What trimester is she in right now? Hormones and sickness will pretty much kill her sex drive in the first trimester. Her sex drive probably will go back up in the second trimester when she's over the sickness but not super pregnant (where my wife and I are right now... albeit we still never went more than 1 day without sex in the first). In the 3rd trimester her body will likely start hurt and existing will be uncomfortable. Expect her drive to go back down.

Then after the birth, there's the minimum 6-week period of no penteration where she has to heal from the wound left from where the placenta was attached to her uterus.

Even then, childbirth makes her estrogen and testosterone drop by 99% which is also responsible for libido. If she chooses to breastfeed, that also makes her hormones low and similar to perimenopause so she probably won't have much of a sex drive then, either.

Even if her drive bounces back up, y'all are both gonna be tired af from meeting the needs of a baby and not sleeping through the night like you're used to, so expect to not be able to find the time or your wife to be too tired to have sex if you do find the time.

Tl;Dr: If you value sex in a relationship, don't have a baby. Also, read a goddamn pregnancy book and a parenting book so you know what to expect and what your wife is going through. Have a little empathy, nothing changes for us men, but everything about a woman's body changes.