For surrogate pregnancies in which just one boy or girl is born, the preterm birth fee in surrogacy is marginally lessen than toddlers born from normal IVF (11.5% vs 14%). Infants born from surrogacy even have similar common gestational age as infants born by in vitro fertilization and oocyte donation; https://digitalasset.b-cdn.net/SouthernCaliforniaSurrogacy/Becoming-A-Surrogate-In-Southern-California.html