Table 2 Inclusion and exclusion criteria of the included trials
Study | Inclusion criteria | Exclusion criteria |
|---|---|---|
Schorret al, 1997 [27] | GA >37 wks | Patient exclusion factors were placenta previa, evidence of fetal compromise, intrauterine growth restriction, and rupture of membranes. |
Dugoff et al, 1999 [9] | GA ≥36 wks, breech presentation (not transverse or oblique lie); reactive NST; intact membranes with a minimum 2 ×2 cm pocket of amniotic fluid | Gross fetal anomalies, uterine malformation, EFW >4000 g, IUGR, placenta previa; known maternal history of third-trimester vaginal bleeding; labor, no contraindications to spinal anesthesia or terbutaline |
Mancuso et al, 2000 [8] | At least 18 y with singleton pregnancies of at least 37 wks in breech or transverse presentations, intact membranes, EFW between 2000 and 4000 g, reassuring FHR testing | Placenta previa, prior classical cesarean delivery, third-trimester bleeding, AFI <5 cm or >25 cm, known uterine malformation, uncontrolled hypertension, suspected major fetal anomaly, active-phase labor |
Weiniger et al, 2007 [28] | ASA status I-II, GA 37e40 wks, no fetal abnormality | Previous uterine surgery or uterine anomaly, contraindication for vaginal delivery and for regional analgesia, patient refusal of regional analgesia, neuropathy, severe back pain with neurological radiation, poor communication, BMI ≥ 40 kg/m2 |
Weiniger et al, 2010 [29] | ASA status I-II, GA 37-40 wks, no fetal abnormality (including IUGR), no contraindication for vaginal delivery and for regional analgesia | Previous cesarean delivery, previous myomectomy with uterine cavity penetration or uterine anomaly, BMI ≥40 kg/m2, AFI <7 cm, neuropathy, severe back pain with radicular radiation, request for elective cesarean delivery |
Burgos et al, 2013 [11] | GA ≥37 weeks, singleton pregnancy, informed consent obtained | ECV were placenta previa, placental abruption, uterine malformation, oligohydramnios, signs of fetal distress, fetal death, severe fetal malformations, multiple pregnancy, Rh incompatibility, clotting disorders, and any indications for cesarean section, contraindication to surgery or N2O use. |
Munoz et al, 2014 [12] | 36–41 weeks of gestation with a non-cephalic presentation confirmed by ultrasound scan | Fetal abnormalities, intrauterine fetal death, suspicion of fetal growth restriction, fetal weight above 3800 g, maternal cardiovascular disease, American Society of Anesthesiologists class >2, severe hypertension, allergy to any trial medications, amniotic fluid index<4 cm, Doppler cerebroplacental ratio >5th percentile, abnormal cardiotocographic recordings, contraindications to vaginal delivery, uterine abnormalities, coagulation disorders, Rhesus incompatibility, multiple gestation, rupture of membranes and/or placental abruption |
Khaw et al, 2015 [10] | American Society of Anesthetists status I-II, term parturients, breech-presenting fetus | Contraindications to ECV including patients with known uterine scar or anomaly, unexplained third-trimester bleeding, obstetric or medical conditions complicating pregnancy, compromised fetus, nuchal cord, fetal anomaly, premature rupture of membranes, labor |
Liu et al, 2016 [14] | The study population consisted of singleton pregnancies with breech presentation at term (≥37 weeks), confirmed by ultrasound | History of prior uterine surgery, uterine abnormalities, multiple pregnancy, contraindications to vaginal delivery, maternal cardiovascular disease, severe hypertension, American Society of Anesthesiologists class >2, allergy to the trial medications, prelabor ruptured membranes, placental abruption, fetal anomaly, intrauterine fetal death, and fetal weight above 3800 g. In addition, participants who received ECV, and also the moxibustion therapy, to correct the breech presentationat before the study recruitment were also excluded |
Wang et al, 2017 [30] | Nulliparous women with singleton BP at term (≥37+0 weeks), and the eligibility of all subjects was confirmed with ultrasound examination | Subjects were excluded in the presence of fetal abnormalities, intrauterine fetal death, multiple pregnancy, prior uterine surgery, maternal cardiovascular disease, severe hypertension, fetal weight >3800 g, American Society of Anesthesiologists class >2, allergy to remifentanil and its placebo, ruptured membranes, and placental abruption |
Yang et al, 2019 [31] | Full term (≥37 weeks), singleton, breech | History of scarred uterus, abnormal placental position, uterine anomalies, severe comorbidities or complications, and contraindications to vaginal delivery |
Dochez et al, 2020 [15] | GA of at least 36 weeks and scheduled for external cephalic version | Maternal age younger than 18 years, relative contraindications for ECV (contraindication to vaginal delivery, placenta previa, intrauterine fetal death, oligohydramnios, fetal heart rate abnormalities or maternal HIV seropositivity), and contraindications linked to the equimolar mixture of N2O and oxygen (pneumothorax, ophthalmic gases [SF6, C3F8, or C2F6] in the 3 months before ECV, alteration of consciousness, or need for continuous oxygen therapy for a pulmonary illness) |
Zhang et al, 2020 [32] | Singleton pregnancy, no umbilical cord entanglement by ultrasound, fetal position is breech | Contraindications to intralesional anesthesia such as abnormal intracranial pressure, BMI over 40 kg/m2, gestational diabetes mellitus, gestational hypertension and other gestational syndromes; multiple pregnancies |
Han et al, 2020 [33] | Primigravida with singleton pregnancy, gestational cycle of (37±2) weeks, fetal position in breech position diagnosed by ultrasound, no cord entanglement, familiar with and aware of the whole experimental study, and voluntarily enrolled | Patients with multiple pregnancies or trans-pregnant women, pregnant women with gestational hypertension, diabetes mellitus and other gestational syndromes, patients with BMI>40 kg/m2 and patients with intracranial pressure abnormalities and other contraindications to intravertebral anesthesia are excluded |
Straube et al, 2021 [34] | At least 18 years old, 37-weeks' gestation or beyond, singleton pregnancy, breech presentation, and American Society of Anesthesiology physical status I-III | Non-English speaking, patient refusal, contraindication to N2O use (recent eye or brain surgery or pneumothorax), and patients who were receiving NA for ECV |
Yang et al, 2023 [35] | Singleton pregnancy; a noncephalic presentation at 36–38 weeks gestation and scheduled for ECV | Cesarean delivery cannot be avoided, diagnosed with placenta previa or twin pregnancy; contraindications were early labor, oligohydramnios or rupture of membranes, severe fetal growth restriction, uterine malformation, prior abruption, and prior cesarean delivery; incomplete history and surgery records were available; and participants requested repeat cesarean delivery during delivery. |