Methods
Study design
We examined data from all pregnant women who received care at the International Peace Maternity & Child Healthcare Hospital (IPMCHH), Shanghai Jiaotong University from Jan. 1, 2007, through Dec. 31, 2013. IPMCHH is the largest obstetric care center in Shanghai, with 11,000-16,000 annual deliveries; >90% women are nulliparous because of the 1-child policy in China.
Study population
Eligibility criteria for the current study included singleton term nulliparous women with vertex presentation; women with major fetal anomalies or stillbirth before hospital admission and multiparous women were excluded.
Data collection
The IPMCHH research group and information engineer extracted and abstracted data from the hospital electronic medical record according to criteria set forth on the standardized data collection form. Types of information that were abstracted included maternal demographic characteristics, medical history, reproductive and prenatal history, labor and delivery summaries, and postpartum and neonatal information. The data were then deidentified before analysis. The study was approved by the ethics review board at IPMCHH and the institutional review board at The Ohio State University.
Operational definitions
Labor was defined as regular uterine contractions and cervical dilation of ≥2 cm. CD performed before labor was categorized as an antepartum CD, whereas intrapartum CD was an operation performed after a trial of labor. CDMR was defined as an antepartum cesarean delivery that was performed on maternal request without medical indications. Cases of CDMR could be identified in this study because IPMCHH requires that a signed patient consent form that outlines the risks and benefits of CD be retained in the medical record. In this study, in addition to CDMR, there were 2 types of antepartum CD that included indicated CD and CD with borderline indications listed (such as postterm/postdates, diabetes mellitus, chorioamnionitis, obesity, chronic or gestational hypertension without preeclampsia/eclampsia, premature rupture of the membranes, human papillomavirus infection, group B streptococcus positive, and polyhydramnios. Planned vaginal deliveries included all deliveries after a trial of labor: spontaneous vaginal birth, assisted vaginal delivery (vacuum or forceps), or intrapartum CD performed because of abnormal progress of labor or nonreassuring fetal heart rate status.
Maternal death was defined as death during the first 6 weeks after delivery. Severe postpartum hemorrhage (PPH) included those women who met at least 1 of following criteria: required blood transfusion, postpartum decrease of hemoglobin ≥4 g/dL-1 (the last hemoglobin value before delivery was considered to be the reference), required Bakri balloon placement, placement of B-Lynch suture, uterine artery embolization or hysterectomy, dilation for bleeding, or retained placental tissue. Mild PPH was defined as estimated blood loss >500 mL in the first 24 hours after vaginal delivery and after CD but could not meet the criteria of severe PPH. Maternal infection was defined as maternal fever of at least 38.5°C on 2 occasions at least 24 hours apart (not including the first 24 hours), pneumonia, urinary tract infection, pelvic inflammatory diseases, wound infection, wound dehiscence, or breakdown. Maternal organ injury included third- or fourth-degree perineum laceration, genital-tract fistula, rectum injuries, cervical laceration that involved the lower uterine segment (in the case of a vaginal delivery), and injuries to intraperitoneal organs such as bladder, ureter, and intestine. Maternal thromboembolic disorders included deep-vein thrombosis, pulmonary embolism, and amniotic fluid embolism. The incidence of maternal transfer to the intensive care unit (ICU) was included as maternal outcome. The occurrence of complications was also counted accordingly if the women were readmitted to the hospital.
Perinatal death was defined as intrapartum stillbirth or neonatal death at <28 days of age. Birth trauma included subdural hematoma, intracerebral or intraventricular hemorrhage (diagnosed based on the combination of abnormal neurologic examination with computer tomography scan finding), basal skull fracture, and/or facial or brachial plexus nerve injury that was present at discharge from hospital. Neonatal infection included pneumonia, sepsis, meningitis, or antibiotic treatment for ≥3 days. The other neonatal morbidity included hypoxic ischemic encephalopathy, meconium aspiration syndrome, respiratory-distress syndrome, and necrotizing enterocolitis. The incidence of neonatal ICU (NICU) admission was also used as neonatal outcome.
Covariates
Based on review of the literature, the following covariates were considered to be potential confounders or effect modifiers: maternal age, prepregnancy body mass index, education, insurance status, marital status, type of conception, birthweight, gestational week at delivery, group B streptococcus infection and sexually transmitted diseases, maternal chronic medical conditions, and pregnancy complications.
Statistical analysis
Deidentified annual data were concatenated to create a single large dataset. Data were examined for missing and extreme values and logic checked. Descriptive statistics included means and standard deviations for continuous variables and numbers and percentages for categoric variables. The differences between 2 groups were assessed with the use of χ 2 tests for dichotomous outcomes and the Wilcoxon rank-sum test for continuous variables. Logistic regression was used to determine the odds ratios (ORs) and 95% confidence intervals (CIs) of perinatal death, serious maternal morbidity and ICU admission, serious neonatal morbidity and NICU admission, and mild PPH. A multiple linear regression model was used for continuous outcomes (maternal length of stay). The odds ratios and differences were adjusted for maternal age, prepregnancy body mass index, insurance status, education levels, type of conception, sexually transmitted diseases, maternal chronic medical conditions, pregnancy complications, birthweight, and gestational week at delivery. All data were analyzed with SPSS software (version 21; IBM Corp, Chicago, IL). A probability value of < .05 was considered statistically significant.
Results
We abstracted data on 81,482 pregnancies to 79,103 unique women who received care at IPMCHH from 2007-2013. After restricting the sample to the inclusion and exclusion criteria, we were left with 66,226 deliveries (81.3%) to the same number unique women who were available for analysis.
The Figure shows the flow chart of the study population. A total of 40,560 women (61.2%) had planned vaginal delivery: 32,833 women (80.9%) had spontaneous vaginal deliveries; 4990 women (12.3%) had intrapartum CD, and 2737 women (6.7%) had assisted vaginal delivery. A total of 16,333 women (24.7%) underwent antepartum CDMR with a signed patient consent form that outlined the risks and benefits of CDMR, and 4611 antepartum CDs (7.0%) were performed with borderline indications. The other 4722 women (7.1%) had procedures that were performed antepartum CD with medical indications.
More than 99% of the women in our study population were of Han ethnicity. Smoking or alcohol use was very uncommon in this population (data not shown). Other baseline and obstetric characteristics of the study subjects are shown in Table 1 . Older, overweight, or obese women or women whose condition was complicated with other medical disorders or sexually transmitted diseases were more likely to undergo CDMR ( P < .001). Also, women with larger fetuses or those conceived after assisted conception were more likely to choose CDMR ( P < .001). Women who underwent planned vaginal delivery were better educated, more likely to have social or medical insurance, and delivered at a later gestational age. There were no differences between the 2 groups with respect to group B streptococcus infection and marital status. There were 12,616 women (31.1%) in the planned vaginal delivery group who underwent induction; 13,516 women had (33.3%) had epidural during labor, and 131 women (0.8%) decided during admission for induction to undergo CDMR without labor. The majority of antepartum or intrapartum CD were performed with epidural/spinal anesthesia (99%; data not shown).
| Characteristic | Cesarean delivery on maternal request (n = 16,333) | Planned vaginal delivery (n = 40,560) | P value |
|---|---|---|---|
| Maternal age, n (%) | < .001 | ||
| ≥35 y | 2621 (16.0) | 1415 (3.5) | |
| 30-34 y | 6090 (37.3) | 14,855 (36.6) | |
| 25-29 y | 7008 (42.9) | 21,700 (53.5) | |
| 20-24 y | 609 (3.7) | 2556 (6.3) | |
| <20 y | 5 (0.0) | 34 (0.1) | |
| Insurance, n (%) | 11,308 (69.2) | 29,088 (71.7) | < .001 |
| Married, n (%) | 16,253 (99.5) | 40,338 (99.5) | .393 |
| Body mass index at first prenatal visit, n/N (%) a | < .001 | ||
| <20 kg/m 2 | 1289/15,353（8.4） | 4804/38,127 (12.6) | |
| 20-24 kg/m 2 | 9810/15,353 (63.9) | 26,117/38,127 (68.5) | |
| 25-29 kg/m 2 | 3700/15,353 (24.1) | 6748/38,127 (17.7) | |
| ≥30 kg/m 2 | 554/15,353 (3.6) | 458/38,127 (1.2) | |
| Education, y b c | 15.0 ± 2.8 | 15.2 ± 2.8 | < .001 |
| Assisted conception, n (%) | 815 (5.0) | 249 (0.6) | < .001 |
| Induction, n (%) | 131 (0.8) | 12,616 (31.1) | — |
| Epidural during labor, n (%) | — | 13,516 (33.3) | — |
| Group B streptococcus, n/N (%) d | 539/15,971 (3.4) | 756/20,275 (3.7) | .072 |
| Sexually transmitted disease, n/N (%) e | 279/16,306 (1.7) | 215/40,302 (0.5) | < .001 |
| Complicated with other medical disorders, n (%) f | < .001 | ||
| No | 13,988 (85.6) | 36,829 (90.8) | |
| Yes | 2345 (14.4) | 3731 (9.2) | |
| Birthweight, n (%) | < .001 | ||
| ≥4000 g | 943 (5.8) | 1793 (4.4) | |
| 3500-3999 g | 5919 (36.2) | 12,184 (30.0) | |
| 2500-3499 | 9389 (57.5) | 26,306 (64.9) | |
| <2500 g | 82 (0.5) | 277 (0.7) | |
| Gestational week at delivery, n (%) | < .001 | ||
| 37 +0 -38 +6 | 6911 (42.3) | 11,049 (27.2) | |
| 39 +0 -40 +6 | 8768 (53.7) | 26,132 (64.4) | |
| ≥41 | 654 (4.0) | 3379 (8.3) |
a The weight in kilograms divided by the square of the height in meters; values were missing for 3413 women (6.0%)
b Values were missing for 3357 (5.9%) women
d 20,647 (36.3%) women did not undergo this test
e Values were missing for 285 (0.5%) women
f Complicated by at least 1 of cardiac disease, hepatitis, renal disease, diabetes mellitus and gestational diabetes mellitus, chronic hypertension and gestational hypertension, thyroid disease, preeclampsia, and/or intrahepatic cholestasis of pregnancy.
There were no maternal deaths in either group. Some women had a critical clinical course (there were 3 cases of amniotic fluid embolism); however, none of these women died. We observed no significant differences between groups in the frequencies of the maternal ICU admission (0.2% and 0.2% in the CDMR and planned vaginal delivery groups, respectively; adjusted OR [aOR], 0.89; 95% CI, 0.58–1.35; P = .569; Table 2 ). The individual maternal morbidity of severe PPH (0.5% vs 0.5%), maternal infection (1.3% vs 1.3%), and thromboembolic disorders (0.1‰ vs 0.1‰) did not differ significantly between the 2 groups. There were 4 bladder injuries, 1 ureter injury, and 1 intestinal injury in the CDMR group. In the planned vaginal delivery group, there were 16 women complicated with third- and fourth-degree perineal lacerations, 1 genital-tract fistula, 2 cervical lacerations that involved the lower uterine segment, and 3 bladder injuries during intrapartum CD. The general incidence of organ injuries did not differ in the 2 groups (0.4‰ vs 0.5‰). Women who underwent CDMR were less likely to experience complications with mild PPH (1.7% vs 3.4%; aOR, 0.44; 95% CI, 0.39–0.51).
| Outcomes | Cesarean delivery on maternal request (n = 16,333) | Vaginal trial (n = 40,560) | Odds ratio or difference (95% confidence interval) | P value | |
|---|---|---|---|---|---|
| Unadjusted | Adjusted | ||||
| Maternal death, n (%) | 0 | 0 | — | — | — |
| Serious maternal morbidity | |||||
| Severe postpartum hemorrhage, n (%) | 76 (0.5) | 194 (0.5) | 0.97 (0.75–1.27) | 0.94 (0.71–1.24) | .651 |
| Maternal organ injury, n (‰) | 6 (0.4) | 22 (0.5) | 0.68 (0.28–1.67) | 0.61 (0.24–1.55) | .294 |
| Maternal infection, n (%) | 213 (1.3) | 535 (1.3) | 0.99 (0.84–1.16) | 1.06 (0.90–1.25) | .493 |
| Embolism, n (‰) | 3 (0.1) | 5 (0.1) | — | — | — |
| Intensive care unit admission, n (%) | 32 (0.2) | 90 (0.2) | 0.88 (0.57–1.38) | 0.89 (0.58–1.35) | .569 |
| Mild postpartum hemorrhage, n (%) | 271 (1.7) | 1378 (3.4) | 0.48 (0.42–0.55) | 0.44 (0.39–0.51) | < .001 |
| Maternal length of stay (d) b | 5.7 ± 2.4 | 4.3 ± 1.9 | 1.4 (1.41–1.48) | 1.5 (1.50–1.57) | < .001 |
| Perinatal death, n (‰) | 6 (0.4) | 24 (0.6) | 0.62 (0.25–1.52) | 0.51 (0.20–1.30) | .159 |
| Serious neonatal morbidity | |||||
| Birth trauma, n (‰) | 3 (0.2) | 43 (1.1) | 0.17 (0.05–0.56) | 0.14 (0.04–0.48) | < .001 |
| Neonatal infection, n (%) | 65 (0.4) | 276 (0.7) | 0.58 (0.45–0.77) | 0.56 (0.43–0.75) | < .001 |
| Hypoxic ischemic encephalopathy, n (‰) | 7 (0.4) | 72 (1.8) | 0.24 (0.11–0.52) | 0.22 (0.10–0.47) | < .001 |
| Meconium aspiration syndrome, n (‰) | 3 (0.2) | 26 (0.6) | 0.29 (0.09–0.95) | 0.29 (0.08–0.97) | .045 |
| Respiratory-distress syndrome, n (%) | 90 (0.6) | 148 (0.4) | 1.51 (1.16–1.97) | 1.32 (1.00–1.74) | .048 |
| 37 +0 -38 +6 gestational week, n/N (%) | 53/6911 (0.8) | 53/11,049 (0.5) | 1.60 (1.09–2.35) | 1.51 (1.01–2.25) | .045 |
| 39 +0 -40 +6 gestational week, n/N (%) | 32/8768 (0.4) | 81/26,132 (0.3) | 1.18 (0.78–177) | 1.09 (0.71–1.65) | .701 |
| ≥41 gestational week-n/N (%) | 5/654 (0.8) | 14/3379 (0.4) | 1.85 (0.67–5.16) | 1.90 (0.68–5.32) | .220 |
| Necrotizing enterocolitis, n (‰) | 15 (0.9) | 21 (0.5) | 1.77 (0.92–3.44) | 1.59 (0.80–3.16) | .187 |
| Neonatal intensive care unit admission, n (%) | 495 (3.0) | 1503 (3.7) | 0.81 (0.73–0.90) | 0.79 (0.71–0.88) | < .001 |
a Vaginal trial group was the reference
No significant difference was observed between the CDMR and planned vaginal delivery groups in perinatal mortality rate (0.4‰ vs 0.6‰; aOR, 0.51; 95% CI, 0.20–1.30; P = .159). The details of all perinatal deaths in the 2 groups are found in the Table 3 . Compared with planned vaginal delivery, there were reductions with CDMR in the frequencies of NICU admission (3.0% vs 3.7%; P < .001), neonatal infection (0.4% vs 0.7%; P < .001), hypoxic ischemic encephalopathy (0.4‰ vs 1.8‰; P < .001), and meconium aspiration syndrome (0.2‰ vs 0.6‰; P = .045). In the CDMR group, there were 2 cases of temporary facial nerve injury associated with the use of short-arm Simpson forceps and 1 case of intraventricular hemorrhage. In the planned vaginal delivery group, there were 8 cases of brachial plexus nerve injury, 3 cases of basal skull fracture, 5 cases of facial nerve injury, and 27 cases of subdural hematoma, intracerebral/intraventricular hemorrhage. The general incidence of birth trauma was lower in the CDMR group (0.2‰ vs 1.1‰; P < .001). However, CDMR was associated with an increased risk of respiratory distress syndrome (0.6% vs 0.4%; aOR,1.32; 95% CI, 1.00–1.74; P = .048), specifically when the gestational age at delivery was between 37 +0 -38 +6 weeks. The women who had CDMR stayed longer in hospital (β = 1.5 days; 95% CI, 1.50-1.57; P < .001) than those who had planned vaginal delivery.
| No | Delivery method | Main information |
|---|---|---|
| 1 | Vaginal birth | BW = 3120 g; FHR abnormalities; intrapartum stillbirth |
| 2 | Vaginal birth | BW = 3078 g; cord prolapse; intrapartum stillbirth |
| 3 | Vaginal birth | BW = 3064 g; FHR abnormalities and placenta abruption; intrapartum stillbirth |
| 4 | Vaginal birth | BW = 3240 g; severe asphyxia and hypoxic ischemic encephalopathy; neonatal death |
| 5 | Vaginal birth | BW = 2204 g; group B streptococcus infection, meningitis, and sepsis; neonatal death |
| 6 | Vaginal birth | BW = 2736 g, intrauterine infection and necrotizing enterocolitis; neonatal death |
| 7 | Vaginal birth | BW = 3255 g; FHR abnormalities; intrapartum stillbirth during cesarean delivery preparation |
| 8 | Vaginal birth | BW = 2740 g; severe asphyxia; neonatal death |
| 9 | Vaginal birth | BW = 3320 g; FHR abnormalities; intrapartum stillbirth |
| 10 | Vaginal birth | BW = 3140 g; woman came to emergency room with a full cervical dilation; stillbirth |
| 11 | Vaginal birth | BW = 2725 g; meconium aspiration syndrome and pulmonary artery hypertension; neonatal death |
| 12 | Vaginal birth | BW = 2800 g; hypoxic ischemic encephalopathy and intraventricular hemorrhage; neonatal death |
| 13 | Vaginal birth | BW = 3255 g; intrapartum stillbirth with meconium-stained fluid |
| 14 | Vaginal birth | BW = 2740 g; severe asphyxia and intrauterine infection; neonatal death |
| 15 | Vaginal birth | BW = 3390 g; vessel previa in velamentous placenta; intrapartum vaginal bleeding; intrapartum stillbirth |
| 16 | Vaginal birth | BW = 3720 g; FHR abnormalities; intrapartum stillbirth during forcep preparation |
| 17 | Vaginal birth | BW = 3420 g; intrapartum bleeding; intrapartum stillbirth |
| 18 | Vaginal birth | BW = 3980 g; shoulder dystocia, severe asphyxia, and intraventricular hemorrhage; neonatal death |
| 19 | CDMR | BW = 3315 g; amniotic fluid embolism during cesarean delivery; stillbirth in operation |
| 20 | CDMR | BW = 3555 g; pulmonary edema and heart failure; neonatal death |
| 21 | CDMR | BW = 3890 g; pneumonia and sepsis; neonatal death |
| 22 | CDMR | BW = 2850 g; respiratory distress syndrome; neonatal death |
| 23 | CDMR | BW = 3265 g; severe asphyxia; neonatal death |
| 24 | CDMR | BW = 3990 g; sudden death with no clear reason after discharge; neonatal death |
| 25 | Intrapartum CD | BW = 2882 g; severe asphyxia and intrauterine infection; neonatal death |
| 26 | Intrapartum CD | BW = 3146 g; spontaneous uterus rupture; intrapartum stillbirth |
| 27 | Intrapartum CD | BW = 3275 g; intrauterine infection and meningitis; neonatal death |
| 28 | Intrapartum CD | BW = 3720 g; forceps-assisted vaginal delivery failure, then intrapartum cesarean delivery, severe asphyxia; neonatal death |
| 29 | Assisted vaginal delivery | BW = 3452 g; difficult forceps-assisted vaginal delivery; stillbirth |
| 30 | Assisted vaginal delivery | BW = 3704 g; severe asphyxia, intraventricular hemorrhage; neonatal death |
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
