Would love to know this too:)
I searched when I was pregnant and could only find pregnancy yoga. You can keep doing Pilates, just skip the ab exercises. My instructor was pregnant and did some online pregnancy Pilates classes which are available on demand. https://www.fitbybee.com/prenatal Tribe Yoga have a mum and baby barre class at quartermile for after your little one arrives.
I can highly recommend Pilates by Tess on a Thursday night at 6pm in the old schoolhouse in Morningside.
I haven’t got a recommendation but is Pilates something you have done before you were pregnant? I considered this option but not sure on if I should do yoga instead (I haven’t done either before I was pregnant)