If you look for a local one try ICBC AXA. Know a few expats who use them while via the broker https://asiahealth.com/china/
Not too sure what there min insurance period is before you they cover pregnancy.
If you look fora international expat one then try William Russel, Cigna, Bupa, Now Health or there is a few danish health insurance provider that offer by far the most comprehensive plans – but a bit pricy as they currently only offer plans where you pay once or twice a year. I ended up with a Swiss one called Helsana. But they only reimburse you onto a bank account in Switzerland. helsana.ch