Prepartum and intrapartum caesarean section rates at Mater Mothers’ Hospital Brisbane 1997-2005

A comparative study on third trimester fetal biometric parameters with maternal age

Background

Advanced maternal age is an important parameter associated with increased risk of feto-maternal complications and it is an evolving trend in society for women planning for pregnancy in late ages. However there are no studies done whether advanced maternal age has its effects on expression of growth pattern in the fetus. So this study was done to compare the maternal age with the third trimester fetal biometric parameters.

Methods

This study was done in 100 antenatal women and divided into two groups: Group 1: optimal maternal age group between 21-29 years of age and Group 2: advanced maternal age 30 and above. The pre-pregnant maternal weight, gestational age and third trimester fetal biometrics using ultrasound are noted and compared between the groups.

Results

The maternal weight gain between the groups was optimal but the third trimester fetal parameters were significantly less in advanced maternal age. The abdominal circumference in optimal age group and head circumference in advanced maternal age group was closer to calculated estimated date of delivery (EDD) and would be specific in calculating the gestational age.

Conclusions

Though there is no significant difference in maternal weight gain, there are fetal growth restrictions in advanced maternal age group due to which the third trimester fetal parameters are lesser than the optimal age group. Head circumference would be specific in calculating the estimated date of delivery in advanced maternal age group.

The Maternal Age Cut-Off for an Increase in Composite Adverse Outcomes

OBJECTIVE

To investigate whether there is a specific maternal age cut-off at which there is an increase in maternal and neonatal adverse outcomes.

METHODS

A retrospective study comparing maternal and neonatal outcomes between nulliparous women of different ages. The receiver operating characteristic model with the Youden index was used to find the best age cut-off using cesarean delivery (CD) and composite adverse outcomes. A multivariable logistic regression analysis was calculated after adjusting for smoking, induction of labour, epidural use, hypertensive disorders, gestational diabetes, and birth weight.

RESULTS

The study included 11 343 nulliparous women. Age 28 years was found to be the cut-off age at which we found a significant increase in adverse outcomes. Women older than age 28 years had a higher risk of CD than women younger than 28 years (35.7% vs. 21.3%, P < 0.0001). They were also more likely to deliver prematurely (11.9% vs. 7.9%, P < 0.0001) and had higher rates hypertensive disorders (2.3% vs. 1.1%, P < 0.0001) and gestational diabetes mellitus (0.4% vs. 0.1%, P = 0.001). Furthermore, their babies were more likely to be growth restricted (1.1% vs. 0.3%, P < 0.0001). There were no differences in the rates of induction of labour or macrosomia. After adjusting for confounders, we found that women older than 28 years had higher risks of CD and adverse outcomes than younger women (aOR 1.9; 95% CI 1.744-2.1 and aOR 1.6; 95% CI 1.6-1.77, respectively).

CONCLUSION

Increasing maternal age is independently associated with adverse maternal and neonatal outcomes with an age cut-off of 28 years. Women older than age 28 years are at higher risk for composite adverse outcomes than younger women.

Placentas From Women of Advanced Maternal Age

CONTEXT.—

The percentage of pregnant women with advanced maternal age (AMA) has increased during the past several decades due to various socioeconomic factors and advances in assisted reproduction. These pregnancies are associated with adverse maternal and fetal outcomes. However, the underlying placental pathology has not been well described.

OBJECTIVE.—

To investigate the placental histopathology associated with AMA pregnancies.

DESIGN.—

Placental pathology from 168 AMA women 35 years or older at delivery was reviewed. The cases were subdivided into 2 age subgroups, ages 35 to 39 and 40 or older, as well as a "pure AMA" subgroup where the only indication for placental examination was AMA. A group of 60 consecutive non-AMA placentas was also identified and used as comparison. The spectrum of histologic features in each case was catalogued.

RESULTS.—

Of the overall AMA cases, meconium deposition was seen in 55% (93 of 168), chorangiosis in 40% (68 of 168), and acute chorioamnionitis in 36% (60 of 168). Fetal vascular malperfusion was also seen with high frequency (30%; 50 of 168). Two histologic alterations found to be significantly different between the 35 to 39 and greater than 40 age subgroups were fetal vascular malperfusion (11% [7 of 65] versus 42% [43 of 103]; P = .001) and delayed villous maturation (1.5% [1 of 65] versus 13% [13 of 103]; P = .02). The pure AMA subgroup showed no statistically significant differences compared with the overall AMA group. Chronic deciduitis was the only statistically significant difference between the overall AMA group and the non-AMA comparison group (14% [23 of 168] versus 30% [18 of 60]; P = .02).

CONCLUSIONS.—

Our findings, particularly the high frequency of fetal vascular malperfusion, suggest that AMA should be an independent indication for placental pathologic examination.

Correlates of C-section in Punjab: a disaggregated analysis at the level of rural-urban residential status and place of delivery

The World Health Organization-recommended rate of delivery by Caesarean section (C-Section) is 10-15% of all live births, but in Punjab, the largest province of Pakistan, this rate was 23% in 2014. The perception is that an inadequate public health sector forces women toward the private sector where C-Section is routinely conducted without valid medical reasons, posing risks to women's health and incurring catastrophic out-of-pocket expenditures. This study identified the correlates of C-section delivery and whether they differed by the urban/rural residence of women and place of delivery (public vs. private). Using multivariate logistic regression analyses of data from the Multiple Indicators Cluster Survey (MICS) collected from June-October, 2014 for all women who gave birth in the prior two years (N = 10,558), we found that rich women were statistically no different from poor women in their odds of delivery by C-section in the generally more expensive private health facilities (adjusted odds ratio [aOR] 1.23; 95% confidence interval [CI] 0.88-1.71); rich women were more likely to deliver by C-section in the less expensive public health facilities (aOR 2.03; 95% CI 1.13-3.63). This paradox may reflect the inefficiency of the health system and suggests limited affordable alternatives for poor women in the public sector.

The impact of maternal age on foetal growth patterns and newborn size

The association patterns between maternal age and foetal growth parameters as well as newborn size were analysed using a dataset of 4737 singleton term births taking place at the Viennese Danube hospital. Foetal growth patterns were reconstructed by the results of three ultrasound examinations carried out at the 11th/12th, 20th/21th and 32th/33thweek of gestation. In detail, crown-rump length, biparietal diameter, fronto-occipital diameter, head circumference, abdominal transverse diameter, abdominal anterior-posterior diameter, abdominal circumference, and femur length were determined. Birth weight, birth length and head circumference were measured immediately after birth. Young teenage mothers (≤15 years), older adolescent mothers (16-19 years), mothers of optimal age range (20-35 years) and mothers of advanced age (>35 years) differed significantly in body height, pre-pregnancy weight status and gestational weight gain. Surprisingly, the foetuses of young adolescent mothers were the largest ones during first trimester. During the second and third trimester however, the foetuses of mothers of optimal age range (20-35 years) and mothers older than 35 years showed larger biometric dimensions than adolescent mothers. According to multiple regression analyses, maternal age was significantly related to Foetal head size (ß =-0.04; 95% CI = -0,08 – 0.01; p=0.034) and abdominal dimensions (ß= 0.03; 95% CI = 0.01-0.05; p=0,011) during the second trimester and to birthweight (ß= -0.03; 95% CI= -4.40 – 0.04; p=0.050). The associations however, are quite weak and the statistical significance is maybe due to the large sample size. At the time of birth, offspring of mothers of optimal age range (20 to 35 years) is significantly larger than that of adolescent mothers and mothers of advanced age. Mothers of advanced age showed the significantly highest (p=<0.0001) prevalence (5.6%) of SGA newborns (<2500g). The small size of newborn among young adolescent mothers may be due to a competition over nutrients between the still growing mothers and the foetuses during the third trimester, while placental ageing may be responsible for smaller size of offspring among mothers of advanced age.

Factors promoting or inhibiting normal birth

BACKGROUND

In response to rising rates of medical intervention in birth, there has been increased international interest in promoting normal birth (without induction of labour, epidural/spinal/general anaesthesia, episiotomy, forceps/vacuum, or caesarean section). However, there is limited evidence for how best to achieve increased rates of normal birth. In this study we examined the role of modifiable and non-modifiable factors in experiencing a normal birth using retrospective, self-reported data.

METHODS

Women who gave birth over a four-month period in Queensland, Australia, were invited to complete a questionnaire about their preferences for and experiences of pregnancy, labour, birth, and postnatal care. Responses (N = 5840) were analysed using multiple logistic regression models to identify associations with four aspects of normal birth: onset of labour, use of anaesthesia, mode of birth, and use of episiotomy. The probability of normal birth was then estimated by combining these models.

RESULTS

Overall, 28.7% of women experienced a normal birth. Probability of a normal birth was reduced for women who were primiparous, had a history of caesarean, had a multiple pregnancy, were older, had a more advanced gestational age, experienced pregnancy-related health conditions (gestational diabetes, low-lying placenta, high blood pressure), had continuous electronic fetal monitoring during labour, and knew only some of their care providers for labour and birth. Women had a higher probability of normal birth if they lived outside major metropolitan areas, did not receive private obstetric care, had freedom of movement throughout labour, received continuity of care in labour and birth, did not have an augmented labour, or gave birth in a non-supine position.

CONCLUSIONS

Our findings highlight several relevant modifiable factors including mobility, monitoring, and care provision during labour and birth, for increasing normal birth opportunity. An important step forward in promoting normal birth is increasing awareness of such relationships through patient involvement in informed decision-making and implementation of this evidence in care guidelines.

Differences in nulliparous caesarean section rates across models of care: a decomposition analysis

BACKGROUND

To evaluate the extent of the difference in elective (ELCS) and emergency (EMCS) caesarean section (CS) rates between nulliparous women in public maternity hospitals in Ireland by model of care, and to quantify the contribution of maternal, clinical, and hospital characteristics in explaining the difference in the rates.

METHODS

Cross-sectional analysis using a combination of two routinely collected administrative databases was performed. A non-linear extension of the Oaxaca-Blinder method is used to decompose the difference between public and private ELCS and EMCS rates into the proportion explained by the differences in observable maternal, clinical, and hospital characteristics and the proportion that remains unexplained.

RESULTS

Of the 29,870 babies delivered to nulliparous women, 7,792 were delivered via CS (26.1 %), 79.6 % of which were coded as EMCS. Higher prevalence of ELCS was associated with breech presentation, other malpresentation, and the mother being over 40 years old. Higher prevalence of EMCS was associated with placenta praevia or placental abruption, diabetes (pre-existing and gestational), and being over 40 years old. The private model of care is associated with ELCS and EMCS rates 6 percentage points higher compared than the public model of care but this differential is insignificant in the fully adjusted models for EMCS. Just over half (53 %) of the 6 percentage point difference in ELCS rates between the two models of care can be accounted for by maternal, clinical and hospital characteristics. Almost 80 % of the difference for EMCS can be accounted for.

CONCLUSIONS

The majority of the difference in EMCS rates across models of care can be explained by differing characteristics between the two groups of women. The main contributor to the difference was advancing maternal age. The unexplained component of the difference for ELCS is larger; an excess private effect remains after accounting for maternal, clinical, and hospital characteristics. This requires further investigation and may be mitigated in future with the introduction of clinical guidelines related to CS.

Advanced Maternal Age and Risks for Adverse Pregnancy Outcomes: A Population-Based Study in Oman

To test the hypothesis that advanced maternal age (AMA) of 35 years and above is associated with increased risk of adverse pregnancy outcomes, we performed a population-based retrospective study using data from the 2000 National Health Survey in Oman. The last pregnancy outcomes of mothers aged ≥35 years were compared with adult mothers aged 20-34 years using bivariate and multivariate statistical techniques. Significantly increased risks of spontaneous abortion, gestational diabetes, preeclampsia, prolonged labor, and cesarean section delivery have been observed for advanced maternal age. Our findings may contribute to cross-cultural understanding of the risks associated with AMA and will facilitate evidence-based counseling of older expectant mothers.

Would it be too late? A retrospective case-control analysis to evaluate maternal-fetal outcomes in advanced maternal age

PURPOSE

To evaluate maternal-fetal outcomes in women of advanced maternal age (AMA; >35 years old) and women of physiological maternal age as controls (C; <35 years old).

METHODS

Single-center, retrospective case-control analysis, from January 1 to December 31, 2013. For each group, we evaluated obstetric history, number of twin pregnancies, delivery mode, incidence of obstetric diseases and neonatal outcomes (5-min Apgar score, neonatal weight, meconium stained fluid rate, admission to the neonatal intensive care unit rate, and incidence of congenital malformations). Data are presented as n (%) and analyzed with χ (2) test and Fisher exact test (when required). A p value < 0.05 was considered statistically significant. Moreover, we calculated the odds ratio (OR), with confidence interval (CI) at 95 %.

RESULTS

We enrolled 1,347 pregnant women, 210 (15.6 %) in AMA and 1,137 (84.4 %) C. AMA patients showed a higher rate of previous (anamnestic) spontaneous abortion (SA; p = 0.001; OR = 2.10) and previous (anamnestic) voluntary pregnancy termination (p = 0.022; OR = 1.59), iterative cesarean section (p = 0.026; OR = 2.33), SA (p = 0.001; OR = 12.82), preterm delivery (p = 0.001; OR = 69.84), congenital malformations (p = 0.036; OR = 3.94). In C there was a greater number of nulliparous (p = 0.009; OR = 0.52) and vaginal deliveries (p = 0.025; OR = 0.41). There were not any statistically significant differences between the two groups for twin pregnancies (p = 0.862; OR = 0.97), first cesarean section (p = 0.145; OR = 0.95), other obstetric diseases and neonatal outcomes.

CONCLUSION

AMA could be considered an important risk factor only for SA and PTD and does not influence neonatal outcomes except for congenital malformations.

Why 'down under' is a cut above: a comparison of rates of and reasons for caesarean section in England and Australia

BACKGROUND

Most studies examining determinants of rising rates of caesarean section have examined patterns in documented reasons for caesarean over time in a single location. Further insights could be gleaned from cross-cultural research that examines practice patterns in locations with disparate rates of caesarean section at a single time point.

METHODS

We compared both rates of and main reason for pre-labour and intrapartum caesarean between England and Queensland, Australia, using data from retrospective cross-sectional surveys of women who had recently given birth in England (n = 5,250) and Queensland (n = 3,467).

RESULTS

Women in Queensland were more likely to have had a caesarean birth (36.2%) than women in England (25.1% of births; OR = 1.44, 95% CI = 1.28-1.61), after adjustment for obstetric characteristics. Between-country differences were found for rates of pre-labour caesarean (21.2% vs. 12.2%) but not for intrapartum caesarean or assisted vaginal birth. Compared to women in England, women in Queensland with a history of caesarean were more likely to have had a pre-labour caesarean and more likely to have had an intrapartum caesarean, due only to a previous caesarean. Among women with no previous caesarean, Queensland women were more likely than women in England to have had a caesarean due to suspected disproportion and failure to progress in labour.

CONCLUSIONS

The higher rates of caesarean birth in Queensland are largely attributable to higher rates of caesarean for women with a previous caesarean, and for the main reason of having had a previous caesarean. Variation between countries may be accounted for by the absence of a single, comprehensive clinical guideline for caesarean section in Queensland.

Advanced maternal age and adverse pregnancy outcome: evidence from a large contemporary cohort

BACKGROUND

Recent decades have witnessed an increase in mean maternal age at childbirth in most high-resourced countries. Advanced maternal age has been associated with several adverse maternal and perinatal outcomes. Although there are many studies on this topic, data from large contemporary population-based cohorts that controls for demographic variables known to influence perinatal outcomes is limited.

METHODS

We performed a population-based cohort study using data on all singleton births in 2004-2008 from the North Western Perinatal Survey based at The University of Manchester, UK. We compared pregnancy outcomes in women aged 30-34, 35-39 and ≥40 years with women aged 20-29 years using log-linear binomial regression. Models were adjusted for parity, ethnicity, social deprivation score and body mass index.

RESULTS

The final study cohort consisted of 215,344 births; 122,307 mothers (54.19%) were aged 20-29 years, 62,371(27.63%) were aged 30-34 years, 33,966(15.05%) were aged 35-39 years and 7,066(3.13%) were aged ≥40 years. Women aged 40+ at delivery were at increased risk of stillbirth (RR = 1.83, [95% CI 1.37-2.43]), pre-term (RR = 1.25, [95% CI: 1.14-1.36]) and very pre-term birth (RR = 1.29, [95% CI:1.08-1.55]), Macrosomia (RR = 1.31, [95% CI: 1.12-1.54]), extremely large for gestational age (RR = 1.40, [95% CI: 1.25-1.58]) and Caesarean delivery (RR = 1.83, [95% CI: 1.77-1.90]).

CONCLUSIONS

Advanced maternal age is associated with a range of adverse pregnancy outcomes. These risks are independent of parity and remain after adjusting for the ameliorating effects of higher socioeconomic status. The data from this large contemporary cohort will be of interest to healthcare providers and women and will facilitate evidence based counselling of older expectant mothers.

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.

Impact of health policy based on the self-management program on Cesarean section rate at a tertiary hospital in Taiwan

BACKGROUND/PURPOSE

In 2005, a self-management program, based on the global budget system that met the criteria for reducing Cesarean delivery rates, was introduced to obstetric practices in Taiwan. The purpose of this study was to examine the impact of different national health policies on the Cesarean delivery rate at a tertiary hospital.

METHODS

We constructed a Poisson regression model and conducted an interrupted time series analysis to detect the effects of the implementation of each health policy on Cesarean deliveries. We used data collected at two points before the implementation of the global budget system (GBS) policy (in 2001 and 2002), and at two points after the implementation of the hospital-based self-management (HBSM) policy (in 2005 and 2010). All monthly data were collected at these time points.

RESULTS

Between June 2001 and August 2010, the rate of improvement of vaginal birth after Cesarean section (VBAC) during Period 1 revealed that VBAC may have long-term effects (p < 0.001). While there may have been a remarkable immediate improvement in the VBAC rate (p = 0.0276) in Period 3, the long-term effect of VBAC seemed to have decreased during the same period (p = 0.0003). Following the synergistic impacts of health policy implementation during Period 3, the immediate improved total Cesarean section (C/S) rate seemed to be maintained at an average value (p = 0.0183).

CONCLUSION

Over the long term, the C/S rate seemed to reach a plateau; the immediate effect on the VBAC rate was a significant increase consistent with that of the initial health policy implementation.

Breastfeeding after cesarean delivery: a systematic review and meta-analysis of world literature

BACKGROUND

The rate of exclusive breastfeeding remains low in many countries. Furthermore, cesarean delivery (CD) is increasing and may affect breastfeeding success.

OBJECTIVE

The objective was to conduct a systematic review and meta-analysis of observational studies to determine whether CD (prelabor or in-labor) is associated with a lower rate of breastfeeding compared with vaginal delivery (VD).

DESIGN

Studies published before January 2011 that reported breastfeeding up to 6 mo postpartum and compared outcomes after CD or VD, including foreign language publications, were identified through PubMed and bibliographic review. Prespecified data were extracted independently by multiple observers. The types of CD [prelabor (elective/scheduled) or in-labor (emergency)] were compared by subgroup analyses. Potential sources of study-level bias were analyzed by using meta-regression and sensitivity analyses.

RESULTS

The systematic review included 53 studies (554,568 subjects, 33 countries); 25 authors contributed additional data (245,455 subjects), and 48 studies (553,306 subjects, 31 countries) were included in the meta-analysis. Rates of early breastfeeding (any initiation or at hospital discharge) were lower after CD compared with after VD (pooled OR: 0.57; 95% CI: 0.50, 0.64; P < 0.00001) and lower after prelabor but not after in-labor CD (prelabor OR: 0.83; 95% CI: 0.80, 0.86; P < 0.00001; in-labor OR: 1.00; 95% CI: 0.97, 1.04; P = 0.86). In mothers who initiated breastfeeding, CD had no significant effect on any breastfeeding at 6 mo (OR: 0.95; 95% CI: 0.89, 1.01; P = 0.08).

CONCLUSIONS

There was a negative association between prelabor CD and early breastfeeding. If breastfeeding is initiated, mode of delivery has no apparent effect on the number of mothers still breastfeeding at 6 mo. Women and health care workers should be aware of the negative associations between CD and early breastfeeding and consequent implications for infants' well-being.

The health implications of birth by Caesarean section

Since the first mention of fetal programming of adult health and disease, a plethora of programming events in early life has been suggested. These have included intrauterine and postnatal events, but limited attention has been given to the potential contribution of the birth process to normal physiology and long-term health. Over the last 30 years a growing number of studies have demonstrated that babies born at term by vaginal delivery (VD) have significantly different physiology at birth to those born by Caesarean section (CS), particularly when there has been no exposure to labour, i.e. pre-labour CS (PLCS). This literature is reviewed here and the processes involved in VD that might programme post-natal development are discussed. Some of the effects of CS are short term, but longer term problems are also apparent. We suggest that VD initiates important physiological trajectories and the absence of this stimulus in CS has implications for adult health. There are a number of factors that might plausibly contribute to this programming, one of which is the hormonal surge or "stress response" of VD. Given the increasing incidence of elective PLCS, an understanding of the effects of VD on normal development is crucial.

Hidden costs associated with the universal application of risk management in maternity care

This paper presents a critical analysis of risk management in maternity care and the hidden costs associated with the practice in healthy women. Issues of quality and safety are driving an increased emphasis by health services on risk management in maternity care. Medical risk in pregnancy is known to benefit 15% or less of all pregnancies. Risk management applied to the remaining 85% of healthy women results in the management of risk in the absence of risk. The health cost to mothers and babies and the economic burden on the overall health system of serious morbidity has been omitted from calculations comparing costs of uncomplicated caesarean birth and uncomplicated vaginal birth. The understanding that elective caesarean birth is cost-neutral when compared to a normal vaginal birth has misled practitioners and contributed to over use of the practice. For the purpose of informing the direction of maternity service policy it is necessary to expose the effect the overuse of medical intervention has on the overall capacity of the healthcare system to absorb the increasing demand for operating theatre resources in the absence of clinical need.

Older maternal age and intervention in labor: a population-based study comparing older and younger first-time mothers in Victoria, Australia

BACKGROUND

In Australia, birth rates for women aged 35 years or more are significant and increasing and a considerable percentage are first births. This study investigated the effect of maternal age on interventions in labor and birth for primiparous women aged 35 to 44 years compared with primiparous women aged 25 to 29 years.

METHODS

All primiparous women who gave birth in Victoria, Australia, in 2005 and 2006 (n = 57,426) were included in this population-based cross-sectional study. Women were stratified by admission status (private/public). Main outcome measures were induction of labor, augmentation of labor, use of epidural analgesia, and method of birth. Multivariate logistic regression was used to explore the relationship between maternal age and cesarean adjusted for confounders.

RESULTS

Older women were more likely to give birth by cesarean section whether admitted as public or private patients. For private patients, total cesarean rates were 31.8 percent (25-29 yr), 46.0 percent (35-39 yr), and 60.0 percent (40-44 yr; p < 0.001) compared with 27.5, 41.6, and 53.4 percent for public patients (p < 0.001). Older women who experienced labor were more likely to have an instrumental vaginal birth or an emergency cesarean section than younger women. Both were more common in women admitted as private patients. Age-related trends were also seen for induction of labor and use of epidural analgesia. Rates were higher for private patients. Rates of induction were (37.8, 40.2, and 42.5%) for private patients compared with (32.1, 36.7, and 40.1%) for public patients and rates for epidural were (45.3, 49.9, and 48.1%) among private patients compared with (33.3, 38.8, and 39.3%) among public patients.

CONCLUSIONS

Interventions in labor and birth increased with maternal age, and this effect was seen particularly for cesarean section among women admitted privately. These findings were not fully explained by the complications we considered.

Contribution of select maternal groups to temporal trends in rates of caesarean section

OBJECTIVE

To estimate the contribution of select maternal groups to temporal trends in Caesarean section (CS) rates.

METHODS

Using the Nova Scotia Atlee Perinatal Database, all deliveries by CS during the 24-year period from 1984 to 2007, at the Women's Hospital, IWK Health Centre were identified. Deliveries by CS were classified into groups using parity (nullipara/multipara), plurality (singleton/multiple), presentation (cephalic/breech/transverse), gestational age (term/preterm), history of previous CS (previous CS/no previous CS), and labour (spontaneous/induced/no labour). CS rates in each group and the contribution of each group to the overall CS rate was determined for three eight-year epochs. The risk of CS in each group over time, accounting for identified maternal, fetal, and obstetric practice factors, was evaluated using logistic regression.

RESULTS

Of 113,016 deliveries, 23,232 (20.6%) were identified as deliveries by CS meeting the inclusion and exclusion criteria. The CS rate rose from 16.8% in 1984 to 1991 to 26.8% in 2000 to 2007 (P < 0.001). The biggest contributors to the overall CS rate in the last study epoch (2000-2007) were nulliparous women with singleton, cephalic, term pregnancies with spontaneous or induced labour; women with singleton, cephalic, term pregnancies with previous CS; and women with breech presentation. Adjusted analyses explained some increases in the rate of CS and demonstrated reduced risks in others.

CONCLUSION

Only some temporally increased CS rates in select maternal groups remain increased after adjusting for confounding variables. The identification of potentially modifiable maternal risk factors, re-evaluation of the indications and techniques for induction of labour in nulliparous women, provision of clinical services for vaginal birth after Caesarean section, and external cephalic version for selected breech presentation are important clinical management areas to consider for safely lowering the Caesarean section rate.