stable period; period of stability
General term for a time when things are settled and not changing much.
The economy has entered a stable period.
stable stage of pregnancy
Specifically refers to the period from around the 12th week of pregnancy onward, when the risk of miscarriage decreases.
Once I enter the stable stage of pregnancy, I plan to arrange a trip.
安定期 describes a period of stability and calm, the opposite of the unsettled, changing nature of 過渡期.
Compound of 安定 (antei, 'stability') + 期 (ki, 'period').