It's possible to google the answers to these things, and we're getting off topic. Here's something I found that may answer your question:
https://www.theguardian.com/world/2014/jun/19/us-depleted-ur...
https://www.theguardian.com/world/2014/jun/19/us-depleted-ur...
If you want to labour the point, here's the specific law: https://ihl-databases.icrc.org/customary-ihl/eng/docs/v1_rul...
I'd consider birth defects to be "unnecessary suffering" (this exact wording was used in the Guardian article).
The topic is elaborated on here: Here's an additional link: http://www.austlii.edu.au/au/journals/VicULawJJl/2015/6.html
Thanks for your time. Enjoy the rest of your day.
Ultimately the question is not of great importance because no one actually enforces international law.
Have a nice day :) (said sincerely, without irony)