If you know you will have a large medical expense, you should probably expect to pay the out of pocket maximum, not the deductible. In general, you'll be comparing your share of the monthly premium x 12 + out of pocket max and pick the cheaper. The thread quoted before goes into more detail.
That said, the insurance world is changing a lot. Unless your employer offers full coverage to both you and your spouse (guessing it's your wife that will be having the baby based on your name), does not offer a kickback if you take the cheaper insurance, and your spouse has no offer of employer coverage, you will want to look at all of your options and all possible configurations because generally, low users of health care will save by getting HDHP+HSA plans (provided you have a plan for how to pay when an accident or something happens) and high users (persons having babies, diagnosed with cancer, ms, whatever) save with full coverage. The one caveat is sometimes childbirth services are separated from other types of hospital care, and when they are, it's often cheaper on those plans. I'm expecting this option to go away though as plan services are being more and more regulated to allow for apples to apples comparisons.
You two don't have to be on the same plan. I have a regular job with insurance and my husband does a combination of self-employment and part-time gigs. I get my insurance through work (planning on having a kid) and we get my husband an HSA plan on the private market - the only time it made sense to have him on my plan was when my employer covered almost all of it. Check both the regular market (e.g. ehealthinsurance) and your state's health exchange (though if your employer offers your partner insurance, you can't get a subsidy). The two should be leveling out soon, but the products on the private market are changing quite a bit. There are definite winners and losers w/ Obamacare (husband's premiums are increasing, but for the first time I can get insurance outside of my job should I need it), so find out how the numbers apply to your situation.
Finally, this time next year if there's no ragamuffin in sight and your feeling anxious about it, you might also want to compare fertility services on your plan options. Coverage for this is pretty low so it could be a significant expense.