Subjects

A total of 234 primiparas with single head positions who gave birth from January 2019 to January 2020 in our hospital were enrolled in this study and were randomly divided into three groups (in each group n = 78). The statistical software SPSS 22.0 was used to input the estimated sample size, generate the serial number, make the random card, put the envelopes coded in order, impervious to light and sealed, and distribute the envelopes according to the order of entering the group, and divide the selected women into 76-cases in TEAS and 75-cases in the epidural group and 78-cases in the control group that have not taken analgesic measures.

In the TEAS group, two patients shifted to an epidural block halfway because they were not satisfied with the analgesic effect of TEAS, one patient failed to complete the analgesic treatment, and the visual analog scores (VAS) of each period was withdrawn from the study due to precipitate labor. In the PCEA group, two patients failed to complete the analgesic treatment, and the VAS of each period was withdrawn from the study due to precipitate labor. Consequently, 75 cases in the TEAS group, 76 cases in the PCEA group, and 78 cases in the control group were included. The differences in age and gestational age among the three groups were not statistically significant (P > 0.05). Hence, the three groups were comparable. This study was approved by ethics Committee of Affiliated Hospital of Qingdao University (approval No.: QYFYWZLL25584).

1) Primiparas with single birth and head presentation; 2) 37–41 weeks of pregnancy; 3) primiparas without cephalopelvic disproportion, intending a vaginal delivery, and without contraindications of vaginal delivery. 4) Regular contractions, the opening of the cervix was >3 cm wide. 5) Puerpera and their family members agreed to implement labor analgesia and sign informed consent.

1) Skin damaged in the application area of the electrode piece or puncture area of PCEA. 2) Severe internal and external complications, or obstetric complications such as hypertension, diabetes, heart disease, or trauma. 3) Other analgesic measures or drugs have been used before analgesia. 4) Precipitate labor or family history of precipitate labor.

The criteria were based on Obstetrics and Gynecology,⁶ 9th Edition, edited by Xie Xing, People’s Health Publishing House.

The first stage of labor: the time from the beginning of regular contractions to the cervix fully opening.

The second stage of labor: the time from when the cervix was fully opened until the delivery of the fetus.

The third stage of labor: the time from the delivery of the fetus to the delivery of the placenta.

Visual analog score (VAS): The basic method is as follows: a numerical scale about 10 cm long is used, marked with 10 scales on one side, with 0 and 10 point ends at both ends. A VAS of 0 points: no pain; ≤3 points: slight pain, tolerable; 4–6 points: the patient has pain that affects sleep, but can still endure it; 7–10 points: the patient is gradually developing intense pain, which is unbearable, affecting appetite and sleep. The VAS was recorded immediately before analgesia, at 30 minutes, 60 minutes, and 120 minutes after analgesia. A decrease in the VAS by ≥3 points was considered as effective analgesia.

Apgar score of the newborn: This consists of five physical signs: heart rate, respiration, muscle tension, laryngeal reflex, and skin color, with a full score of 2 points for each item.