Sierra Poulson at her home in Omaha, Neb. Ms. Poulson, who has donated her eggs three times, helped start an online forum for egg donors. Credit Ryan Henriksen for The New York Times

Sierra Poulson at her home in Omaha, Neb. Ms. Poulson, who has donated her eggs three times, helped start an online forum for egg donors. Credit Ryan Henriksen for The New York Times