I did a little research on the two medications and have some concern with the Levothyroxine but the Lisinopril should be okay. Any medication can have an impact on sperm production and fertility. If your wife does not get pregnant within 6 months get a semen analysis to check sperm production and quality levels. The analysis is a quick, easy test that will provide a lot of information. You can get this check now for a piece of mind. Your wife's Ob/Gyn can order this test for you or you primary care physician.
With the thyroid medications my main concern is that the system in the body that regulates the thyroid is also regulating the hormones needed for fertility and sperm productions. If the thyroid is not functioning correctly this impacts those other hormones as well.
Here's what I found:
Levothyroxine - Reproductive: menstrual irregularities, impaired fertility.
There were no adverse effects on reproductive performance in male and female rats treated with up to 300 mg/kg/day of Lisinopril. This dose is 188 times and 30 times the maximum human dose when based on mg/kg and mg/m2, respectively.
Amy Perkins, MS, TS
Laboratory Supervisor
Arizona Andrology Laboratory & Cryobank
International Center for Vasectomy Reversal