I did my third trimester detailed scan about 2.5 weeks ago (early May 2020), my husband joined me in the ultrasound room after the sonographer was done with taking the measurements. It seems to be a norm that partners/ spouses get called in after the measurements are done. The rooms are all very small, so I think it's more of a space constraint. I follow up in SGH and till date they still allow 1 accompanying caregiver for outpatient visits. I do have check up for another medical discipline there, besides o&g. Not sure if there's varying practice across different healthcare institutions, maybe you could clarify with the facility you're following up with?
That’s the norm during the circuit breaker. As for what happens after that, I’m not sure if they’ll revert to the old policy immediately or only after some time (previously I could even have more than 1 family member with me). You may want to ask your hospital... take care and stay safe!
On usual days you are allowed a companion but I guess it is because of the CB period that government hospital restricts it. Some private hospital still allow though.