My wife is pregnant through iui. we had unexplained infertility. if we decide for 2nd child, do you think we'd be able to get pregnant naturally?

Pregnancy: I suggest that when you're ready to try naturally. Since your infertility is unexplained it is unclear why the IUI worked.

Probably not: Generally, if you needed assistance getting pregnant with the first pregnancy, you probably will need assistance again with the second. Although, couples "get lucky" all the time, you should not count on that; and when you are ready for the second child, consider repeating what worked for you the first time. Hope this helps. Good luck.

Difficult to answer: With unexplained infertility it is difficult to say what might assist you in getting pregnant in the future. There is certainly no harm in trying on your own: sometimes things change and pregnancy will happen without assistance. But i would encourage you to get some help soon if she does not get pregnant quickly - within a few months.