I am seeing several comments here that are, in my experience, misperceptions about pregnant womens' insurability.
Here's what I wrote in a recent post addressing this issue:
Old post, but I applied for a policy and had the physical shortly before learning I was pregnant. I'd heard the same as you and so was planning to get the policy finalized before getting pregnant, and was surprised when it happened so quickly (lots of friends with fertility problems led to its own kind of recency bias ) The life insurance company returned an underwritten policy, but I had to disclose my pregnancy in response to the update questions about recent doctor visits or medical developments. They insurance company then had some questions for me -- IIRC they wanted to know whether we'd used any ART or whether it was an "old fashioned" pregnancy, and whether I'd had any adverse pregnancy-related conditions like gestational diabetes or hypertension. But since it was a normal healthy pregnancy to that point, they ended up sticking to the same premium.
So yes, I think it is better to get it done before you get pregnant, because it is impossible to know who will end up with conditions like GD or hypertension, etc., but if you have a healthy pregnancy it's not necessarily going to affect your premiums. I did have to lean on them to re-review my file quickly so I didn't age up before the start date of the policy and have to go through underwriting AGAIN...
This was with Banner, fwiw.
So on the one hand, I don't think Meg77 gives sound advice when she suggests waiting to apply until your wife is 4-6 months along. For one thing, it can take longer to get a pregnant woman's application through underwriting, and you want the policy in force at the very latest by the date of your child's birth, in the event your wife dies in or just after labor. For another thing, depending on whether you and your wife conceive naturally or with medical assistance, or whether your wife suffers an ectopic pregnancy, gestational diabetes, preeclampsia, or other pregnancy-related condition (many of which are difficult to impossible to predict for a given woman before she gets pregnant), her rates could go up. So getting the policy before she gets pregnant guards against any of those possibilities -- either delays in getting the policy in force or premium increases due to pregnancy-related medical risks. Or, for that matter, any potential legal dispute with the carrier over whether you did or did not disclose all relevant information at the time your applied and executed the policy.
On the other hand, pregnant women are NOT uninsurable. Some carriers may give pregnant women crap rates, but if you shop around I think you will find that's easily avoided. So if your wife does get pregnant before she applies, or gets pregnant while her policy is going through underwriting, it may not affect her insurability or her rate at all, provided she is otherwise low risk.
Better safe than sorry, though, IMO. I suggest applying for coverage a few months before you intend to start trying. Less hassle and less risk if you get the coverage in place before she is pregnant. If she is otherwise healthy, the premium will be low enough that it won't matter in the scheme of things if you take a while to conceive. (Not to mention, if it takes a while for you to conceive, that could be related to other factors that will cause her rates to jump.)
For what it's worth, my husband and I got a 20year trm policy when we married to cover the mortgage plus a small amount of lost income, and a few years later when we started planning for our family, we took out about 10y income for each of us on a 30y term policy. The 20y policy will carry us through our baby's high school graduation, by which point we plan to have the mortgage paid off, and the 30y policy will cover family expenses through college. Given our other assets and our respective careers (earnings and stability) we were comfortable not covering more years of income. We both have additional coverage through our employer, which we treated as a cushion for any near-term losses but totally disregarded when looking at what we'd need a few years down the road -- since who knows what covereage we'll have through what job at that point.
Good luck on the insurance and on the eventual baby!