I am not a huge fan of machines unless they are used for rehabilitation purposes, but they have definitely been a life saver throughout my pregnancy! Using machines for exercises like weighted leg presses, quad and hamstring pulls/presses are a great substitute for when that belly gets to big and heavy to dead lift.
Although, don't forget to continue with plain old squats! They can help move baby into position for labor and strengthen pelvic floor muscles.
Also using resistance bands or machines for lat pull downs, bicep curls, triceps and rowing will help keep tone and definition in your arms chest and back.
The incline bench allows pregnant women to continue to work the chest when lying on your back is no longer an option!