Has anyone had experience with metformin decreasing sperm count? Up until now DH has had a normal sperm count but was recently diagnosed with type 2 diabetes and is taking metformin. My RE is sending him for another sperm count. Thoughts?

DS 7.6.2011 TTC#2
Re: Metformin affecting sperm count?
IUI#2 Femara/Ovidrel (cd 5-9) = BFN
IUI#3 Femara/Ovidrel (cd 3-7) = BFP!
beta #1 11/23 = 270, P4 = 75
beta #2 11/28 = 2055
Our daughter E was born 7/29/2012!
Surprise, our 2nd daughter P was born 5/22/14!