Model and actress Molly Sims is convinced a "fertility shake" helped her experience motherhood for the second time after struggling to conceive a child with husband Scott Stuber.

The former Maxim Sexiest Woman in the World regular fell pregnant with her first child, Brooks, on her honeymoon in September, 2011, but conceiving again proved difficult until Sims turned to her doula for a little advice - and she turned her on to a nutritional drink that helps prepare the body for pregnancy.

Sims tells U.S. news show Access Hollywood Live, "It's kind of like getting your car geared up with gas and oil; it's called a fertility smoothie and it's nutrient-rich, it's tons of vitamins and it's getting your womb healthy."

The shake features organic mixed berries, bee pollen, rice milk, protein powder and wheatgrass, and Sims insists it has helped her get pregnant again.

She also claims it's great for dads, adding, "It's good for the libido... I made my husband drink it."

The recipe for her fertility smoothie and other pregnancy and pre-pregnancy tips feature in Sims' new book, The Everyday Supermodel.

Her second child is due in March (15).