The OCT test takes 20-30 minutes. When fetal movement decreases or increases, intrauterine distress is suspected. To understand the fetal intrauterine reserve capacity, a contraction provocation test is performed to induce regular contractions and continuous electrical fetal heart monitoring is performed for 20-30 minutes to observe the change of fetal heart during contractions. If there is recurrent late decelerations, recurrent variable decelerations or bradycardia, consider category III fetal monitoring and acute intrauterine fetal distress and terminate the pregnancy by immediate cesarean delivery. If the baseline fetal heart rate is 110-160 beats/min, variability is 6-25 beats/min and there is no deceleration of contractions, it is category 1 fetal monitoring, which means that the fetus does not show intrauterine hypoxia and does not need to be treated, continue regular perinatal care and observe fetal movement. If the fetus is still in category 2 or category 3 fetal monitoring after repeated review, timely termination of pregnancy should be considered.