I'm not rich by any stretch of the imagination, but I found room in my budget for a maid beginning in the third trimester of my last pregnancy. Without question, it was the best money I ever spent.
Anyone whose baby belly caused her to nearly fall into a bathtub while cleaning it knows exactly what I'm talking about. All that bending over, scrubbing and chemical exposure can wreak serious havoc on your physical well-being, so why not pass it off to someone else for a little while? It's surprisingly easy to find a reasonably priced cleaning service, plus you won't be spending money on supplies since they provide their own.
If you absolutely can't swing that extra bill, it's probably time to ask your partner to pitch in a little bit more than usual around the house. Also, bear in mind that you won't be back to your old self immediately after childbirth, so you might want to keep the maid/husband on duty for a few extra months, at least.