You've been pregant once though-has his azoospermia improved at all?

Zinc may help, but its place is more in the seminal fluid. Which I presume he still produces.

Tongkat Ali, Longjack (Eurycoma longifolia-Simaroubaceae) has been shown to actually get the body to produce "free swimmers".

Dodder seed, Tu Si Zi (Cuscuta chinensis/japonica-Cuscutaceae) {I recommend in combination with Epimedium sp.}

Monnier's Snowparsley seed, She Chuang Zi (Cnidium monnieri-Apiaceae)

Maca root (Lepidium meyenii/peruvianum-Brassicaceae)

Arctic Rose root (Rhodiola rosea-Crassulaceae)

Puncture Vine (Tribulus terrestris-Zygophyllaceae)

Cnidium, Cuscuta, and Longjack all are known to increase production of the "free swimmers". The others are a definite boost along these lines. Something to do with replacing the "Bound" Testosterone with "Free" Test. & the "Nitric Oxide Reuptake" pathway in the body. On this note 4-Androstenedione (4AD) may be of help as well.

A change of diet according to " Blood Type Diet ", and increasing the antioxidants in the body (such as Bioflavonoids and Superoxide Dismutase-SOD) is also in order.