B.J. Holt always wanted to be a dad. As he approached 40, with no life partner in sight, he felt a version of the ticking biological clock. "The 'having the children thing' started to overwhelm the desire to have the relationship first," Holt says. "They sort of switched on me." So Holt decided to go it alone. A few years ago, he used an egg donor and a surrogate to create a family of his own.