Is It Safe To Continue Susten 300 Mg Without Symptoms Of Miscarriage?

Hi Doc,
My wife is pregnant and her last cycle was started on 10th oct . 2 weeks back we gone to doctor and she prescribed to do ultrasonograpy and we did that and she informed that fatal heartbeat is still not able to hear and she told it should come at this time. Orelse some miscarriage might happen and she prescribed to take Susten 300 mg everyday twice. And this news broke both of us and i also got scared after listening this.

But till after 2 weeks my wife has no miscarriage symptoms and she is taking that tablet till date. So is this preferable to continue the same or she need to stop taking that.

Please help me out on this.

Thanks & Regards,
Joy