Maternal age and primary cesarean section rates: a multivariate analysis

Assessing the Factors Affecting Cesarean Section Selection in Iranian Women Using Multilevel Count Models with Excess Zeros

Background

Iran has ranked second in the frequency of cesarean delivery (CD) and this rate in 2014 has increased by 56 percent. The CD has multiple complications for the woman and newborn, and due to the women's readmission after surgery impose additional costs to the countries. Although CD has many complications and is not recommended by obstetrician and midwives; some factors affect the choice of this method of delivery.

Methods

We used data from the Iranian Institute for Health Sciences Research (IIHSR) in 2015. We studied the effects of factors such as socioeconomic and demographic factors and supplemental insurance status in the choice of CD. We used multilevel Zero-Inflated models for the modeling of data.

Results

The employed women resident in urban areas with the high-income and age greater than 34-yr old and supplemental insurance more likely chose CD. On the other hand, women with high education level, women who use at least one media (e.g. Radio, television, etc.) and women that use contraceptive methods have chosen the less CD.

Conclusion

Our findings highlighted the importance of supplemental insurance and socio-economic status in choosing a CD by women. However, in some cases especially in the rich class of society, the high cost of this type of delivery does not affect the choice decrease of it, and governments should adopt rigorous policies in using this method.

Utility of first trimester obstetric ultrasonography before 13 weeks of gestation: a retrospective study

INTRODUCTION

First trimester pregnancy is defined as twelve weeks after the last menstrual period. Ultrasonography has revolutionized validation and management of first trimester pregnancies. The aim was to analyze ultrasonographic findings of first trimester pregnancies in University of Uyo teaching hospital (UUTH), Uyo, Nigeria.

METHODS

The departmental ultrasonographic records of pregnant women who were referred to Radiology department of UUTH, Uyo, Nigeria. For ultrasound scans were retrospectively reviewed. The period under consideration was from 8th January 2013 to 8th February, 2016. Demographic data and ultrasonographic parameters of first trimester pregnancies like gestational sacs were recorded. Data were statistically analyzed using SPSS Chicago 13. Exclusion criterion included incomplete data and acyesis despite positive βhCG test.

RESULTS

26.4% (n-645) of the 2438 pregnant women who underwent obstetric ultrasonography had first trimester ultrasonography during the studied period. The peak frequency was seen in the 20-29 age range with 52.2% (n-337) and followed by 30-39 age range with 41.7% (n-269). The commonest first trimester ultrasound findings was viable pregnancy with 42.5% (n-274), followed by incomplete miscarriage with 34.3% (n-221). The least finding was trophoblastic pregnancies 0.3% (n-2). The earliest age at which normal viable pregnancy was diagnosed in this study was 5weeks 5days from the last menstrual period. Only 2.19% (n-6) of the normal viable pregnancies were multiple pregnancies and they were all twins. The highest number of referrals to Radiology Department for first trimester ultrasonography was from accident and emergency unit with 34.42% (n-222) while antenatal clinic referral was only 16.12% (n-104).

CONCLUSION

The commonest first trimester's obstetric ultrasonographic findings in Uyo, Nigeria are viable pregnancies and are predominantly single gestation. The earliest age of ultasonographic pregnancy detection in Uyo is 5week 5days and peak maternal age is second and third decades.

Midlife Childbearing: Strategies for Informed Decisionmaking

More and more women in the United States are choosing to delay motherhood until their 30s or even 40s. Yet traditional medical advice warns against midlife pregnancy, predicting a variety of adverse reproductive outcomes associated with “advanced maternal age.” Assignment to a high-risk category may result in heightened feelings of concern about pregnancy complications among midlife mothers. Because it is possible that increased emotionality during pregnancy may itself give rise to various childbearing complications, some middle-aged women may become victims of iatrogenic stress during pregnancy. This article first examines critically the medical literature describing the relationship between maternal age and pregnancy outcomes and finds little support for the medical pessimism. Next, the article describes the literature that explores the links between heightened emotionality during pregnancy and various negative outcomes and suggests that, despite serious methodological flaws, there is some evidence that fear-induced stress during pregnancy may place certain middle-aged women at higher risk for complications. Finally, strategies for improved decisionmaking and for enhancing the pregnancy experience of midlife women are proposed.

Impact of maternal age on delivery outcomes following spontaneous labour at term

AIM

Pregnancy in women of advancing maternal age is linked to incrementally worsening perinatal outcome. The aim of this study is to assess the impact of maternal age on delivery outcome in women that spontaneously labour at term.

METHODS

This was a retrospective study of women that spontaneously labour at term. Women with singletons in spontaneous onset labour beyond 37 weeks of gestation were divided into five maternal age groups: <19 years, 20-24 years, 25-29 years, 30-34 years and >35 years by their age at delivery. The main outcome variables are augmentation of labour, caesarean section, assisted vaginal delivery, and perineal trauma, while admission of the newborn into the neonatal unit within 24 h following delivery was the secondary outcome measure.

RESULTS

A total of 30,022 met the inclusion criteria with primiparae and multiparae accounting for 46 and 54%, respectively. Increasing age in primiparae was associated with; augmentation of labour OR 2.05 (95% CI 1.73-2.43), second degree perineal tear 1.35 (1.12-1.61), assisted vaginal delivery 1.92 (1.53-2.41) and caesarean section 4.23 (3.19-5.12). While that for multiparae; augmentation of labour OR 1.93 (1.05-3.52), perineal trauma 2.50 (1.85-3.34), assisted vaginal delivery 4.95 (91.82-13.35) and caesarean section 1.64 (1.13-2.38). The secondary outcome measure did not reach statistical significance.

CONCLUSION

Increasing maternal age is an independent risk factor for operative delivery, and perineal trauma. However, maternal age has no significant effect on admission of infants into the NICU during the first 24 h following delivery.

Pregnancy after the age of 40

Many regard childbearing as the most life-changing and perhaps the most desirable aspect of a women's life. Correspondingly, reduced fertility has a significant negative impact on a woman and her family. To this end, gynecologists work to preserve and restore fertility. Recently, however, in developed countries, more women are becoming pregnant later in life, whether by choice or circumstance. This could be a direct result of the increasing availability of both effective contraception and infertility treatment, but perhaps more pertinently the changing lifestyles and career choices that modern women make. This article offers a perspective on pregnancy after the age of 40, the impact on maternal and fetal outcomes, the social implications and the importance of prenatal counseling.

Impact of maternal age on obstetric outcome

OBJECTIVE

To estimate the effect of maternal age on obstetric outcomes.

METHODS

A prospective database from a multicenter investigation of singletons, the FASTER trial, was studied. Subjects were divided into 3 age groups: 1) less than 35 years, 2) 35-39 years, and 3) 40 years and older. Multivariable logistic regression analysis was used to assess the effect of age on outcomes after adjusting for race, parity, body mass index, education, marital status, smoking, medical history, use of assisted conception, and patient's study site.

RESULTS

A total of 36,056 women with complete data were available: 28,398 (79%) less than 35 years of age; 6,294 (17%) 35-39 years; and 1,364 (4%) 40 years and older. Increasing age was significantly associated with miscarriage (adjusted odds ratio [adjOR]2.0 and 2.4 for ages 35-39 years and age 40 years and older, respectively), chromosomal abnormalities (adjOR 4.0 and 9.9), congenital anomalies (adjOR 1.4 and 1.7), gestational diabetes (adjOR 1.8 and 2.4), placenta previa (adjOR 1.8 and 2.8), and cesarean delivery (adjOR 1.6 and 2.0). Patients aged 35-39 years were at increased risk for macrosomia (adjOR 1.4). Increased risk for abruption (adjOR 2.3), preterm delivery (adjOR 1.4), low birth weight (adjOR 1.6), and perinatal mortality (adjOR 2.2) was noted in women aged 40 years and older.

CONCLUSION

Increasing maternal age is independently associated with specific adverse pregnancy outcomes. Increasing age is a continuum rather than a threshold effect.

[Pregnancy beyond age 40 in 382 women: a retrospective study in Reunion Island]

OBJECTIVE

To examine obstetrical and neonatal outcomes among women age 40 years and older.

MATERIAL AND METHODS

There was a retrospective study including 382 pregnant women at least 40 years of age and 7786 controls aged 20-34, stratified according to parity. Associations between maternal age and pregnancy outcomes were assessed using Pearson's chi(2) test, Fischer exact test, Student test or Mann and Whitney test, as appropriate.

RESULTS

Maternal age 40 and over was associated with an increased risk for gestational diabetes (multiparas: OR 3.2, 95%CI 2.2-4.8; grandmultiparas: 2.8, 1.6-5.0), chronic diabetes (multiparas: 3.5, 1.04-10.6), chronic hypertension (multiparas: 3.1, 1.5-6.1; grandmultiparas: 12.1, 3.3-53.2), pregnancy-induced hypertension (nulliparas: 4.6, 1.01-17.3; multiparas: 2.6, 1.3-5.4) and preclampsia (multiparas: 2.9, 1.1-7.2). The risk for cesarean section was 2-fold higher in older multiparas and grandmultiparas. The same was true for the rate of operative vaginal delivery. The rate of fetal chromosomal abnormalities was 7-fold higher in older gravidas. Rates of fetal death were significantly increased in the cohort of older pregnant women (nulliparas: 11.2, 2.9-44.0; multiparas: 3.9, 1.4-10.9).

CONCLUSION

Pregnancy at age 40 and over is associated with high rates of obstetrical complications, cesarean sections and operative vaginal deliveries, emphasizing the importance of rigorous antenatal care.

Primary and repeat caesarean sections: comparison of indications

In this retrospective study, we describe and compare the clinical indications of primary and repeat caesarean sections. We review caesarean deliveries at the Princess Badeea Teaching Hospital in North Jordan performed between 1 January and 26 November 1995 (n=740). The indication for the procedure was extracted based on the surgeon's operative reports. The hospital caesarean rate during the study period was 8.8%; 22.7% of these were repeat procedures (n=168). Elective caesarean delivery was the leading cause of repeat sections, followed by dystocia, others, breech and fetal distress. In contrast, breech presentation, dystocia and fetal distress were the leading indications for primary caesarean section. Ninetynine patients (59%) undergoing repeat caesarean had absolute or relative contraindication to trial of labour. The majority of primary caesarean are clinically indicated. Caesarean section rates can be lowered if we address the repeat elective procedures.

A predictive model for cesarean section in low risk pregnancies

OBJECTIVE

A small number of women with low risk pregnancies undergo cesarean section. A model that can predict this risk and therefore identify these women will be of help in several hospitals where personnel and resources are limited.

METHODS

The study consisted of 2 parts. All charts of women with low risk singleton pregnancies admitted to labor room over a 5-month period were analyzed. Adjusted odds ratios were calculated to find out relative importance of each risk factor and likelihood ratios were obtained. These were prospectively applied to 1010 consecutive low risk women and the post test probability calculated. Finally the actual incidence of cesarean section was compared with posttest probability derived from predictors.

RESULTS

A combination of maternal age >24 years, primiparity and height <150 cm or a combination of any 2 of the 3 variables is significantly associated with increased cesarean section rate. Individually, primiparity, height <150 cm or age >24 years also significantly increased the chances of cesarean section.

CONCLUSIONS

A predictive model consisting of maternal age, parity and height can be used to identify low risk pregnant women who are likely to require cesarean section.

Association between maternal age and the likelihood of a cesarean section: a population-based multivariate logistic regression analysis

BACKGROUND

A majority of studies examining the relationship between advancing maternal age and the likelihood of cesarean section (CS) use data from regional samples or from a limited number of medical institutions. This study uses population-based data from Taiwan to explore the relationship between maternal age and the likelihood of a CS.

METHODS

The National Health Insurance Research Database (NHIRD) on registries of medical facilities and board-certified physicians and monthly claim summaries for inpatients were used. In total, 502 524 singleton deliveries were included in the study. Multivariate logistic regressions were performed with the presence of CS as the dependent variable and maternal age (<20, 20-29, 30-34 and >34 years) as the independent variable. The study controlled for maternal indications, institution characteristics, maternal requests and attending physician characteristics.

RESULTS

CS rates for the age groups <20, 20-29, 30-34 and >34 years were 17.7, 27.4, 37.4 and 47.5%, respectively. The regression analyses consistently showed that the likelihood of a CS significantly increased with advancing maternal age within each category of complication after adjusting for medical institution characteristics and characteristics of the attending physician.

CONCLUSIONS

This study found that, after adjusting for maternal indications, and healthcare institution and physician characteristics, there was a significant relationship between advancing maternal age and an increased likelihood of a CS. This finding, together with the high CS rate of 32.1% in Taiwan, one of the highest reported in the world today, highlights an imperative need to devise interventions to reduce the frequency of CSs.

Recent Trends in Caesarean Delivery Rates and Indications for Caesarean Delivery in Canada

OBJECTIVE

To examine recent trends in Caesarean delivery rates as well as the indications for Caesarean delivery in Canada, excluding the provinces of Manitoba and Quebec.

METHODS

All deliveries (N = 1 807 388) recorded in the Canadian Institute for Health Information's Discharge Abstract Database for the years 1994/95 to 2000/01 were included in the study (all hospital deliveries in Canada except for those occurring in Manitoba and Quebec). Temporal trends and inter-provincial/territorial variations in Caesarean delivery rates were quantified, and the primary indications for Caesarean delivery during the study period were compared.

RESULTS

The overall Caesarean delivery rate increased from 18.0% in 1994/95 to 22.1% in 2000/01. The primary Caesarean delivery rate increased from 12.7% to 16.3%, while the rate of vaginal birth after Caesarean decreased from 33.3% to 28.5% over the same period. Most of the increase in primary Caesarean deliveries was due to increases in Caesarean deliveries for dystocia, which increased from 6.9% in 1994/95 to 9.2% in 2000/01. The largest increase in repeat Caesarean deliveries was due to elective repeat Caesarean sections, which increased from 37.7% to 40.3%. Approximately 15% of the increase in overall Caesarean delivery rates was explained by increases in maternal age. The rate of vaginal deliveries following forceps rotation declined from 1.9% in 1994/95 to 1.3% in 2000/01.

CONCLUSION

Most of the recent increase in Caesarean delivery rates in Canada was attributed to increases in primary Caesarean delivery for dystocia and elective repeat Caesarean deliveries.

Explaining the association of maternal age with Cesarean delivery for nulliparous and parous women

METHOD

We used data on 6,805 live births from the National Maternal and Infant Health Survey to examine the positive association between maternal age and Cesarean delivery.

RESULTS

For parous women, the unadjusted risk ratio [RR] for Cesarean, comparing 35 year olds with 20 year olds, was estimated to be 1.40 [95% confidence limits (CL)=1.18, 1.65]; this association disappeared upon adjustment for obstetrical predictors and other factors (adjusted RR=1.04; 95% CL=0.80, 1.35). In contrast, for nulliparous women, the unadjusted risk ratio was 2.16 (95% CL=1.78, 2.63) and remained substantial upon adjustment (RR=1.74; 95% CL=1.25, 2.43).

CONCLUSION

These results, along with baseline risk information, suggest that older nulliparous women and their obstetricians should be the target of future efforts to control Cesarean rates.

Can obstetric complications explain the high levels of obstetric interventions and maternity service use among older women? A retrospective analysis of routinely collected data

OBJECTIVE

To determine whether the higher levels of obstetric intervention and maternity service use among older women can be explained by obstetric complications.

DESIGN

A retrospective analysis of routinely collected data from the Aberdeen Maternity and Neonatal Databank.

PARTICIPANTS

All residents of Aberdeen city district delivering singleton infants at the Maternity Hospital 1988-1997 (28,484 deliveries).

MAIN OUTCOME MEASURES

Odds ratios for each intervention in older maternal age groups compared with women aged 20-29. Interventions considered include obstetric interventions (induction of labour, augmentation, epidural use, assisted delivery, caesarean section) and raised maternity service use (more than two prenatal scans, amniocentesis, antenatal admission to hospital, admission at delivery of more than five days, infant resuscitation, and admission to the neonatal unit).

METHODS

Logistic regression was used to investigate the association between maternal age and the incidence of interventions. The odds ratios for each intervention were then adjusted for relevant obstetric complications and maternal socio-demographic characteristics.

RESULTS

Levels of amniocentesis, caesarean section, assisted delivery, induction, and augmentation (in primiparae) are all higher among older women. Maternity service use also increases significantly with age: older women are more likely to have an antenatal admission, more than two scans, a hospital stay at delivery of more than five days, and have their baby admitted to a neonatal unit. Controlling for relevant obstetric complications reveals several examples of effect modification, but does not eliminate the age effect for most interventions in most groups of women.

CONCLUSIONS

Higher levels of intervention among older women are not explained by the obstetric complications we considered.

Predicting cesarean delivery with decision tree models

OBJECTIVE

The purpose of this study was to determine whether decision tree-based methods can be used to predict cesarean delivery.

STUDY DESIGN

This was a historical cohort study of women delivered of live-born singleton neonates in 1995 through 1997 (22,157). The frequency of cesarean delivery was 17%; 78 variables were used for analysis. Decision tree rule-based methods and logistic regression models were each applied to the same 50% of the sample to develop the predictive training models and these models were tested on the remaining 50%.

RESULTS

Decision tree receiver operating characteristic curve areas were as follows: nulliparous, 0.82; parous, 0.93. Logistic receiver operating characteristic curve areas were as follows: nulliparous, 0.86; parous, 0.93. Decision tree methods and logistic regression methods used similar predictive variables; however, logistic methods required more variables and yielded less intelligible models. Among the 6 decision tree building methods tested, the strict minimum message length criterion yielded decision trees that were small yet accurate. Risk factor variables were identified in 676 nulliparous cesarean deliveries (69%) and 419 parous cesarean deliveries (47.6%).

CONCLUSION

Decision tree models can be used to predict cesarean delivery. Models built with strict minimum message length decision trees have the following attributes: Their performance is comparable to that of logistic regression; they are small enough to be intelligible to physicians; they reveal causal dependencies among variables not detected by logistic regression; they can handle missing values more easily than can logistic methods; they predict cesarean deliveries that lack a categorized risk factor variable.

Breastfeeding duration among low income women

Breastfeeding has been identified as a possible deterrent to the development of osteoporosis and breast cancer in women. In addition, infants who are breastfed exclusively for at least 4 months reportedly have fewer incidence of SIDS, ear infection, diarrhea, and allergies. Further, low income women who breastfeed may be empowered by the experience. Increasing the frequency and duration of breastfeeding is recognized as a national priority, particularly for low income, minority women. Yet, recent national data indicate that in 1997, only 16.5% of low income mothers breastfed for at least 6 months. Short breastfeeding duration in low income women may be due to problems unique to them; thus, consistent and comprehensive breastfeeding support should be provided by midwives, nurses, lactation consultants, and peer counselors who are skilled in culturally sensitive management of lactation within the context of limited financial and social resources. This article focuses on the benefits of breastfeeding, and factors that may influence its duration. It also explores culturally relevant strategies as well as suggested interventions to increase breastfeeding duration among low-income women.

[Factors associated to the trial of labor in primipara women with one previous cesarean section]

OBJECTIVE

The purpose of this study was to identify medical and non-medical factors associated to the performance of a trial of labor during the second delivery of women with one previous cesarean section.

METHODS

This was a nested case control study, with a secondary data analysis from a retrospective population based cohort study. It was primarily performed on a population of women who had had their first children in Campinas, SP, Brazil, during 1985. The study population was constituted of the 1,352 women of the cohort study who had had their first deliveries by cesarean section and also had their second deliveries no matter when. The group of cases (333 women, almost 25%) was constituted of those women who had a trial of labor during their second deliveries and the control group (1,019 women) of those who had not had it. For each possible associated factor evaluated, the Odds Ratio and its respective 95% Confidence Interval were calculated. For the ordered categorical variables, the chi2 for trend was also calculated. Finally, a non conditional multivariate regression analysis was performed, identifying the significant factors and then estimating their adjusted Odds Ratio.

RESULTS

The main factors associated with the trial of labor in this situation were a low monthly family income, having public medical insurance by the national health system, a low maternal age, the occurrence of rupture of membranes during the second delivery, and having been in childbirth during the first delivery.

CONCLUSION

It is concluded that the main determinants for a trial of labor among primipara women with one previous cesarean section were basically social and economic factors, rather than medical ones.

Are women requiring unplanned intrapartum epidural analgesia different in a low-risk population?

We studied 645 full-term low-risk women in early labour in 6 units to evaluate the effects of maternal characteristics and obstetric management in early labour on the use of epidural analgesia, and to analyse the relationship between epidural analgesia, progress of labour and mode of delivery using multiple logistic regression. Among variables present in early labour, nulliparity, ethnicity and obstetric unit were the strongest predictors of epidural analgesia requirement. In nulliparous women, obstetric unit affected use of epidural analgesia (P<0.05) and induction of labour was associated with increased use of epidural analgesia (odds ratio 3.45, 95% CI: 1.45-7.90). In multiparous women, only ethnicity was statistically significant (P<0.05). Epidural analgesia was associated with longer labours and more instrumental deliveries (odds ratio 2.93, 95%CI: 1.48-5.83). In the epidural group, however, we found a positive correlation between first stage duration and elapsed time before epidural analgesia. Furthermore, rate of cervical dilation was similar in the non epidural group throughout the first stage (mean 3.41 cm/h, 95%CI: 3.19-3.63) and in the epidural group after epidural analgesia decision (mean 3.99, 95% CI: 2.96-5.02), while the mean cervical dilatation rate before epidural analgesia was 0.88 cm/h (95% CI: 0.72-1.04). The need for epidural analgesia is, therefore, multifactorial and difficult to predict. Whereas nulliparity increases epidural analgesia requirement, data on the progress of labour before pain relief suggest that epidural analgesia is a marker of pain severity and/or labour failure rather than the cause of delayed progress in low-risk pregnancies.

Labour outcome of low-risk multiparas of 40 years and older. A case-control study

Between January 1, 1994 and December 31, 1997 a total of 76 low-risk multiparas of 40 years and older with spontaneous onset of labour were delivered and were compared with 152 younger (25-30 years-old) low-risk multiparas of similar parity in a case-control study. The labour and perinatal outcomes of the 2 groups were compared. The duration of the first stage of labour was longer (233 minutes versus 149 minutes, p<0.0005) in the older women. Significantly more labours of older multiparas were complicated by intrapartum fetal distress (6.6% versus 1.3%, p<0.05); received intramuscular analgesia (11.8% versus 2.6%, p<0.01); and had operative deliveries (17.1% versus 4.6%, p<0.01). The incidence of instrumental delivery (11.8% versus 3.9%, p<0.05) and Caesarean section (5.3% versus 0.7%, p<0.05) were higher among older multiparas. The incidences of Syntocinon augmentation of labour, prolonged second stage, episiotomy and third stage complications such as perineal tear, primary postpartum haemorrhage, and retained placenta were similar in both groups. Both groups had similar perinatal outcomes. These women should be treated as others with high-risk pregnancies with appropriate careful attention during labour such as continuous fetal heart rate monitoring. They should be counselled to be made aware of the increased risks during labour.

Does advanced maternal age affect pregnancy outcome in women with mild hypertension remote from term?

OBJECTIVES

Our purpose was to compare maternal and perinatal outcomes of mature women with those in younger women with pregnancies complicated by mild hypertension remote from term.

STUDY DESIGN

A matched cohort design was used. A total of 379 mature pregnant women (> or = 35 years old) with mild hypertension remote from term were matched for race, gestational age, and proteinuria status at enrollment with 379 adult controls aged 20 to 30 years also with mild hypertension remote from term. All were enrolled in an outpatient management program that included automated blood pressure measurements and daily assessment of weight, proteinuria, and fetal movement.

RESULTS

The mean gestational age at enrollment was 32.7 +/- 3.0 weeks for both groups (range 24 to 36 weeks). By matching 20.6% of patients in each group had > or = 1+ proteinuria on urinary dipstick at enrollment, and 77.3% of patients in each group were white. Chronic hypertension was more common in the mature group (22.4% vs 14.5%, p = 0.007). The mean gestational age at delivery (37.2 +/- 2.3 vs 37.2 +/- 2.2 weeks), the mean pregnancy prolongation (28.1 +/- 21.0 vs 28.4 +/- 22.0 days), and the mean birth weights (2864 +/- 770 vs 2906 +/- 788 gm) were similar between the mature and younger groups (all p > 0.05). There were no differences regarding abruptio placentae (2 vs 3 cases) or thrombocytopenia or HELLP (hemolysis, elevated liver enzymes, low platelets) syndrome (7 vs 9 cases), and there were no cases of eclampsia. There were five stillbirths in the mature group and none in the younger group (p = 0.063).

CONCLUSION

Outpatient management of mild hypertension remote from term in the mature pregnant women was associated with similar maternal outcomes but with a nonstatistically higher stillbirth rate compared with the younger pregnant woman.

Multivariate analysis of risk factors for operative delivery in nulliparous women. Canadian Early Amniotomy Study Group

OBJECTIVE

Our purpose was to develop predictive models of operative delivery in nulliparous women on the basis of sociodemographic, anthropometric, and obstetric risk factors.

STUDY DESIGN

Data were obtained prospectively on 925 nulliparous women in spontaneous term labor with a single fetus in cephalic presentation. Operative delivery was defined as either a midforceps or a cesarean delivery. Variables were grouped into two categories: those that could be assessed at admission and those appearing during labor. Multiple logistic regression was used to identify variables predictive of operative delivery.

RESULTS

Among variables that can be documented at admission, independent predictors of operative delivery were maternal age and height, pregnancy weight gain, smoking status, gestational age, and admission cervical dilatation. Of these, maternal age > or = 35 years was the most strongly related to operative delivery. When variables documented later during labor were added to this first model, variables retained in the second model were age and height, smoking status, presence of dystocia, epidural analgesia, and fetal heart rate tracing abnormalities. The adjusted odds ratio of operative delivery in the presence of epidural anesthesia was 3.4 (95% confidence interval 2.0 to 5.8). This association was similar in the presence or absence of dystocia. When the specificity was in the range of 85%, the first and second models have sensitivities of 34% and 48%, respectively, and positive predictive values of 39% and 46%, respectively, which is higher than the a priori risk of operative delivery in the study population (21%).

CONCLUSIONS

The models, based on data easily available, may help to predict the need for midforceps or cesarean section in low-risk nulliparous women. Before application in a clinical setting, these statistical models require validation in a separate cohort. The observed association between epidural anesthesia and operative delivery deserves interest but clinical trials are required to determine whether this relation is causal.

Very advanced maternal age: pregnancy after age 45

OBJECTIVE

Our purpose was to describe the maternal and fetal outcomes of pregnancies in women > or = 45 years old at delivery.

STUDY DESIGN

A retrospective review of in-hospital deliveries after 20 weeks of gestation was performed in four Utah tertiary care hospitals for the 10-year period between 1985 and 1994.

RESULTS

Seventy-nine cases were identified among 126,500 births, with an incidence of 0.63 per 1000 births. Maternal ages were 45 (n = 44), 46 (n = 21), and > or = 47 (n = 14) years. Three of the conceptions were assisted, including both twin gestations. Thirty-seven (46.8%) had obstetric complications during pregnancy; the most frequent complications were gestational diabetes (12.7%) and preeclampsia (10.1%). Median (range) gestational age at delivery was 39 (22.9 to 41.7) weeks; 12 (15.2%) deliveries occurred before 37 weeks. Eight (9.9%) karyotype abnormalities were diagnosed. The cesarean section rate was 31.7%; the most frequent indications were abnormal lie (n = 9), fetal distress (n = 5), and previous cesarean delivery (n = 5). There were no maternal deaths. Median (range) birth weight was 3466 (397 to 5085) gm; 14 (17.3%) were < 2500 gm and 16 (19.8%) were > 4000 gm. Twelve (14.8%) infants were admitted to the neonatal intensive care unit. The corrected perinatal mortality rate was 1.3% (1/78).

CONCLUSIONS

In women > 45 years old at delivery maternal and fetal outcomes were generally good, but there was a high incidence of pregestational (chronic hypertension, hypothyroidism) and gestational (karyotype abnormalities, gestational diabetes, cesarean section, macrosomia) complications. This information may be helpful for counseling women between 45 and 50 years old who are considering pregnancy.

Sequelae of repeat cesarean sections

OBJECTIVES

To study and analyze the factors related to repeat cesarean section and to highlight the problems that may be associated with it.

METHODS

The study was carried out in the Department of Obstetrics and Gynaecology, King Khalid University Hospital, Riyadh, Saudi Arabia, and involved 395 patients who had had two or more previous cesarean sections prior to the current pregnancy. Various factors which may be associated with repeat cesarean sections, as well as the outcome of the operations, were assessed and analyzed. The chi2-test and other analyses were used to examine the association between the number of cesarean sections and the various variables.

RESULTS

Four or more previous cesarean sections was significantly associated with dense adhesions. On the other hand, height, parity, antenatal clinic attendance, postoperative complications, fetal weight and fetal outcome had no significant effect on, nor influenced, the multiplicity of cesarean sections.

CONCLUSION

No specific risk is associated with repeat cesarean sections that is not normally associated with single cesarean sections.

High delivery intervention rates in nulliparous women over age 35

OBJECTIVE

To assess the effect of maternal age and parity on obstetric interventions and pregnancy outcome.

STUDY DESIGN

A retrospective review of 35,140 deliveries including 4268 parturients aged 35 years or more (1985-1992). Obstetrical interventions and outcome were analyzed in relation to age and parity.

RESULTS

Nulliparous women aged 35 years or more had a 2-fold increase in cesarean delivery rate over younger nulliparae, and 50% more cesarean deliveries than the multiparae aged 35 years or more. Similar trends were observed in preterm labor, labor induction, breech presentation, and instrumental delivery. Higher risk was encountered in neonatal 1 min Apgar scores < 3, and in admissions to the neonatal intensive care unit. There were no differences in all parameters between women over age 40 and women aged 35-40 years. The perinatal mortality was not increased and was similar in all groups.

CONCLUSIONS

Nulliparae aged more than 35 years are at increased risk for interventions and cesarean sections. However, women aged 35-40 have a similar risk as women aged over 40 years.

Underappreciated risks of the elderly multipara

OBJECTIVE

Our purpose was to identify the age-related increased risks of the elderly gravida by clarifying the effects of age and parity, their combination, and their interaction.

STUDY DESIGN

We studied 9556 singleton pregnancies in women aged 20 to 29 years or > or = 35 years delivered over an 8-year period. Data were analyzed by stepwise multiway contingency table analysis, with p < 0.002 considered significant.

RESULTS

Many of the previously reported risks of the elderly gravida are expected on the basis of age and parity. Significant associations (primarily related to advanced age) included higher frequencies of obesity, chronic hypertension, gestational diabetes, and large-for-gestational-age and macrosomic infants. These elderly gravidas, on the other hand, had fewer postdates pregnancies. Although often overlooked, the greatest age-related increases in risk for induction (1.8 times), preeclampsia (2.7 times), gestational diabetes (4.5 times), clinical diabetes (3.2 times), oxytocin use (1.7 times), and macrosomia (1.6 times) occur in multiparas, not nulliparas. The risk for preeclampsia in the elderly multipara is significantly higher than expected on the basis of age and parity.

CONCLUSION

The increased risks of the elderly multipara may have been overshadowed by the previous focus on the elderly nullipara. It is important to recognize the increases in age-related risks of the elderly multipara to appropriately counsel and manage this group of patients.

Prenatal predictors of cesarean section due to labor arrest

Cesarean section due to labor arrest occurs because the fetus is too large for the maternal outlet tract. If these women could be identified prior to labor, patient management could be optimized for both the clinician and the woman. A case-control study was designed to identify predictors of Cesarean section due to labor arrest. A five year retrospective review identified 32 cases and 329 controls with complete data for the prenatal maternal variables. Both cases and controls were considered for the stepwise logistic regression model. The prenatal variables predicting Cesarean section due to labor arrest are parity, history of past macrosomia, maternal age, term fundal height and maternal height. This model can be considered a pilot model that can be tested in a large international/inter-ethnic population.

Epidemiologic predictors of cesarean section in nulliparous patients at low risk. RADIUS Study Group. Routine Antenatal Diagnostic Imaging with Ultrasound Study

OBJECTIVES

We sought to determine whether certain maternal and fetal characteristics influenced the risk of maternal- and fetal-indicated cesarean sections in pregnant women at low risk for adverse perinatal outcomes.

STUDY DESIGN

From a cohort of 6393 low-risk nulliparous patients maternal and fetal indicated cesarean section rates with 95% confidence intervals were calculated and stratified by demographic, anthropometric, and clinical tests and measurements. The strongest risk factors were modeled by means of multiple logistic regression.

RESULTS

Few risk factors distinguished maternal from fetal characteristics preceding cesarean delivery. Maternal age was associated with increased cesarean section risk in the tallest group of women only, and cesarean section rates decreased with increasing height, increased with higher prepregnancy weights, and was highest in women carrying male fetuses. Higher first prenatal visit diastolic blood pressure, increasing numbers of nonstress tests, > or = 2+ prenatal urine protein, late sonograms, geographic region, and practice type were statistically significant risk factors as well. Interestingly, results of prenatal visit tests and measurements contributed less to the prevalence of cesarean section than did age, fetal sex, and anthropometric parameters. However, the generalizability of these results is limited to low-risk (predominantly white) populations.

CONCLUSIONS

Of the risk factors we were able to assess, a large proportion of the incidence of cesarean section in this population of nulliparous patients at low risk was attributable to age, sex of fetus, and anthropometric patient profiles.

Cesarean section: medical benefits and costs

Cesarean section rates have risen dramatically in the U.S. over the past 20 years. Although infant mortality has declined during the same period, there is little evidence that more frequent cesarean surgery is the cause. Cesareans save lives or benefit health in certain circumstances, but the incidence of those indications has not increased. Cesarean section also has risks, the most significant for the infant being iatrogenic prematurity or respiratory disease. Maternal mortality is 2-4 times higher and morbidity is 5-10 times higher after a cesarean compared to vaginal birth. The four indications responsible for most of the rise in cesarean rates--previous cesarean, dystocia, breech presentation, and fetal distress--are those conferring the least clear-cut benefit. Demographically, women who are most likely to experience pregnancy complications, low birth weight births, or infant mortality are least likely to have a cesarean. Social, economic, and other factors seem to have a greater influence on the decision to perform a cesarean than does expected medical benefit. The development of neonatal intensive care, expanded access to prenatal care, and greater availability of abortion and family planning have contributed more to falling infant mortality. It has been estimated that approximately half the cesareans currently performed in the U.S. are medically unnecessary, resulting in considerable avoidable maternal mortality and morbidity, and a cost of over $1 billion each year.

Midwifery care and out-of-hospital birth settings: how do they reduce unnecessary cesarean section births?

In studies using matched or adjusted cohorts, U.S. women beginning labor with midwives and/or in out-of-hospital settings have attained cesarean section rates that are considerably lower than similar women using prevailing forms of care--physicians in hospitals. This cesarean reduction involved no compromise in mortality and morbidity outcome measures. Moreover, groups of women at elevated risk for adverse perinatal outcomes have attained excellent outcomes and cesarean rates well below the general population rate with these care arrangements. How do midwives and out-of-hospital birth settings so effectively help women to avoid unnecessary cesareans? This paper explores this question by presenting data from interviews with midwives who work in home settings. The midwives' understanding of and approaches to major medical indications for cesarean birth contrast strikingly with prevailing medical knowledge and practice. From the midwives' perspective, many women receive cesareans due to pseudo-problems, to problems that might easily be prevented, or to problems that might be addressed through less drastic measures. Policy reports addressing the problem of unnecessary cesarean births in the U.S. have failed to highlight the substantial reduction in such births that may be expected to accompany greatly expanded use of midwives and out-of-hospital birth settings. The present study--together with cohort studies documenting such a reduction, studies showing other benefits of such forms of care, and the increasing reluctance of physicians to provide obstetrical services--suggests that childbearing families would realize many benefits from greatly expanded use of midwives and out-of-hospital birth settings.

Medically unnecessary cesarean section births: introduction to a symposium

Between 1965 and 1986, the United States cesarean section rate increased from 4.5 to 24.1%. Increasingly, childbearing women and their advocates, along with many others, have recognized that a large proportion of cesareans confers a broad array of risks without providing any medical benefit. A growing literature examines the diverse causes of medically unnecessary cesareans and the diverse effects of surgical birth on women, infants, and families. Various programs and policies have been proposed or implemented to reduce cesarean rates. In recent decades, many other nations have also experienced a sharply escalating cesarean section rate. It is reasonable to conclude that a largely uncontrolled international pandemic of medically unnecessary cesarean births is occurring. The level of political, analytic, and programmatic activity that has occurred in the U.S. regarding medically unnecessary surgical births does not seem to be paralleled in other nations with sharply escalating rates. This symposium was organized with the objective of presenting the U.S. experience with various dimensions of the problem of medically unnecessary cesareans to an international audience. Although preliminary and inadequate, it is hoped that this experience will encourage policy leaders and investigators throughout the world to recognize and address the problem of run-away cesarean section births. The first section of this introduction summarizes the U.S. experience with medically unnecessary cesareans from the perspective of trends, causes, consequences, and solutions. The second section covers the same topics, presenting selected material from various other nations throughout the world. In the course of these overviews, I introduce the symposium's seven contributions, most of which focus on circumstances in the U.S.

Factors that influence route of delivery--active versus traditional labor management

OBJECTIVE

Our purpose was to compare maternal and fetal factors that influence the route of delivery with active management of labor and a traditional labor management protocol.

STUDY DESIGN

Data were collected prospectively on 346 consecutive patients receiving active management of labor and 354 patients who were managed traditionally. Within each group demographic and labor characteristics of patients undergoing cesarean section were compared with those of patients having vaginal deliveries by means of the Student t test, chi 2 analysis, and stepwise logistic regression.

RESULTS

With both active management of labor and traditional labor management success in achieving vaginal delivery was related to the station of the fetal vertex at admission, the need for oxytocin augmentation of labor, the uterine response to oxytocin, the use of epidural anesthesia, and the development of chorioamnionitis. By means of multiple logistic regression analysis maternal age, height, payor status, and birth weight were also identified as risk factors for cesarean section with traditional labor management but not with active management of labor.

CONCLUSIONS

Differences were identified in risk factors for cesarean section between active management and traditional labor management. Active management of labor may diminish or eliminate some patient characteristics as risk factors for cesarean birth.

Supportive nurse-midwife care is associated with a reduced incidence of cesarean section

OBJECTIVE

Our purpose was to examine whether care by a certified nurse-midwife, including personal labor support, was associated with a reduced risk of cesarean delivery.

STUDY DESIGN

A retrospective cohort study comparing 3551 physician-managed patients with 1056 certified nurse-midwife-managed patients in a university hospital with a mixed socioeconomic and ethnic population was performed. Regression analysis was used to estimate the risk of labor abnormalities, diagnosis of fetal distress, and cesarean delivery in patients delivered by a certified nurse-midwife vs a physician and to control for maternal age, race, parity, fetal size, and delivery year. Subjects included were women having at least five prenatal visits who were delivered of term, singleton, liveborn infants without congenital anomalies with occiput presentation.

RESULTS

Odds ratio for cesarean section for women delivered by certified nurse-midwives versus those delivered by physicians was 0.71 (95% confidence interval 0.55, 0.91). Midwifery care was associated with a lower risk of abnormal labor (adjusted odds ratio 0.70, 95% confidence interval 0.60, 0.83) and diagnosis of fetal distress (adjusted odds ratio 0.50, 95% confidence interval 0.32, 0.77).

CONCLUSION

This work demonstrates that labor abnormalities and diagnosis of fetal distress are less frequent in patients cared for by nurse-midwives, and there is an association with a lower incidence of cesarean section.

Cesarean section and maternal age in low-risk nulliparas

The relationship between maternal age and cesarean section in low-risk nulliparas was analysed in 7454 perinatal clinical records selected from eleven databases of Latin American institutions obtained with a comprehensive perinatal information system. The risk of cesarean section in nulliparas between 29 and 49 years of age was found to be three times higher than that corresponding to pregnant women of lesser age. This clearly more aggressive obstetrical conduct could not be explained by the main indications for cesarean section.

Pregnancy outcome in medically complicated and uncomplicated patients aged 40 years or older

Patients (183) who were delivered at age greater than or equal to 40 years were studied to ascertain the nature and frequency of maternal and fetal complications at a single institution in a recent time period. These patients were further grouped into those of low parity, those who began pregnancy without underlying disease, and those who began pregnancy with underlying medical disorders. For the entire group preeclampsia, premature labor, precipitate labor, and malpresentation were significantly more common. The rate of vaginal delivery was substantially decreased, and serious postpartum morbidity was relatively common. The incidence of stillbirth, perinatal mortality, and abnormal birth weight was significantly increased. There were some differences in the nature and frequency of complications encountered among the subgroups, but no subgroup had a complication rate comparable to our general obstetric population.