Caesarean section and subsequent ectopic pregnancy: a systematic review and meta-analysis

Sonographic examination at the beginning of the second stage of labor predicts birth outcome in vaginally intended breech deliveries: a blinded prospective study

PURPOSE

In order to spread competence in vaginal breech deliveries, it is necessary to develop new and easily applicable tools for birth progression and safety evaluation. Ultrasound is a useful and ubiquitously available tool with already documented value for birth progression observation. In deliveries out of breech presentation, an established ultrasound examination is missing. We determined the descent of the fetal buttocks in relation to the maternal pelvic inlet using intrapartum ultrasound. We evaluated these results in comparison to the clinical vaginal examination with the aim to establish an easily applicable method for birth outcome prediction. Therefore, we analyzed the predictive value of our examinations on birth outcome parameters, such as cesarean section rate, as well as fetal and maternal outcome parameters.

METHODS

We performed a prospective blinded study on 106 mothers with vaginally intended breech delivery. At beginning of stage two in labor, the descent of the fetal buttocks into the mother's pelvic inlet was detected with transabdominal ultrasound and vaginal examination by different observers.

PRIMARY OUTCOME VARIABLE

Cesarean section rate. Secondary outcome variables: rate of manual assistance in vaginal deliveries, birth duration, 5' APGAR score, umbilical arterial pH, maternal blood loss, and perineal injury. For non-parametric values, Wilcoxon's χ2 test was performed. In order to analyze the predictive value of our examination, lack-of-fit analysis was conducted. Reliability evaluation of the sonographic examination was done with a matched-pair analysis.

RESULTS

Women with positive intrapartum ultrasound breech engagement sign (+ IPUBES) had a significantly lower rate of cesarean section in comparison with those with negative IPUBES (5/67; 7.5% vs. 18/39; 46.2%; p < 0.0001). The area under the ROC curve for the prediction of CS for negative IPUBES was 0.765 with a sensitivity of 78.3% and a specificity of 74.7%. Sonographic examination showed an excellent reliability in a matched-pair analysis comparing vaginal and sonographic examinations with a mean difference of 0.012 (SD ± 0.027, 95% CI - 0.014 to 0.065). Mean birth duration was significantly longer in deliveries with negative IPUBES (533 min vs. 440 min; p = 0.0011). Fetal and maternal outcome parameters were not significantly different between deliveries with positive and negative IPUBES.

CONCLUSIONS

Sonographic evaluation of the fetal descent in relation to the mother's pelvic inlet screens reliably for emergency cesarean section. This newly presented method for birth progression observation might be a powerful tool for distribution of expertise in vaginal breech delivery and is able to give reference for clinical vaginal examination by obstetricians in training.

TRAIL REGISTRY

Clinical trial. Date of registration: 13.03.2019; Date of initial participant enrollment: 20.03.2019; DRKS00016885; https://www.drks.de ; German clinical trials register.

Different management strategies for cesarean scar pregnancy: Short-term outcomes and reproductive prognosis

PURPOSE

To investigate the impact on future reproductive potential of systemic methotrexate (MTX) administration, uterine artery embolization (UAE) and expectant management as treatments of caesarean scar pregnancy (CSP) and to assess their efficacy and safety.

BASIC PROCEDURES

We retrospectively analysed patients with a diagnosis of CSP treated in a five years' period (2014-2018). Hospitalization, hCG normalization, menstrual cycle recovery, ultrasound restitutio ad integrum times, reproductive desire accomplishment after the resolution of the picture, and outcomes of subsequent pregnancies were considered. Only patients for whom complete diagnosis, treatment and follow-up data were available could be considered for study entry.

MAIN FINDINGS

A total of 21 patients were included. Three of them were managed expectantly. In two cases spontaneous abortion occurred and one case underwent caesarean delivery at 35 weeks of gestation for complete placenta previa with hysterectomy for post partum haemorrhage. Seven patients were treated with systemic MTX. Median [IQR] times of hospitalization, hCG normalization, menstrual cycle recovery and ultrasound restitutio ad integrum were 21 days [10-26 days], 52 days [18-64 days], 8 weeks [6-10 weeks] and 8 weeks [6-11 weeks] respectively. At the end of follow up, 80% (95%CI [38-96%]) of patients with reproductive desire achieved at least one live birth. Eleven patients were treated with UAE combined with MTX. Median [IQR] times of hospitalization, hCG normalization, menstrual cycle recovery and ultrasound restitutio ad integrum were 14 days [12-20 days], 43 days [30-52 days], 8 weeks [4-12 weeks] and 8 weeks [8-10 weeks], respectively. Of those who expressed a reproductive desire after treatment, 80% (95%CI [49-94%]) achieved at least one live birth. In all included patients, the menstrual cycle was restored.

PRINCIPAL CONCLUSIONS

Reproductive potential of women treated for CSP was preserved after both systemic MTX administration and systemic MTX combined with UAE. Both strategies proved to be safe.

Cesarean Scar Pregnancies Treated by Uterine Artery Chemotherapy Embolization Combined With Ultrasound-Guided Dilation and Curettage: A Retrospective Study

OBJECTIVES

To explore the effect of cesarean scar pregnancy (CSP) treatment by comparing uterine artery chemotherapy embolization (UACE) combined with dilation and curettage (D&C) with or without ultrasound guidance.

METHODS

CSP patients treated with UACE combined with D&C from January 2013 to December 2020 at Shuguang Hospital, affiliated to Shanghai University of Traditional Chinese Medicine were included in this retrospective study. The patients were divided into groups A and B according to whether D&C was guided by ultrasound.

RESULTS

Forty-eight patients with CSP diagnosed by transvaginal ultrasound were included in this study, whose gestational age was <8 weeks. There were no significant differences in the basic clinical characteristics of the two groups. The success rates of the 2 groups were no significant difference, 100% (27/27) in group A and 85.7% (18/21) in group B. The maximal intraoperative blood loss of group A was 100 mL and that of group B was 150 mL. There was no uterine perforation during the operation. Ultrasound guidance can shorten the D&C operation time, reduce intraoperative bleeding during D&C, and decrease the residual rate of trophoblastic tissue after D&C.

CONCLUSIONS

Ultrasound guidance can improve the safety and efficiency of UACE combined with D&C in the treatment of CSP and reduce its complications. We believe it is an optimal treatment for CSP patients who do not plan to have children in the future.

Effectiveness, complications, and reproductive outcomes after cesarean scar pregnancy management: a retrospective cohort study

BACKGROUND

There is a dramatic rise in cesarean deliveries worldwide, leading to higher complication rates in subsequent pregnancies. One of these complications is a cesarean scar pregnancy. During the last decades, treatment options for cesarean scar pregnancies have changed, and less invasive interventions have been employed to preserve fertility and reduce morbidity. However, the optimal treatment approach and the influence of various treatments on reproductive outcomes have to be determined.

OBJECTIVE

This study aimed to evaluate the short- and long-term outcomes after cesarean scar pregnancy management.

STUDY DESIGN

We conducted a retrospective cohort study of women determined to have a cesarean scar pregnancy from 2010 to 2021 at a tertiary referral center, the Amsterdam University Medical Center, in the Netherlands. Outcomes of the following management strategies were compared: expectant management, methotrexate, curettage with temporary cervical cerclage, or a laparoscopic niche resection. We performed a curettage if the cesarean scar pregnancy did not cross the serosal line of the uterus, and a laparoscopic niche resection was performed if the cesarean scar pregnancy crossed the serosal line. The main outcomes were treatment efficacy and time to subsequent ongoing pregnancy or pregnancy leading to a live birth.

RESULTS

Of the 60 included women, 5 (8.3%) were managed expectantly, 8 (13.3%) were treated with methotrexate, 31 (51.8%) were treated with a curettage, and 16 (26.7%) with a laparoscopic niche resection. The groups were not comparable. The gestational age and human chorionic gonadotropin levels were generally higher in women who received methotrexate or a laparoscopic niche resection. Additional treatment in the conservative group was needed for 4 (80%) women after expectant management and for 7 (87.5%) women after methotrexate treatment. In the surgical group, all 31 women treated with a curettage and all 16 treated with a laparoscopic niche resection did not require additional treatment. The subsequent ongoing pregnancy rate after cesarean scar pregnancy management was 81.1% (30/37) among women who wished to conceive, with a live birth rate of 78.4% (29/37); 1 woman was in her third trimester of pregnancy at the time of analyses. The time between cesarean scar pregnancy management and subsequent ongoing pregnancy was 4 months (interquartile range, 3-6; P=.02) after expectant management, 18 months (interquartile range, 13-22) after initial methotrexate treatment, 5 months (interquartile range, 3-14; P=.01) after a curettage, and 6 months (interquartile range, 4-15; P=.03) after a laparoscopic niche resection.

CONCLUSION

Surgical treatment of a cesarean scar pregnancy led to a high success rate without additional interventions, high pregnancy rates with a short time interval between treatment, and subsequent pregnancy leading to an ongoing pregnancy or live birth. Conservative management, both with expectant management and methotrexate treatment, led to high (re)intervention rates. Different management approaches are indicated for different types of cesarean scar pregnancies.

Hysteroscopic treatment of Cesarean Scar Pregnancy: A systematic review

More than 30 regimens, medical and surgical, have been described for the treatment of Cesarean Scar Pregnancies (CSPs). This study aims to collect and analyze data in the published literature regarding the hysteroscopic management of CSPs focusing on efficacy and complications. Using a protocol registered with Prospero (#CRD42021242314), the electronic databases PubMed/Medline, Scopus, Clinical-Trials.gov and the Cochrane Library were comprehensively searched, from their inception to June 2020. Medical Subject Headings terms such as caesarean ectopic, hysteroscopy and endoscopy were used for the identification of the relevant records. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed to design the present systematic review. Eligible articles assessing the role of hysteroscopy in CSP were considered the studies published in peer-reviewed journals. Any studies with less than 10 cases or articles that insufficiently detailed the treatment regimen, the outcomes, and the success rate, were excluded. Selected articles were assessed for the level of evidence, based on Oxford Centre for Evidence-based Medicine guidelines. The methodologic quality, including the risk of bias, was evaluated with the employment of the Effective Public Health Practice Project Quality Assessment Tool. Ten out of 613 studies were included in the present review comprising 812 women with CSP treated by hysteroscopy. The treatment modalities were divided into three categories: (i) hysteroscopic resection of CSP, (ii) hysteroscopy after preoperative use of HIFU and (iii) preoperative use of UAE before hysteroscopic treatment. The overall success rate of hysteroscopic treatment on CSP cases was 91%, whereas the rate of hemorrhage or excessive vaginal bleeding (>500 mL) and the rate of hysterectomy were 1.66% and 0.28% respectively. According to the results of this systematic review, hysteroscopy appears to be a safe and effective procedure for CSP management. Current findings are primarily based on retrospective studies with poor methodological quality. Multicenter, well-designed studies are needed to draw definite conclusions.

The effect of ultrasound-guided high-intensity focused ultrasound treatment for cesarean scar pregnancy on ovarian reserve

OBJECTIVE

The aim of this study was to evaluate changes in anti-Müllerian hormone (AMH) levels after ultrasound-guided high-intensity focused ultrasound (USgHIFU) treatment of cesarean scar pregnancy (CSP).

METHODS

A retrospective case series study was conducted in the Affiliated Hospital of North Sichuan Medical College. Thirty-two women with cesarean scar pregnancy who met the inclusion criteria were enrolled in the study between January 2018 and December 2019. All patients underwent USgHIFU treatment with or without suction curettage. Intraoperative blood loss in suction curettage and hysteroscopy procedures, time to return of β-human chorionic gonadotropin (β-hCG) to normal levels, and time to recovery of normal menstruation were recorded. AMH levels before and 3 months after HIFU treatment were compared to determine whether USgHIFU treatment affected ovarian reserve.

RESULTS

AMH levels before and 3 months after HIFU ablation were 1.87 ± 1.19 ng/ml and 1.90 ± 1.17 ng/ml, respectively. There was no significant difference in AMH levels between the two-time points (p > .05). The median volume of intraoperative blood loss was 20 ml, the median time for the serum β-hCG level to return to normal was 35.5 days, and the median time of menstruation recovery was 39 days.

CONCLUSIONS

USgHIFU treatment for CSP was effective and safe without affecting ovarian reserve.

Approaches in the Treatment of Cesarean Scar Pregnancy and Risk Factors for Intraoperative Hemorrhage: A Retrospective Study

Background: Cesarean scar pregnancy (CSP) involves a rare form of placental attachment that often leads to life-threatening conditions. The best treatment for CSP has been debated for decades. We aimed to evaluate the different treatments for CSP and analyzed the risk factors for intraoperative hemorrhage.

Methods: CSP patients treated at the Affiliated Hospital of Jiangnan University were reviewed retrospectively from January 2014 to 2020. CSP was classified into three types based on the location and shape of gestational tissue, blood flow features, and thickness of the myometrium at the incision site. The clinical characteristics, types, approaches of treatment, and clinical outcomes of CSP were analyzed.

Results: A total of 55 patients were included in this study, 29 (52.7%) of whom underwent transvaginal curettage after uterine artery embolization (UAE) and 22 (40%) of whom underwent transabdominal ultrasound-guided hysteroscopic curettage (USHC) in type I and II. Four patients (7.3%) classified as type III underwent laparoscopic cesarean scar resection (LCSR). Intraoperative blood loss, blood transfusion rate, and scar diverticulum were significantly higher in type II than in type I (P < 0.05). Even though USHC showed no differences in intraoperative blood loss, length of stay, and scar diverticulum compared with curettage after UAE (P > 0.05), superiority was found in surgical time and hospitalization cost (P < 0.05). Furthermore, the type of CSP (OR = 10.53, 95% CI: 1.69–65.57; P = 0.012) and diameter of the gestational sac (OR = 25.76, 95% CI: 2.67–248.20; P = 0.005) were found to be risk factors for intraoperative hemorrhage.

Conclusions: Transabdominal ultrasound-guided hysteroscopic curettage is an effective and relatively safe treatment option for patients with CSP. Type of CSP and diameter of the gestational sac were found to be associated with excessive intraoperative hemorrhage.

MRI findings of complications related to previous uterine scars

Although the World Health Organization suggests 10–15% as the adequate cesarean delivery rate to assure optimal prognosis for mother and children, cesarean rates have continuously increased worldwide over the last three decades, even in primiparous women. Moreover, uterine scars after myomectomies, complications of obstetrical interventions and more recently, after fetal surgery, are often observed. This review article describes the most commonly seen complications related to prior uterine scars and discusses their imaging findings, with emphasis on the increasing role of Magnetic Resonance Imaging for diagnosis.

Long-term risks and benefits associated with cesarean delivery for mother, baby, and subsequent pregnancies: Systematic review and meta-analysis

BACKGROUND

Cesarean birth rates continue to rise worldwide with recent (2016) reported rates of 24.5% in Western Europe, 32% in North America, and 41% in South America. The objective of this systematic review is to describe the long-term risks and benefits of cesarean delivery for mother, baby, and subsequent pregnancies. The primary maternal outcome was pelvic floor dysfunction, the primary baby outcome was asthma, and the primary subsequent pregnancy outcome was perinatal death.

METHODS AND FINDINGS

Medline, Embase, Cochrane, and Cumulative Index to Nursing and Allied Health Literature (CINAHL) databases were systematically searched for published studies in human subjects (last search 25 May 2017), supplemented by manual searches. Included studies were randomized controlled trials (RCTs) and large (more than 1,000 participants) prospective cohort studies with greater than or equal to one-year follow-up comparing outcomes of women delivering by cesarean delivery and by vaginal delivery. Two assessors screened 30,327 abstracts. Studies were graded for risk of bias by two assessors using the Scottish Intercollegiate Guideline Network (SIGN) Methodology Checklist and the Risk of Bias Assessment tool for Non-Randomized Studies. Results were pooled in fixed effects meta-analyses or in random effects models when significant heterogeneity was present (I2 ≥ 40%). One RCT and 79 cohort studies (all from high income countries) were included, involving 29,928,274 participants. Compared to vaginal delivery, cesarean delivery was associated with decreased risk of urinary incontinence, odds ratio (OR) 0.56 (95% CI 0.47 to 0.66; n = 58,900; 8 studies) and pelvic organ prolapse (OR 0.29, 0.17 to 0.51; n = 39,208; 2 studies). Children delivered by cesarean delivery had increased risk of asthma up to the age of 12 years (OR 1.21, 1.11 to 1.32; n = 887,960; 13 studies) and obesity up to the age of 5 years (OR 1.59, 1.33 to 1.90; n = 64,113; 6 studies). Pregnancy after cesarean delivery was associated with increased risk of miscarriage (OR 1.17, 1.03 to 1.32; n = 151,412; 4 studies) and stillbirth (OR 1.27, 1.15 to 1.40; n = 703,562; 8 studies), but not perinatal mortality (OR 1.11, 0.89 to 1.39; n = 91,429; 2 studies). Pregnancy following cesarean delivery was associated with increased risk of placenta previa (OR 1.74, 1.62 to 1.87; n = 7,101,692; 10 studies), placenta accreta (OR 2.95, 1.32 to 6.60; n = 705,108; 3 studies), and placental abruption (OR 1.38, 1.27 to 1.49; n = 5,667,160; 6 studies). This is a comprehensive review adhering to a registered protocol, and guidelines for the Meta-analysis of Observational Studies in Epidemiology were followed, but it is based on predominantly observational data, and in some meta-analyses, between-study heterogeneity is high; therefore, causation cannot be inferred and the results should be interpreted with caution.

CONCLUSIONS

When compared with vaginal delivery, cesarean delivery is associated with a reduced rate of urinary incontinence and pelvic organ prolapse, but this should be weighed against the association with increased risks for fertility, future pregnancy, and long-term childhood outcomes. This information could be valuable in counselling women on mode of delivery.

Women's self-reported experience of unplanned caesarean section: Results of a Swedish study

BACKGROUND

women´s experience of emergency caesarean section is often described as less positive compared to a vaginal birth or a planned caesarean section. Midwifery care for women where deviations from a normal birth process are present is a challenge. The aim of study was to compare self-reported birth outcomes for women undergoing birth through spontaneous onset of labour between those who actually had a vaginal birth and those who eventually had an emergency caesarean section.

DESIGN AND SETTING

the study was part of a prospective longitudinal cohort study of parents' experiences, attitudes, and beliefs related to childbirth.

METHOD AND FINDINGS

questionnaires were answered by 870 women in midpregnancy, two months postpartum and one year after birth. 766 women (88%) had a vaginal birth, and 104 (12%) had an emergency caesarean section. The most common indications of emergency caesarean section were dystocia, foetal distress, and malpresentation. Women in the emergency caesarean group were more likely to be primiparous (59.6%) and have a body mass index > 30 (10.7%). Childbirth fear was twice as common among these women, and they were more likely to have preferred a caesarean delivery when asked about birth preference in the middle of pregnancy (OR 3.7, Cl 1.8-7.5). Induction of labour (OR 2.5, Cl 1.6-4.0), the use of oxytocin for augmentation (OR 1.9, Cl 1.3-2.9), and the use of epidural as pain relief during labour (OR 5.6, Cl 3.6-8.7) were more common among women having an emergency caesarean section. Transport of the new-born to a neonatal intensive care unit was three times as common. More than a third (37%) of the women in the caesarean group preferred a caesarean section in case of another birth. Childbirth fear was more common one year after birth with 32% of these women describing their fear as moderate or strong (OR 3.6, CI 2.1-6.0).

KEY CONCLUSIONS

women undergoing emergency caesarean section are more likely to experience fear and to have a negative birth experience. It is essential for the midwife to promote a sense of control, involve the woman in the procedure, and create security in a threatening situation. This is made possible in relationship characterized by mutuality, trust, on-going dialogue, shared responsibility, and enduring presence.

Analysis of ectopic pregnancies admitted to emergency department

Objectives

Ectopic pregnancy (EP) may cause significant morbidity and mortality. In this study, we aimed to evaluate the demographic characteristics, presence of risk factors and diagnostic parameters of the patient with EP and predicting parameters for ruptured EP.

Methods

Patients who presented to emergency department (ED) and diagnosed as EP within one year were included to the study. The demographic characteristics, β-human chorionic gonadotropin (β-HCG) levels, transvaginal ultrasonography (TVUSG) findings, treatment protocols, pathology reports and hemoglobin levels at the time of admission to ED were obtained from patient files and hospital automation system and statistical analysis was performed.

Results

Total 35 patients were included to the study. The mean age of the patients was 30 ± 5.6 years. Among the patients, 46% had a history of caesarean section (C-section). The complaints of the patients at presentation, their age, gestational week and the β-HCG levels were found to be inefficient in predicting ruptured EPs. TVUSG was found statistically significant in terms of demonstrating ruptures in EP. The ratio of salpingectomies was observed to be higher in the surgical treatment of ruptured EPs.

Conclusions

C-section was most frequently seen with EP. There is no absolute diagnostic parameter for predicting ruptured EPs and TVUSG may be a clue for diagnosis. The final diagnosis is made through surgery.

Cesarean scar pregnancy: a systematic review of treatment studies

OBJECTIVE

To study treatment modalities for cesarean scar pregnancies (CSPs), focusing on efficacy and complications in relation to study quality.

DESIGN

Systematic review.

SETTING

Not applicable.

PATIENT(S)

A total of 2,037 women with CSP.

INTERVENTION(S)

Review of MEDLINE, EMBASE, and Cochrane Library to find studies including five or more women. Data were extracted on primary treatment modality/efficacy, complications, and future fertility. The level of evidence was categorized according to Oxford Centre for Evidence-based Medicine guidelines. Quality was assessed using The Cochrane Collaboration's Risk of Bias Tools for Randomized Controlled Trials and the modified Delphi techniques for case series. Meta-analysis was impossible owing to multifarious treatments.

MAIN OUTCOME MEASURE(S)

Successful first-line treatment. Complications were hysterectomy, laparotomy, bleeding >1,000 mL, or blood transfusion.

RESULT(S)

Fifty-two studies were included: four randomized, controlled trials and 48 case series. Fifteen of the 52 analyzed studies were scored as high quality. Treatment modalities were condensed to 14 different approaches. Combining study quality, level of evidence, efficacy, and safety, five approaches for treating CSP are recommended, depending on availability, severity of patient symptoms, and surgical skills: [1] resection through a transvaginal approach, [2] laparoscopy, [3] uterine artery embolization in combination with dilatation and curettage and hysteroscopy, [4] uterine artery embolization in combination with dilatation and curettage, and [5] hysteroscopy.

CONCLUSION(S)

This review recommends treatment options for CSP in clinical practice, based on efficacy and safety. The literature supports an interventional rather than medical approach. Present recommendations are primarily based on case series. Multicenter, well-designed studies are needed to draw definite conclusions on how to treat CSP.

Cesarean Delivery and Risk for Subsequent Ectopic Pregnancy

OBJECTIVE

This study aims to examine the risk for subsequent ectopic pregnancy in women with prior cesarean delivery.

STUDY DESIGN

Women with a history of at least one cesarean delivery in the state of Utah during 1996 to 2011 were identified and compared with women with vaginal delivery only. The primary outcome was subsequent ectopic pregnancy. Data were analyzed by multivariate logistic regression and stratified by first, second, or third live births. Model covariates included maternal age, ethnicity, marital status, education level, gravidity, and prior ectopic pregnancy.

RESULTS

Overall, 260,249 women with at least one live birth were identified. After exclusions, 255,082, 154,930, and 70,228 women had at least one, two, and three prior live births that lead to 531, 199, and 62 subsequent ectopic pregnancies, respectively. Women who had one prior cesarean delivery were not at increased risk for subsequent ectopic pregnancy in relation to women with no prior cesarean delivery. However, women with two of two, two of three, or three of three prior cesareans had increased risk for subsequent ectopic pregnancy with odds ratios (95% confidence interval) of 1.54 (1.06-2.22), 3.50 (1.49-8.24), and 1.99 (1.00-3.98), respectively.

CONCLUSION

History of two or three cesarean deliveries is associated with increased risk for subsequent ectopic pregnancy.

Cesarean section and rate of subsequent stillbirth, miscarriage, and ectopic pregnancy: a Danish register-based cohort study

BACKGROUND

With cesarean section rates increasing worldwide, clarity regarding negative effects is essential. This study aimed to investigate the rate of subsequent stillbirth, miscarriage, and ectopic pregnancy following primary cesarean section, controlling for confounding by indication.

METHODS AND FINDINGS

We performed a population-based cohort study using Danish national registry data linking various registers. The cohort included primiparous women with a live birth between January 1, 1982, and December 31, 2010 (n = 832,996), with follow-up until the next event (stillbirth, miscarriage, or ectopic pregnancy) or censoring by live birth, death, emigration, or study end. Cox regression models for all types of cesarean sections, sub-group analyses by type of cesarean, and competing risks analyses for the causes of stillbirth were performed. An increased rate of stillbirth (hazard ratio [HR] 1.14, 95% CI 1.01, 1.28) was found in women with primary cesarean section compared to spontaneous vaginal delivery, giving a theoretical absolute risk increase (ARI) of 0.03% for stillbirth, and a number needed to harm (NNH) of 3,333 women. Analyses by type of cesarean section showed similarly increased rates for emergency (HR 1.15, 95% CI 1.01, 1.31) and elective cesarean (HR 1.11, 95% CI 0.91, 1.35), although not statistically significant in the latter case. An increased rate of ectopic pregnancy was found among women with primary cesarean overall (HR 1.09, 95% CI 1.04, 1.15) and by type (emergency cesarean, HR 1.09, 95% CI 1.03, 1.15, and elective cesarean, HR 1.12, 95% CI 1.03, 1.21), yielding an ARI of 0.1% and a NNH of 1,000 women for ectopic pregnancy. No increased rate of miscarriage was found among women with primary cesarean, with maternally requested cesarean section associated with a decreased rate of miscarriage (HR 0.72, 95% CI 0.60, 0.85). Limitations include incomplete data on maternal body mass index, maternal smoking, fertility treatment, causes of stillbirth, and maternally requested cesarean section, as well as lack of data on antepartum/intrapartum stillbirth and gestational age for stillbirth and miscarriage.

CONCLUSIONS

This study found that cesarean section is associated with a small increased rate of subsequent stillbirth and ectopic pregnancy. Underlying medical conditions, however, and confounding by indication for the primary cesarean delivery account for at least part of this increased rate. These findings will assist women and health-care providers to reach more informed decisions regarding mode of delivery. Please see later in the article for the Editors' Summary.