London, May 20 : British musician Rod Stewart and his wife Penny Lancaster are desperate to have a second child, but fear they have very less time left to conceive, as their biological clock is ticking.
Rod and Lancaster, who have three-year-old son Alastair together, have been trying for a baby for more than a year.
"I think Rod''s touring and running around interferes with things but we still have high hopes," the Daily Star quoted Lancaster as saying.
"It''s simply a question of age. It does become more difficult the older people are," she added.
Rod has five children-Kimberly, Sean, Ruby, Renee and Liam-from previous relationships.