each partner’s rights rather than to rely solely on the fertility clinic forms.

Read More.