Gum chewing and gastrointestinal function following caesarean delivery: a systematic review and meta-analysis

AIMS AND OBJECTIVES

The aims of this systematic review and meta-analysis were to summarise current knowledge regarding gum chewing intervention for activation of the gastrointestinal (GI) system following caesarean delivery.

BACKGROUND

GI symptoms such as nausea, vomiting and defecatory difficulties are bothersome for women following a caesarean delivery. There is category A recommendation to not withhold oral intake postoperatively. However, current practice guidelines vary widely on time to initiate oral feeding post caesarean delivery, and additional research is needed. Gum chewing has been shown to stimulate the GI system in other postoperative patient populations.

DESIGN

A systematic review and meta-analysis.

METHODS

An electronic review was undertaken using the following resources: PubMed (Medline), CINAHL, EMBASE and ClinicalTrials.gov databases. Key words used in various combinations included cesarean section; cesarean delivery; postoperative chewing gum; bowel movement; bowel function and complications.

RESULTS

A total of 171 articles were found of which 166 were excluded: 157 were duplicates and the remainder did not meet the inclusion criteria. Five randomised control trials were included in the meta-analysis, focusing on gum chewing as an intervention as compared with a nongum chewing intervention, with a total of 846 participants. Compared with the nongum chewing group, gum chewing showed a beneficial impact on the major outcomes of digestive system activation, including bowel sound, gas passage and defecation.

CONCLUSIONS

This meta-analysis supports the effectiveness of gum chewing post caesarean delivery as a noninvasive/nonpharmacological intervention for reactivation of bowel movement.

RELEVANCE TO CLINICAL PRACTICE

Gum chewing in the immediate postoperative period following caesarean delivery may provide a socially acceptable, low-cost and safe intervention to reduce postcaesarean delivery GI complications and restore GI function.

Fetal laceration during caesarean section and its medico-legal sequelae

Fetal laceration is a recognized complication of caesarean delivery. The aim of this study was to investigate the incidence, type, location, risk factors and long-term consequences of accidental fetal incised wounds during caesarean delivery. During a five-year period, we observed 25 cases of fetal lacerations caused by the scalpel during hysterotomy. In 20 of these cases, we observed these lesions as consultants for the Neonatologic Care Unit; the other five cases came under our care after an insurance claim for damages against the gynaecologist. All the infants had a lesion located to the head. In only 5 of the 25 cases the lesion was reported in the operative summary, and only 16 of the 25 mothers had signed an informed consent before surgery. With regard to the 20 cases diagnosed at the Neonatologic Care Unit, the lesion was closed using single stitches in nine cases, and with biological glue in 11 cases. Concerning the five cases that underwent legal proceedings against the gynaecologist, a clinical examination was performed by an expert in Public Health and Social Security in collaboration with a paediatric surgeon to evaluate the degree of biological damage. In all five cases, the result of the legal challenge was monetary compensation for the physical and moral damage caused by the gynaecologists to the patients and their parents. Accidental fetal lesions may occur during caesarean delivery; the incidence is significantly higher during emergency caesarean delivery compared to elective procedures. Patients should sign an informed consent in which they should be informed about the risk of the occurrence of fetal lacerations during caesarean delivery in order to avoid legal complications.

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.

Update on volume therapy in obstetrics

Symptomatic hypotension (maternal nausea, vomiting, dizziness and dyspnoea) during spinal anaesthesia for caesarean delivery remains a prevalent clinical problem. Severe and sustained hypotension can lead to impairment of uteroplacental perfusion, foetal hypoxia, acidosis, neonatal depression and further adverse maternal outcomes of unconsciousness, pulmonary aspiration, apnoea and cardiac arrest. Mechanical methods aimed at countering the effects of aortocaval compression do not reliably prevent maternal hypotension. Intravenous crystalloid preloading (given prior to administration of spinal anaesthesia) has poor efficacy, and focus has changed towards decreased use of crystalloid preload and ephedrine, to increased use of coload (given at the time of spinal administration) with colloids or crystalloids, and early use of phenylephrine. The recent multicentre, randomised, double-blinded CAESAR trial demonstrated the efficacy of a mixed 500 ml 6% hydroxyethyl starch (HES) 130/0.4 + 500 ml Ringer's lactate (RL) preload in significantly reducing hypotension, compared to a 1-l RL preload, without adverse effects on coagulation and neonatal outcomes in healthy parturients undergoing caesarean delivery under spinal anaesthesia.

Epidural analgesia in labour and risk of caesarean delivery

BACKGROUND

A Cochrane Systematic Review of randomised controlled trials of epidural analgesia compared with other or no analgesia in labour reported no overall increased risk of caesarean delivery. However, many trials were affected by substantial non-compliance, and there are concerns about the external validity of some trials for contemporary maternity populations. We aimed to explore the association between epidural analgesia in labour and caesarean delivery in clinical practice and compare with findings from randomised controlled trials.

METHODS

Population-based cohort of pregnant women (n = 210 708) without major obstetrical complications who delivered a singleton live infant in hospitals in New South Wales, Australia, 2007-10. Data were obtained from linked, validated population-based data collections. Propensity score matching was used to examine the association between epidural analgesia in labour and caesarean delivery.

RESULTS

Epidural analgesia in labour was used by a third (31.5%, n = 66 317) of the women, and 9.8% (n = 20 531) had a caesarean delivery. Epidural analgesia in labour was associated with increased risk of caesarean delivery {risk ratio [RR] 2.5, [95% confidence interval (CI) 2.5, 2.6]}. The association with epidural analgesia in labour was higher for caesarean delivery for failure to progress {RR 3.0, [95% CI 2.9, 3.0]} than for caesarean delivery for fetal distress {RR 1.9, [95% CI 1.8, 2.0]}.

CONCLUSIONS

Epidural analgesia in labour is associated with caesarean delivery in a large maternity population. Population-based studies contribute important data about obstetrical care, when research settings and participants may not represent the clinical settings or broader population in which obstetrical interventions in labour are applied.

Caesarean delivery, caesarean delivery on maternal request and childhood overweight: a Chinese birth cohort study of 181 380 children

What is already known about this subject Both rates of caesarean section and childhood overweight have been steadily increasing over the past decade in many parts of the world. Caesarean delivery on maternal request contributes remarkably to the rising trend of caesarean births. A few small-scale studies suggest that caesarean section may be associated with later overweight and obesity, whereas little is known about the impact of caesarean delivery on maternal request. What this study adds Caesarean section is associated with an increased risk of childhood overweight. Children born by caesarean delivery on maternal request are also more likely to be overweight. The strength of the caesarean-overweight association is modest.

OBJECTIVES

To assess the impact of caesarean delivery including non-medically indicated maternal request caesarean delivery on childhood overweight.

METHODS

We conducted a prospective investigation of a Chinese birth cohort involving 181 380 children, who were born during 1993-1996 to mothers registered in a perinatal care surveillance system and whose weight and height were measured in 2000. Information on delivery mode and covariates was obtained from the surveillance system. Overweight was defined according to the International Obesity Task Force body mass index (BMI) cutoffs. Multivariable logistic regression was used to estimate adjusted odds ratios. Stratified analyses were done to test whether the association between caesarean section and overweight persisted across subgroups.

RESULTS

The adjusted odds ratio of overweight for children born by caesarean compared with vaginal delivery was 1.13 [95% confidence interval {CI}: 1.08, 1.18]. The association persisted in subgroups stratified by gender, maternal education, maternal BMI, weight gain during pregnancy and child birthweight (all P values for interaction test ≥0.30). The adjusted odds ratio of overweight for children born by non-medically indicated caesarean delivery compared with vaginal delivery was 1.18 (95% CI: 1.00, 1.41).

CONCLUSION

Caesarean delivery including non-medically indicated maternal request caesarean delivery compared with vaginal delivery modestly increases childhood overweight risk.

Mothers' expectations and other factors affecting breastfeeding at six months in Greece

The objective of this study is to determine the factors influencing breastfeeding duration in Greece. A total of 145 women were interviewed, on the third day post-partum. Women were followed up by telephone interviews at three and six months post-partum. Chi-square test and binomial sequential logistic regression analysis were used for statistical analysis. Results from this study show that baby-friendly hospital, antenatal courses, mother's perception of her capability to successfully breastfeed her infant, mother's intention to breastfeed for a duration of six months or more, mother's and father's education level, introduction of complementary foods or fluids, caesarean delivery, smoking and ethnicity were significantly associated with the duration of breastfeeding. In conclusion, additional antenatal and postnatal framework is necessary. Mothers' prediction of the duration of breastfeeding is an additional tool for identification of women with a high probability for early weaning.

Obstetrical interventions for term first deliveries in the US

BACKGROUND

Labour induction and caesarean are increasingly done without clinical indication. However, little is known about the prevalence of such interventions, or the characteristics of women who receive them. We used the 2003 revision of the US birth certificates to summarise recorded interventions and to characterise maternal profiles associated with such interventions.

METHODS

We carried out a retrospective study of 2.35 million primiparous women delivering singleton live births at 37-44 weeks in the US from 2005 to 2008. We used the 2003 revision of the birth certificate to define delivery categories: 'indicated' were those with induced labour or pre-labour caesarean for hypertension, diabetes, chorioamnionitis, failed cephalic version at ≥40 weeks, growth restriction (<3rd centile), or post-term (≥42 weeks); those with pre-labour caesarean with breech at ≥39 weeks; or those with caesarean with labour lasting ≥12 h, failed trial of labour, vacuum/forceps extraction, or fetal intolerance to labour. Remaining deliveries with induction/caesarean were classified as 'non-indicated' and all other deliveries 'spontaneous'.

RESULTS

Half of all term first births (50%) were delivered after intervention, and half of interventions were non-indicated (26% of all deliveries). Women with interventions were more likely to deliver on a weekday. Non-indicated interventions were more common among socially advantaged women.

CONCLUSIONS

Nearly a quarter of US term first deliveries had an indicated intervention, and another quarter received intervention without a recorded clinical indication. Both numbers are probably underestimates.

Incidence, risk factors, and consequences of amniotic fluid embolism

BACKGROUND

Amniotic fluid embolism (AFE) is a rare but serious cause of maternal mortality whose aetiology remains obscure. Previous population-based studies have reported associations with labour induction and caesarean delivery.

METHODS

We updated a previous analysis based on the US Nationwide Inpatient Sample from 1999 to 2008. We adapted a diagnostic validation algorithm to minimise false-positive diagnoses, along with statistical methods that account for the stratified random sampling design.

RESULTS

Of the 8 571 209 deliveries recorded in the database, 276 met our case definition of AFE, of which 62 (22.9% of the 274 with known vital status) were fatal. Significant associations with AFE were observed for medical induction {adjusted odds ratio [aOR] = 1.7 [95% confidence interval (CI) 1.2, 2.5]}, caesarean delivery [aOR = 15.0; 95% CI 9.4, 23.9], instrumental vaginal delivery [aOR = 6.6; 95% CI 4.0, 11.1], and cervical/uterine trauma [aOR = 7.4; 95% CI 3.6, 14.9]. AFE was associated with increases in risk of stillbirth, hysterectomy, maternal death, and prolonged maternal length of delivery hospital stay.

CONCLUSIONS

AFE remains an extremely serious obstetric complication with high risks of maternal and fetal mortality. The increased risks of AFE associated with labour induction and caesarean delivery have implications for elective use of these interventions.

Chronic pain after caesarean delivery: an Australian cohort

We investigated the incidence of and risk factors for persistent pain after caesarean delivery. Over a 12-month period, women having caesarean delivery were recruited prospectively at an Australian tertiary referral centre. Demographic, anaesthetic and surgical data were collected and at 24 hour follow-up, women were assessed for immediate postoperative pain and preoperative expectations of pain. Long-term telephone follow-up was conducted at two and 12 months postoperatively. Complete data were obtained from 426 of 469 women initially recruited (90.6%). The incidence of persistent pain at the abdominal wound at two months was 14.6% (n=62) but subsequently reduced to 4.2% (n=18) at 12 months. At two months, 33 patients (7.8%) experienced constant or daily pain. At 12 months, five patients (1.1%) continued to have constant or daily pain which was mild. There was no apparent increase in incidence of persistent pain associated with general versus regional anaesthesia (relative risk [RR] 0.89, 95% confidence interval [CI] 0.49 to 1.6); emergency vs elective procedure (RR 0.65, 95% CI 0.39 to 1.07); higher acute pain scores (RR 1.1, 95% CI 0.69 to 1.75); or history of previous caesarean delivery (RR 0.81, 95% CI 0.50 to 1.33). Persistent pain, usually of a mild nature, is reported by some women two months after their caesarean delivery, but by 12 months less than 1% of women had pain requiring analgesia or affecting mood or sleep. All declined a pain clinic review. Clinicians and patients can be reassured that caesarean delivery is unlikely to lead to severe persistent pain in the long-term.

The Effect of Low-dose Ketamine on Post-caesarean Delivery Analgesia after Spinal Anesthesia

Background

Ketamine, an N-methyl-D-aspartate receptor antagonist, might play a role in postoperative analgesia, but its effect on postoperative pain after caesarean section varies with study design. We investigated whether the preemptive administration of low-dose intravenous ketamine decreases postoperative opioid requirement and postoperative pain in parturients receiving intravenous fentanyl with patient-controlled analgesia (PCA) following caesarean section.

Methods

Spinal anesthesia was performed in 40 parturients scheduled for elective caesarean section. Patients in the ketamine group received a 0.5 mg/kg ketamine bolus intravenously followed by 0.25 mg/kg/h continuous infusion during the operation. The control group received the same volume of normal saline. Immediately after surgery, the patients were connected to a PCA device set to deliver 25-µg fentanyl as an intravenous bolus with a 15-min lockout interval and no continuous dose. Postoperative pain was assessed using the cumulative dose of fentanyl and visual analog scale (VAS) scores at 2, 6, 24, and 48 h postoperatively.

Results

Significantly less fentanyl was used in the ketamine group 2 h after surgery (P = 0.033), but the difference was not significant at 6, 12, and 24 h postoperatively. No significant differences were observed between the VAS scores of the two groups at 2, 6, 12, and 24 h postoperatively.

Conclusions

Intraoperative low-dose ketamine did not have a preemptive analgesic effect and was not effective as an adjuvant to decrease opioid requirement or postoperative pain score in parturients receiving intravenous PCA with fentanyl after caesarean section.

Association of caesarean delivery with child adiposity from age 6 weeks to 15 years

OBJECTIVES

o assess associations of caesarean section with body mass from birth through adolescence.

DESIGN

ongitudinal birth cohort study, following subjects up to 15 years of age.

SETTING AND PARTICIPANTS

Children born in 1991-1992 in Avon, UK who participated in the Avon Longitudinal Study of Parents and Children (ALSPAC) (n=10 219).

OUTCOME MEASURES

PRIMARY OUTCOME

standardized measures of body mass (weight-for length z-scores at 6 weeks, 10 and 20 months; and body mass index (BMI) z-scores at 38 months, 7, 9, 11 and 15 years). Secondary outcome: categorical overweight or obese (BMI: 85th percentile) for age and gender, at 38 months, 7, 9, 11 and 15 years.

RESULTS

Of the 10 219 children, 926 (9.06%) were delivered by caesarean section. Those born by caesarean had lower-birth weights than those born vaginally (-46.1 g, 95% confidence interval(CI): 14.6-77.6 g; P=0.004). In mixed multivariable models adjusting for birth weight, gender, parental body mass, family sociodemographics, gestational factors and infant feeding patterns, caesarean delivery was consistently associated with increased adiposity, starting at 6 weeks (+0.11 s.d. units, 95% CI: 0.03-0.18; P=0.005), through age 15 (BMI z-score increment+0.10 s.d. units, 95% CI: 0.001-0.198; P=0.042). By age 11 caesarean-delivered children had 1.83 times the odds of overweight or obesity (95% CI: 1.24-2.70; P=0.002). When the sample was stratified by maternal pre-pregnancy weight, the association among children born of overweight/obese mothers was strong and long-lasting. In contrast, evidence of an association among children born of normal-weight mothers was weak.

CONCLUSION

Cesarean delivery is associated with increased body mass in childhood and adolescence. Research is needed to further characterize the association in children of normal weight women. Additional work is also needed to understand the mechanism underlying the association, which may involve relatively enduring changes in the intestinal microbiome.

Caesarean delivery in south-western Iran: trends and determinants in a community-based survey

OBJECTIVE

To assess trends in caesarean delivery and its associated factors in south-western Iran.

SUBJECTS AND METHODS

This cross-sectional study was conducted from January 2007 to January 2010 in Fars province, Iran. All deliveries recorded in public and private hospitals were included. The Mann-Whitney U test, χ2 test and multivariate logistic regression models were used for analysis of data. A p value less than 0.05 was considered significant.

RESULTS

The rate of caesarean section for the whole sample of 139,159 increased from 51.6% in 2007 to 53.3% in 2009, which was statistically and clinically significant. The rate of caesarean delivery was significantly higher in primiparous compared to multiparous mothers. The rate increased steadily with the mother's age. The most prevalent recorded reason for caesarean delivery was maternal request. Logistic regression analysis showed that maternal age, previous abortions, underlying maternal disease, gestational age and number of living children were key contributing factors to the choice of mode of delivery.

CONCLUSION

This study showed an increasing rate of caesarean delivery which should draw the attention of policymakers to factors associated with this mode of delivery.

Mode of first delivery and women's intentions for subsequent childbearing: findings from the First Baby Study

BACKGROUND

More than a dozen studies have reported a reduced rate of childbearing after caesarean delivery (CD). It has been hypothesised that this is because women who deliver by CD are less likely to intend to have subsequent children than women who deliver vaginally - either before childbirth or as a consequence of CD. Little research has addressed either of these hypotheses.

METHODS

As part of an ongoing prospective study, we interviewed 3006 women in their third trimester and 1 month after first childbirth to assess subsequent childbearing intentions.

RESULTS

Women who delivered by CD were similar to those who delivered vaginally in intent to have at least one additional child, both before childbirth (90.1% vaginal, 89.9% CD; P = 0.97) and after (87.8% vaginal, 87.1% CD; P = 0.87); however, women who had CD were less likely to intend two or more additional children, both before childbirth (34.7% vaginal, 29.2% CD; P = 0.03) and after (32.2% vaginal, 26.1% CD; P = 0.01). Among women who intended to have at least one additional child before childbirth, 5.0% reported intending to have no additional children 1 month after delivery (5.1% vaginal, 4.6% CD; P = 0.52).

CONCLUSIONS

Women whose first delivery is by CD are less likely to intend a relatively large family of three or more children than those who deliver vaginally, but delivery by CD does not decrease women's intentions to have at least one more child any more than does vaginal delivery, at least in the short term.

Impact of alternative reimbursement strategies in the new cooperative medical scheme on caesarean delivery rates: a mixed-method study in rural China

BACKGROUND

The rate of caesarean delivery (CD) in rural China has been rapidly increasing in recent decades. Due to the exorbitant costs associated with CD, paying for this expensive procedure is often a great challenge for the majority of rural families. Since 2003, the Chinese government has re-established the New Cooperative Medical Scheme (NCMS), aimed to improve the access of essential healthcare to rural residents and reduce financial burden owing to high out of pocket payments. This paper seeks to test the hypothesis that NCMS may provide service users and providers with financial incentives to select CD. It also assesses the effect of different health insurance reimbursement strategies of NCMS on CD rates in rural China.

METHODS

Mixed quantitative and qualitative methods were adopted for data collection. Two cross-sectional household surveys were conducted with women having babies delivered in 2006 and 2009; 2326 and 1515 women, respectively, from the study sites were interviewed using structured questionnaires, to collect demographic and socio-economic data, maternal and child care characteristics and health-related expenditures. Focus group discussions (FGDs) and in-depth key informant interviews (KIIs) were undertaken with policy makers, health managers, providers and mothers to understand their perceptions of the influence of NCMS on the choices of delivery mode.

RESULTS

The CD rates in the two study counties were 46.0 percent and 64.7 percent in 2006, increasing to 63.6 percent and 82.1 percent, respectively, in 2009. The study found that decisions on the selection of CD largely came from the pregnant women. Logistic regression analysis, after adjusting for socio-economic, maternal and fetal characteristics, did not indicate a significant effect of either proportional reimbursement or fixed amount reimbursement on the choice of CD for both study years. Interviews with stakeholders reflected that different reimbursable rates for CD and vaginal deliveries did not have a significant effect on controlling the rising CD rate in the study countries.

CONCLUSION

NCMS reimbursement strategies adopted in the study counties of China did not have a significant effect on the selection of CD for baby deliveries. The rapid rise of the CD rates of rural China has remained a serious issue. Other effective measures, such as health education to increase awareness of mothers' knowledge, and improving training of health staff in evidence-based delivery care, maybe could do more to promote rational baby delivery in rural China.

Preference of ghanaian women for vaginal or caesarean delivery postpartum

OBJECTIVE

To determine Ghanaian women's preferred mode of delivery and opinion of caesarean section after caesarean delivery.

DESIGN

A cross sectional study of women who recently delivered by caesarean section prior to hospital discharge.

SETTING

Two teaching hospitals in Ghana: Komfo Anokye Teaching Hospital, Kumasi, and Korle-Bu Teaching Hospital, Accra.

RESPONDENTS

154 patients who delivered by caesarean section between the 1(st) and 31(st) August, 2003 were interviewed. Of the 154 initiating the interview, 151 completed, and 145 had complete data.

MAIN OUTCOME MEASURES

Delivery preference and general opinion of caesarean delivery.

RESULTS

The majority of women interviewed indicated that they preferred vaginal delivery (55%). Despite preference for vaginal delivery among these women who had delivered by caesarean section, the majority had a generally positive opinion of caesarean section (53%).

CONCLUSION

Ghanaian women with experience of caesarean delivery prefer vaginal delivery.