Does turning 30 really change that much??

Before I got pregnant, I decided to get in shape and I lost 60 pounds over 8 months. I was dropping between 1.5-4lb a week doing WW and working out about 6-10 hours a week. Combo of Body Pump, Spinning, Jogging, and pilates. Now I started again about 1.5 years after my son was born. I'm 30 (31 in mid-July) and I'm doing a lot of the same things. I've replaced Weight Watchers with MFP, and I don't have a gym membership anymore, so now I'm doing Body Pump, running, and some other strength and cardio exercises (Beach Body mostly, P90X, Body Combat, 10 minute trainer, etc). I'm still losing, but on average it takes 2 weeks to lose a pound. It's so frustrating because I'm working hard and cutting calories--doing what gave me great success in the past, and now it's taking so much longer. Is this really just because I turned 30? Is it because of the baby? Is there a different combo I should be trying since I'm over 30 and have a kid now that works better than in your 20s/pre baby?
ETA: I'm actually eating less than I was on WW because MFP suggests a lower caloric intake *and* I'm not eating back most of my workout calories whereas on WW they give you bonus weekly points (42, I think) and exercise points, and I'd usually eat at least 30 of those back. I thought larger caloric deficit = more weight loss, which is why I cut those out.