No sir, a pouch kit is not needed for pregnant males. It has no use during a normal pregnancy and does not help the male carry his brood of developing young, deliver them following gestation, or flush out his pouch in preparation for re-mating and his next brood. The pouch kit is not used routinely at all but only when health problems crop up. However, it is a very useful item for seahorse keepers to have on hand for those occasions when cases of bloated pouch or chronic pouch emphysema occur, as described below:
Bloated pouch is the most common ailment of seahorses and every seahorse keeper should have the equipment needed to treat the condition on hand. This includes a small syringe with catheter, suitable eyedropper, pipette or the like for rinsing the pouch, as well as a medicated pouch-flush solution. (The small syringe and catheter are also useful for tube feeding seahorses that are on a hunger strike.) Ready-made kits consisting of special antibiotic solution, flushing apparatus and instructions are available from the Ocean Rider seahorse farm in Hawaii, or you can easily assemble your own kit from the necessary components. Acetazolamide combined with nifurpirinol and neomycin makes a superior pouch wash for cleansing the marsupium and stopping the formation of excess gas.
Best of luck with your new seahorses, Nigel! Here’s hoping you never have need for a pouch kit!