Does a Caesarean section increase the time to a second live birth? A register-based cohort study

Prevalence and risk factor of postoperative adhesions following repeated cesarean section: A prospective cohort study

OBJECTIVE

To evaluate the prevalence of intraperitoneal adhesions after repeated cesarean delivery and its associated personal and surgical risk factors.

METHODS

This prospective cohort study was conducted at the delivery ward at Fayoum University Hospital from October 2020 to December 2021. Women were recruited according to predetermined inclusion and exclusion criteria. Eligible women were interviewed, and data were obtained for personal history, past surgical and obstetrical history, and data about the current delivery. Nair's scoring system was used to evaluate intraperitoneal adhesions. Postoperative data and complications were reported.

RESULTS

Three hundred women were recruited. Moderate to severe adhesions occurred in 186 patients (62%). These patients had a significantly prolonged hospital stay and were delivered by expert surgeons (P < 0.001 and P = 0.008, respectively). The adhesion score correlated positively with patients' age (P < 0.001), parity (P < 0.001), interpregnancy interval (P = 0.033), duration of hospital admission either previously or in the current delivery (P = 0.001 and P < 0.001), time to ambulation (P < 0.001), time to intestinal movement (P < 0.001), operative time (P < 0.001), and surgeons' age and experience (both P = 0.015).

CONCLUSION

Adhesions led to increased maternal morbidity. Multiple contributing factors were significantly related to adhesions with multiple cesarean deliveries.

Caesarean deliveries, subsequent reproductive behaviour and children ever born in India

Against the backdrop of the alarming rise in Caesarean section (C-section) births in India, this study aimed to examine the association between C-section births, fertility decline and female sterilization in the country. A cross-sectional design was used to investigate the association between C-section delivery and subsequent reproductive behaviour in women in India. Data were from the National Family Health Survey (NFHS-4). The study sample comprised 255,726 currently married women in the age group of 15-49 years. The results showed a strong positive relationship between C-section births and female sterilization. The predicted probabilities (PP) from the multivariate regression model indicated a higher chance of female sterilization in women with C-section births (PP = 0.39, p<0.01) compared with those with non-C-section births (PP = 0.20, p<0.01). Both state-level correlation plots and Poisson regression estimates showed a strong negative relationship between C-section births and mean children ever born (CEB). Based on the results, it may be concluded that the use of C-sections and sterilization were strongly correlated in India at the time of the NFHS-4, thus together contributing to fertility decline. A strong negative association was found between the occurrence of C-sections and CEB. The increased and undesired use of C-section births and consequent female sterilization is a regressive socio-demographic process that often violates women's rights. Fertility decline should happen through informed choice of family planning and must protect the reproductive rights of women.

Intra-cavitary fluid resulted from caesarean section but not isthmocele compromised clinical pregnancy after IVF/ICSI treatment

The aim of this study was to explore whether the presence of intra-cavitary fluid (ICF) influences the pregnancy outcomes of patients with caesarean section (CS) in embryo transfer cycles. A total of 8494 transferred cycles of 4924 women were enrolled in this retrospective study and separated into three subgroups by previous delivery method and the presence of intra-cavity fluid, a caesarean group with ICF (CS-ICF, n = 649), a caesarean group without ICF (CS-noICF, n = 3207), and the remaining 4638 cycles without ICF were included in the vaginal delivered group (VD, n = 4638). Baseline characteristics and clinical outcome were compared. Propensity score matching (PSM) was conducted to adjust confounding factors between groups. Patients in the CS-ICF group were of younger age (36.49 ± 4.19 vs 37.34 ± 4.25, 37.32 ± 4.86, P < 0.001), had better ovary reserve, and had more blastocyst transferred compared with the CS-noICF and VD groups. However, cycles in the CS-ICF group achieved unsatisfactory clinical pregnancy outcomes. PSM analysis for comparability and differences in clinical outcomes still existed. The clinical pregnancy rate was significantly lower in the CS-ICF group than in the CS-noICF group (35.1% vs 41.7% for CS-noICF group, 48.1% for VD group, P < 0.001). Subgroup analysis of fresh embryo transferred cycles, the differences in clinical outcomes disappeared after PSM analysis, while the clinical pregnancy rate was still lowest among the three matched groups of FET cycles (36.4% vs 50.3% for VD group, P < 0.001). The presence of intra-cavitary fluid (ICF), but not necessarily the isthmocele, significantly compromises the clinical pregnancy rate in patients with previous CS undergoing IVF/ICSI treatment.

Reproductive and pregnancy outcomes following embryo transfer in women with previous cesarean section: A systematic review and meta-analysis

INTRODUCTION

Cesarean section affects subsequent spontaneous pregnancies because of implantation issues. However, its impact on post-embryo transfer pregnancies is still debated. This review aimed to evaluate the impact of a previous cesarean section on fertility and pregnancy outcomes of women undergoing fresh or frozen embryo transfer.

MATERIAL AND METHODS

MEDLINE, Scopus, ClinicalTrials.gov, Scielo, EMBASE, Cochrane Library at the CENTRAL, and LILACS were searched from inception to February 2021. Studies were included if they evaluated reproductive or pregnancy outcomes after fresh or frozen embryo transfer in infertile women with a previous cesarean section relative to women with a previous vaginal delivery. Random-effect meta-analyses to calculate risk ratio (RR) or mean differences with 95% confidence intervals (CI) followed by subgroup analysis for fresh and frozen embryo transfer were performed. Risk of bias and quality assessment were conducted using Newcastle-Ottawa scale and GRADE criteria. The review was registered in the International Prospective Register of Systematic Reviews (CRD42021226297).

RESULTS

Ten studies, with data provided for 13 696 participants, were eligible. For embryo transfers after cesarean section, compared with vaginal delivery, there was a significant reduction of the live birth rate (RR 0.88, 95% CI 0.79-0.99) and biochemical pregnancy rate (RR 0.89, 95% CI 0.82-0.96). No statistically significant differences were found for clinical pregnancy rate (RR 0.92, 95% CI 0.84-1.02), ectopic pregnancies (RR 1.00, 95% CI 0.68-1.46), pregnancy loss (RR 1.05, 95% CI 0.94-1.18), multiple pregnancies (RR 0.80, 95% CI 0.63-1.02), stillbirths (RR 0.86, 95% CI 0.27-2.69), birth defects (RR 1.71, 95% CI 0.49-5.96) or birthweight (mean difference 46.82, 95% CI -40.16 to 133.80). Subgroup analysis revealed an increased risk for preterm birth in post-cesarean section fresh embryo transfer pregnancies (RR 1.59, 95% CI 1.16-2.19).

CONCLUSIONS

Low-grade evidence shows that post-embryo transfer pregnancies in infertile women who had a previous cesarean delivery result in reduced biochemical pregnancy and live birth rates relative to women with a previous vaginal delivery. An increased risk for preterm birth is notable in post-fresh embryo transfer pregnancies.

Impact of previous Caesarean section on reproductive outcomes after assisted reproductive technology: systematic review and meta-analyses

This meta-analysis investigated whether a previous Caesarean section has an impact on the outcomes of treatment with assisted reproductive technology (ART). PubMed, Embase, Cochrane Library, Web of Science and Google Scholar were searched. Clinical trials published in English up to May 2020 were included. Seven studies performed between 2016 and 2020 met all the inclusion criteria. It was found that previous Caesarean section leads to significantly decreased clinical pregnancy rate (CPR) (risk ratio [RR] 0.86; 95% confidence interval [CI], 0.81, 0.92; P < 0.00001) and live birth rate (LBR) (RR 0.80; 95% CI 0.73, 0.86; P < 0.00001). Caesarean section increased the miscarriage rate (RR 1.39; 95% CI 1.18, 1.64; P < 0.0001), and difficult transfer (RR 8.23; 95% CI 4.63, 14.65; P < 0.00001) after ART compared with women who had previous vaginal delivery. The combined results also showed similar endometrial thickness, number of oocytes retrieved, implantation rate, ectopic pregnancy rate, preterm birth and stillbirth between women with previous Caesarean section and women with previous vaginal delivery. In conclusion, Caesarean sections have a detrimental effect on CPR and LBR, and increase the risk of miscarriage and difficult transfer. The indications for Caesarean section should be strictly controlled, and full consultation should be provided to pregnant women. Further studies with stratification analysis of twin and single pregnancies are needed to evaluate the impact of Caesarean section.

Association Between Mode of First Delivery and Subsequent Fecundity and Fertility

IMPORTANCE

More than 20% of births globally are by cesarean delivery, including more than 30% in the US. Prior studies have reported lower rates of childbearing after cesarean delivery, but it is not clear if this is due to maternal choice or lower conception rates.

OBJECTIVE

To investigate the association between mode of first delivery and subsequent conceptions and live births.

DESIGN, SETTING, AND PARTICIPANTS

The First Baby Study was a multicenter prospective cohort study of women aged 18 to 35 years with singleton pregnancies, enrolled and interviewed before first childbirth, who delivered in Pennsylvania from 2009 to 2011 and were followed up for 36 months after delivery (until April 2014). Data analysis for this study took place between May and July 2019 and in January 2020.

EXPOSURES

Mode of first delivery (cesarean or vaginal).

MAIN OUTCOMES AND MEASURES

Rates of subsequent conceptions and live births. Discrete-time Cox proportional hazard regression models were used to compare the rate of subsequent conception (vaginal vs cesarean) among those who completed the 36-month survey, accounting for reported months of unprotected intercourse during the follow-up period and adjusting for relevant covariates. A log binomial regression was used to compare the age-adjusted rate of subsequent live birth (vaginal vs cesarean) among those who completed the 36-month survey.

RESULTS

The study population consisted of 2423 women who were retained to the 36-month survey (mean [SD] age at baseline was 27.2 [4.4] years and 712 [29.4%] delivered by cesarean). There were 2046 women who had unprotected intercourse during the follow-up period, 2021 of whom provided data on months of unprotected intercourse. Cesarean delivery was associated with lower rates of conception after unprotected intercourse during the follow-up period (413 of 599 [68.9%]) compared with vaginal delivery (1090 of 1422 [76.7%]) (adjusted hazard ratio, 0.85; 95% CI, 0.74-0.96). Cesarean delivery was also associated with reduced likelihood of a subsequent live birth (305 women [42.8%]) compared with vaginal delivery (857 women [50.1%]), with an age-adjusted risk ratio of 0.83 (95% CI, 0.75-0.92).

CONCLUSIONS AND RELEVANCE

In the 3 years following first childbirth, women who delivered their first child by cesarean had lower rates of conception after unprotected intercourse, and fewer of these women had a second child than those who delivered vaginally.

Non spontaneous vaginal delivery was associated with lower probability of subsequent fertility

OBJECTIVE

Previous systematic reviews have reported that cesarean birth is associated with reduced rate of subsequent fertility. However, other common mode of delivery was poorly understood. The aim of this study was to systematically investigate the subsequent fertility in patients having different modes of non-spontaneous vaginal delivery, if compared to normal vaginal delivery.

STUDY DESIGNS

Medline (via PubMed), Web of Science, Embase (via Dialog), CENTRAL (via Cochrane Library), ScienceDirect (via Elsevier) and ClinicalTrial.gov were searched up to October 2019, without language restrictions in this systematic review and meta-analysis. Articles assessing the mode of delivery and subsequent fertility were included. Quality assessment was evaluated using the nine-point Newcastle Ottawa Scale by two independent reviewers.

RESULTS

Twenty-one articles, including 4,423,544 women of reproductive age, were included. Results showed that women had a 9% (RR: 0.91 [95 %CI 0.88, 0.94]) lower probability of subsequent fertility in primary cesarean birth group, compared with spontaneous vaginal delivery. Further analysis discovered that a 13 % (0.87, [0.85, 0.90]) lower probability of subsequent fertility was observed in women delivered by emergency cesarean birth, a 14 % (0.86, [0.82, 0.91) lower probability by elective cesarean birth, a 39 % (0.61, [0.57, 0.66]) by maternal-requested cesarean birth, and a 2% (0.98, [0.97, 1.00]) by instrumental vaginal delivery.

CONCLUSIONS

Non-spontaneous vaginal delivery may be associated with lower probability of subsequent fertility. Decision makers and obstetricians should be cautious when choosing the mode of delivery.

Risk of having one lifetime pregnancy and modification by outcome of pregnancy and perinatal loss

INTRODUCTION

With increasing cesarean section rates, adverse pregnancy outcomes such as preterm delivery and small-for-gestational-age continue to be public health challenges. Besides having high co-occurrence and interrelation, it is suggested that these outcomes, along with preeclampsia, are associated with reduced subsequent fertility. On the other hand, the loss of a child during the perinatal period is associated with increased reproduction. Failure to consider this factor when estimating the effects of pregnancy outcomes on future reproduction may lead to erroneous conclusions. However, few studies have explored to what degree a perinatal loss contributes to having a next pregnancy in various adverse pregnancy outcomes.

MATERIAL AND METHODS

This was a population-based study of mothers giving birth to their first singleton infant (≥22 gestational weeks) during 1967-2007 who were followed for the occurrence of a second birth in the Medical Birth Registry of Norway until 2014. Relative risks with 95% confidence intervals for having one lifetime pregnancy by preterm delivery, small-for-gestational-age, preeclampsia and cesarean section were obtained by generalized linear models for the binary family and adjusted for maternal age at first birth, education and year of first childbirth. Main outcome measure was having one lifetime pregnancy.

RESULTS

Nearly 900 000 women gave birth to their first singleton infant in 1967-2007, of which 16% had only one lifetime pregnancy. These women were older at first delivery, had less education and there was a higher proportion of unmarried women than women with two or more births. In women with pregnancy complications where the infant survived the perinatal period, there were the following relative risks for one lifetime pregnancy: increased preterm delivery: 1.21 (1.19-1.22)], small-for-gestational-age: 1.13 (1.12-1.15), preeclampsia: 1.09 (1.07-1.11), cesarean section: 1.24 (1.23-1.25). The risk was significantly reduced if the child was lost (preterm delivery: 0.63 [0.59-0.68], small-for-gestational-age: 0.57 [0.51-0.63], preeclampsia: 0.69 [0.59-0.80], cesarean section: 0.67 [0.56-0.79]), compared with women with no perinatal loss and no adverse outcome.

CONCLUSIONS

The associations between adverse outcomes of pregnancy and the risk of having one lifetime pregnancy were strongly modified by child survival in the perinatal period.

Incidence and sites of pelvic adhesions in women with post-caesarean infertility

This cross-sectional study was designed to evaluate the incidences and sites of pelvic adhesions in women with post-caesarean unexplained infertility. This study was conducted at the Tanta University Hospitals in the period from August 1 2015 to July 31 2016. The enrolled patients were assessed by a diagnostic laparoscopy for the presence and sites of abdominal and pelvic adhesions. Pelvic adhesions were found in 98 cases (73.13%) and the remaining 36 cases (26.87%) were free of adhesions. Adhesions were tubal in 55.10%, ovarian in 20.40%, combined tubo-ovarian and omental adhesions in 11.22%, uterine adhesions in 6.12% and a frozen pelvis was found in 7.14%. There was no correlation between the severity of the adhesions and the number of previous caesarean sections (CS). The data of this study led us to conclude that pelvic adhesions are common in patients with unexplained infertility following a caesarean delivery. Tubal and ovarian adhesions to the lateral pelvic wall represent a pathognomonic feature in post-caesarean infertility. Impact Statement What is already known on this subject? Adhesions following a caesarean delivery have been assessed by many studies at the time of the next caesarean delivery. These adhesions have not been studied well in the patients with unexplained infertility. What the results of this study add? The results of this study specify the incidences and the sites of the adhesions which are considered to be pathognomonic for caesarean section. What the implications are of these findings for clinical practice and/or further research? These findings should be applied when the cases of post-caesarean infertility are evaluated in order to shorten the duration and burdens of infertility.

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.

Biomechanics of the human uterus

The appropriate biomechanical function of the uterus is required for the execution of human reproduction. These functions range from aiding the transport of the embryo to the implantation site, to remodeling its tissue walls to host the placenta, to protecting the fetus during gestation, to contracting forcefully for a safe parturition and postpartum, to remodeling back to its nonpregnant condition to renew the cycle of menstruation. To serve these remarkably diverse functions, the uterus is optimally geared with evolving and contractile muscle and tissue layers that are cued by chemical, hormonal, electrical, and mechanical signals. The relationship between these highly active biological signaling mechanisms and uterine biomechanical function is not completely understood for normal reproductive processes and pathological conditions such as adenomyosis, endometriosis, infertility and preterm labor. Animal studies have illuminated the rich structural function of the uterus, particularly in pregnancy. In humans, medical imaging techniques in ultrasound and magnetic resonance have been combined with computational engineering techniques to characterize the uterus in vivo, and advanced experimental techniques have explored uterine function using ex vivo tissue samples. The collective evidence presented in this review gives an overall perspective on uterine biomechanics related to both its nonpregnant and pregnant function, highlighting open research topics in the field. Additionally, uterine disease and infertility are discussed in the context of tissue injury and repair processes and the role of computational modeling in uncovering etiologies of disease. WIREs Syst Biol Med 2017, 9:e1388. doi: 10.1002/wsbm.1388 For further resources related to this article, please visit the WIREs website.

Objective Analysis of Vaginal Ultrasound Video Clips for Exploring Uterine Peristalsis Post Vaginal and Cesarean Section Deliveries

The nonpregnant uterus is characterized by cyclic contractions that assist in sperm transport to the fallopian tube, embryo transport to implantation site, and expulsion of menstrual debris. The effect of post-Cesarean section (CS) scar on uterine peristalsis is unclear, while worldwide the prevalence of CS deliveries is increasing. In this study, we developed a new objective method for analysis of dynamic characteristics of the nonpregnant uterus from transvaginal ultrasound (TVUS) recordings when the uterine cavity is not clearly observed, as may be the case in post-CS uteri. The method of active contours was utilized to detect the contours of the endometrium-myometrium interface (EMI) from sagittal cross-section TVUS images of nonpregnant uteri. The contours were straightened along the uterus centerline and registered with respect to the fundal end in order to reduce the noise due to movements of the physician and the participant. A dynamic analysis was conducted on these time-dependent contours in order to explore the frequency and amplitude of the EMI motility. The analysis was conducted on TVUS video clips from 12 nonpregnant participants, 7 post-CS and 5 controls. The frequencies of the EMI motility was 0.010 to 0.064 Hz at days 8 to 17 in the control participants and 0.014 to 0.073 Hz at days 9 to 15 in post-CS participants. The maximal amplitude of motility was 0.67 to 2.00 mm and 0.48 to 2.58 mm for the control and post-CS participants, respectively. In this preliminary study, we have not observed significant difference between the EMI motility of healthy and post-CS uteri.

Assessment of the uterus with three-dimensional ultrasound in women undergoing ART

BACKGROUND

A detailed assessment of the uterus forms a pivotal part of the ART treatment process. The emergence of three-dimensional ultrasound (3D US) has provided clinicians with a highly powerful tool in this respect. Assessments with 3D US range from the reconstruction of anatomical planes elusive to conventional US, to the objective measurement of anatomical volumes and vascularization parameters. However, despite the ever increasing number of publications emerging in the literature, the question of which aspects of 3D US are of most clinical value remains a topic of debate.

OBJECTIVE AND RATIONALE

The objective of this review is to dissect which aspects of the 3D US assessment of the uterus are supported by a strong level of evidence to date, and should therefore be incorporated into current routine clinical practice.

SEARCH METHODS

We conducted a systematic search of the PubMed database up to May 2016, using a combination of text words and Medical Subject Headings (MeSH) pertaining to the 3D US assessment of the uterus. All articles published in the English language were screened to ascertain relevance to women of reproductive age; further citations were retrieved through manual reference list searching.

OUTCOMES

A multitude of predominantly observational studies were identified, which concerned a vast variety of 3D US uterine assessments. All articles unequivocally praised the non-invasive, cost-effective, highly acceptable and objective nature of 3D US. Studies regarding the value of assessing the endometrial volume and vascularization prior to embryo transfer appeared conflicting and inconsistent. Studies regarding the imaging of uterine pathology and identification of intratubal and intrauterine devices consistently reported high rates of diagnostic accuracy. A recent RCT did not show an improvement in clinical outcomes when comparing 3D versus 2D US during embryo transfer. However, preliminary studies suggested that 3D US is superior in determining the site of implantation, particularly in ambiguous cases such as interstitial and angular pregnancies. Finally, pilot studies have suggested that the further integration of 3D and possibly 4D US with surgical interventions of the uterus may be a promising prospect.

WIDER IMPLICATIONS

3D US may prove to be an invaluable tool in the assessment of the uterus within the context of ART. Currently, the aim should be to highlight the aspects of 3D US that are most evidence-based and valuable for patients, and to incorporate these into routine clinical practice.

Brief Report: Cesarean Delivery and Subsequent Fecundability

BACKGROUND

Studies have shown that cesarean delivery is associated with fewer subsequent births relative to vaginal delivery, but it is unclear whether confounding by pregnancy intention or indication for surgery explained these results. We evaluated the association between cesarean delivery and subsequent fecundability among 910 primiparous women after singleton live birth.

METHODS

In a cohort of Danish women planning pregnancy (2007-2012), obstetrical history was obtained via registry linkage; time-to-pregnancy and covariate data were collected via questionnaire. Fecundability ratios (FRs) and 95% confidence intervals (CIs) were adjusted for potential confounders.

RESULTS

Relative to spontaneous vaginal delivery, emergency cesarean delivery with cephalic presentation showed little association with fecundability (FR = 1.0, 95% CI = 0.83, 1.3), but cesarean delivery with breech presentation (FR = 0.72, 95% CI = 0.53, 0.97) and planned cesarean delivery with cephalic presentation (FR = 0.51, 95% CI = 0.25, 1.0) were associated with reduced fecundability.

CONCLUSIONS

The cesarean-fecundability association varied by previous fetal presentation and emergency status.

The impact of obstetric mode of delivery on childhood behavior

PURPOSE

We investigated the hypothesis that mode of delivery affects childhood behavior and motor development and examined whether there are sex-specific associations, i.e., whether males and females have different risk estimates.

METHODS

Families with infants born between December 2007 and May 2008 (N = 11,134) were randomly selected and recruited to the Growing Up in Ireland study. Mode of delivery was classified into spontaneous vaginal delivery; instrumental vaginal delivery; emergency Cesarean section (CS); and elective CS. The 'Ages and Stages Questionnaire' was completed at age 9-months and the 'Strengths and Difficulties Questionnaire' at 3 years. Data were weighted to represent the national sample (N = 73,662) and multivariate logistic regression was used for the statistical analyses.

RESULTS

At age 9 months, elective CS was associated with a delay in personal social skills [adjusted odds ratio, aOR 1.24; (95% confidence interval, CI 1.04, 1.48)] and gross motor function [aOR 1.62, (95% CI 1.34, 1.96)], whereas emergency CS was associated with delayed gross motor function [aOR 1.30, (95% CI 1.06, 1.59)]. At age 3 years there was no significantly increased risk of an abnormal total SDQ score across all modes of delivery.

CONCLUSIONS

Children born by elective CS may face a delay in cognitive and motor development at age 9 months. No increase in total SDQ score was found across all modes of delivery. Further investigation is needed to replicate these findings in other populations and explore the potential biological mechanisms.

Time to subsequent live birth according to mode of delivery in the first birth

OBJECTIVE

To estimate the rate and time to next live birth by mode of delivery.

DESIGN

Hospital-based cohort.

SETTING

Aarhus University Hospital (AUH), Denmark.

POPULATION

All pregnant women attending AUH were invited to enroll in the Aarhus Birth Cohort (ABC) study between 1989 and 2010 (n = 91,625).

METHODS

Women were followed from their first live birth until the subsequent live birth or until censoring due to study end using Cox regression models.

MAIN OUTCOME MEASURES

Rate and time to subsequent live birth according to mode of delivery.

RESULTS

46,162 index live births were identified, of which 22,462 (49%) had a subsequent live birth. Women with any type of caesarean had a 6% reduction in the rate of subsequent live birth (HR 0.94, 95% CI 0.89, 0.98), which remained unchanged in the analysis by type (emergency, HR 0.95, 95% CI 0.89, 1.02; elective, HR 0.91, 95% CI 0.85, 0.98) compared with women who had a spontaneous vaginal delivery (SVD). Operative vaginal delivery was associated with an 8% reduction in subsequent live birth rates (HR 0.92, 95% CI 0.86, 0.98) and vaginal delivery complicated by shoulder dystocia with a 19% reduction compared with SVD. Median time to next birth in days was shortest in women with a first caesarean (994 days, 95% CI 973, 1026) and longest in women with a vaginal delivery complicated by shoulder dystocia (1065 days, 95% CI 994, 1191). In women with planned pregnancies, the shortest median time to second birth was in women with breech vaginal deliveries (859 days, 95% CI 737, 1089) and the longest in women with vaginal deliveries complicated by shoulder dystocia (1193 days, 95% CI 1028, 1430).

CONCLUSION

The impact of mode of delivery on subsequent rate and time to next birth was minimal in this study. The greatest reduction was among women with assisted vaginal delivery complicated by shoulder dystocia. This study is strengthened by data on pregnancy planning as well as information on complications of pregnancy, delivery and neonatal morbidities, all of which may influence a woman's decision on subsequent birth.