Wife's green card expired. There were delays because of pregnancy, etc. Is the I130 an option or is there something else?

Great question - on its face, starting over from scratch with a new I-130 does appear to be the most obvious answer. BUT - there is one other possibility, and it may fit this situation rather well.

There is something called a "Returning Resident" visa, technically called an "SB-1." You apply directly to the U.S. consulate nearest you abroad for this. They usually tell you to allow at least three months for processing.

To get it you need to show that on departure, your wife was a permanent resident when she left the U.S., that she still had this intent during the time she remained abroad (which was only intended to be temporary), and that the protracted nature of the stay was due to reasons beyond her control and for which she wasn't responsible (a doctor's note saying that she was advised against travelling while in late pregnancy/with a newborn would help here), and that she remains otherwise eligible for the immigrant visa (still married to you as a U.S. citizen, you can still provide financial support, still no criminal or other grounds for exclusion, etc.

I'm attaching the link to the general U.S. state Department info page on this, but check with the consular post nearest you.

Good luck - and congrats on the new addition (from another new dad!)

Another option is to file the I-751 late; they will issue a receipt which she can use with the PR card to reenter the U.S. and then this woudl be adjudicated based on good faith marriage etc. It is not clear from the facts if she has been out of the U.S. for more than a year or that the expiration date is more than a year ago. If out of the U.S. more than a year without a reentry permit there could be abandonment issues so a new I-130 woudl be required.

adding to previous answer: If USC has been resident abroad for more than 6 months may be able to file I-130/ DS-230 at U.S. consulate/ USCIS overseas office; if not eligible for late I-751.

Cover your bases and do all at the same time. Late filed I-751's that are accepted may be presumed preserve her status. Plan to enter altogether, since you may have to initially fight this battle in secondary inspection at the airport on your return. By entering together, you may be able to convince CBP officials that you didn't plan to abandon residence. I have seen discretion exercised in this type of situation for longer departure periods when there was a US citizen spouse or adult child reentering with the foreign national.

Alternatively, CBP may give your wife a couple of options: 1) abandon LPR status and enter as a visitor without a visa or 2) be placed in removal proceedings before an immigration judge. If the I-751 is accepted, the burden is on the CBP to take the green card status away, that is why they would have to place her in proceedings.

The only reason to file the I-130 now would be on the off chance she gets turned around at the airport. Ideally you should have a lawyer to discuss your entry with the port before you arrive and have all the evidence prepared ahead of time.