How long does it take for the cervical canal to regress by 60% until birth

Cervical canal regression of 60% to delivery usually takes 24-72 hours, and the actual time is affected by factors such as uterine contraction intensity, fetal position, parity, pelvic conditions, and hormone levels.

1. Contraction intensity:

Regular contractions are a key factor in promoting the regression of the cervical canal. When the frequency of contractions reaches once every 3-5 minutes and lasts for 40-60 seconds each time, the cervical canal regresses the fastest. If the uterine contractions are weak or the interval is too long, it may be prolonged to 3-5 days. Electronic fetal heart monitoring can quantify uterine contraction pressure, and the efficiency is higher when the pressure value is greater than 60mmHg.

2. Fetal position influence:

The anterior occipital position of the fetal head is most effective in compressing the cervix and can accelerate the regression to 1cm per hour. The regression speed may be reduced by 30% -50% in the breech or transverse position due to insufficient contact surface. Ultrasound examination can confirm fetal position, and abnormal fetal position requires consideration of external reversal surgery.

3. Differences in parity:

The rate of cervical canal regression in multiparous women is usually 50% faster than in primiparous women because the cervical connective tissue has better elasticity. The average time for primiparous women to complete complete complete regression is 48 hours, while multiparous women usually complete it within 24 hours. But those with a history of cervical surgery may delay the process.

4. Pelvic conditions: When the transverse diameter of the pelvic entrance is greater than 12cm and the angle of the pubic arch is greater than 90 °, the smooth descent of the fetal head promotes cervical regression. Narrowing the pelvis can lead to difficulty in connecting the fetal head, causing regression to stagnate at 60% -70% stage, at which point the head pelvic relationship needs to be evaluated.

5. Hormone levels:

The peak secretion of prostaglandins can increase the rate of cervical softening by 2 times, and those with insufficient estrogen levels have a longer regression time. The commonly used Denoprostone suppository in clinical practice promotes cervical maturation, with a completion rate of 78% within 12 hours after medication.

It is recommended to maintain moderate activity during labor, such as ball sports, to promote fetal head descent; Consuming easily digestible foods to supplement energy; Urination every hour should be avoided to prevent bladder filling from affecting fetal position. If there is no progress, abnormal fetal heart rate, or severe abdominal pain after 72 hours, immediate medical intervention is required. Pay attention to perineal care after childbirth, wash with warm water twice a day, and observe the amount and color changes of lochia.