The Effect of Work Activity in Pregnancy on the Risk of Severe Preeclampsia

Summary: The aim of this study was to evaluate the impact of type of employment and level of physical activity at work on the risk of severe preeclampsia. For this purpose, we carried out a case control study of 160 nulliparous pregnant women with severe preeclampsia and 320 normotensive nulliparous controls who received prenatal care from members of one medical staff. The type of employment and the level of physical activity sustained at work were ascertained at birth through an interview based on a standard questionnaire. The degree of physical activity at work was assessed by a 4-level activity score based on type of work, physical intensity, posture at work, and weekly working hours. In logistic regression analysis, after adjustment for potential confounders (maternal age, time of stopping work, prepregnancy body mass index, social status of the partner, history of previous abortion, and prepregnancy smoking status), clerical workers had a significantly lower risk of severe preeclampsia than women who were unemployed at the beginning of pregnancy (OR 0.53, 95% CI 0.30, 0.96). In multivariate analysis, there was a significant linear trend relating the degree of physical activity at work, to the risk of preeclampsia (likelihood chi-square = 9.38, 3 df, p = 0.002). We then restricted the analysis to women who had ever worked in pregnancy (n = 339) also adjusting for confounders, and found that clerical workers were still at significantly lower risk of severe preeclampsia dian women not formally employed (OR 0.2,95% CI 0.08,0.49). In addition, moderate/high physical activity at work was associated with a 2-fold increase in the risk of severe preeclampsia compared to mild activity (OR 2.08, 95% CI 1.11,3.88). We conclude that moderate to high physical activity at work seems to increase the risk of severe preeclampsia.     

History of abortion,preterm, term birth,and risk of preeclampsia: a population-based study

OBJECTIVE: The objective of this study was to examine the effect of previous abortion and preterm and term birth on the incidence of preeclampsia in subsequent pregnancies. STUDY DESIGN: A population-based retrospective cohort study was conducted that was based on 140,773 pregnancies that had delivered between 1993 and 1999 in 49 hospitals in Northern and Central Alberta, Canada. Multivariate logistic regression was applied to estimate odds ratios, with 95% confidence intervals, and to control for confounding variables. RESULTS: No significant difference was found in the incidence of preeclampsia in nulliparous women with previous abortion (2.6%) as compared to nulliparous women without previous abortion (2.9%; adjusted odds ratio, 0.89; 95% confidence interval, 0.78-1.01; P >.05). A single previous abortion was associated with a slightly decreased risk of preeclampsia (adjusted odds ratio, 0.84; 95% confidence interval, 0.72-0.97; P <.05). However, 2 and > or =3 abortions were not associated with a decreased risk of preeclampsia. In women with no history of previous abortion and term pregnancy, there was no significant difference in incidence of preeclampsia between women who had previous preterm birth (2.7%) and primigravid women (2.8%; adjusted odds ratio, 0.71; 95% confidence ratio, 0.48-1.03; P >.05). However, > or =2 previous preterm births were associated with a decreased risk of preeclampsia (adjusted odds ratio, 0.28; 95% confidence interval, 0.09-0.84; P <.01). The incidence of preeclampsia was markedly lower in multiparous women who previously delivered at term (0.9%) as compared to the incidence in primigravida women (2.9%; adjusted odds ratio, 0.29; 95% confidence interval, 0.26-0.33; P <.001). The adjusted odds ratios of preeclampsia for women with 1, 2, 3, and > or =4 previous term pregnancies were 0.32 (95% confidence interval, 0.28-0.36), 0.27 (95% confidence interval, 0.22-0.34), 0.22 (95% confidence interval, 0.15-0.33), and 0.21 (95% confidence interval, 0.12-0.35), respectively. CONCLUSION: A history of term pregnancy (> or =37 weeks) conveys a substantial "protection" against preeclampsia in the subsequent pregnancy.     

Emergency cesarean delivery in induction of labor: an evaluation of risk factors

BACKGROUND: Induction of labor has been associated with an increased risk of emergency cesarean delivery. Knowledge of factors that influence the risk of cesarean delivery in women with induced labor is limited. METHODS: We performed a case-control study, nested within a population-based cohort of women with induced labor at term during 1991-1996 in Uppsala County, Sweden. Cases were women delivered with emergency cesarean delivery, and controls were women vaginally delivered (n = 193, respectively). Using logistic regression, analyses were performed. Odds ratio (OR) with 95% confidence intervals (CI) was used as a measure of relative risk. RESULTS: Women with a previous cesarean delivery had high risks of cesarean delivery (adjusted OR = 10.10, 95% CI = 3.30-30.92). The risk of cesarean delivery was also increased among nulliparous (adjusted OR = 4.92, 95% CI = 2.81-8.61), short (adjusted OR = 2.20, 95% CI = 1.06-4.59), and obese women (adjusted OR = 2.03, 95% CI = 1.07-3.84). A cervix dilatation less than 1.5 cm doubled the risk of cesarean delivery (adjusted OR = 2.26, 95% CI = 1.09-4.66). Mother's age, epidural analgesia, oxytocin augmentation, gestational age, and birthweight were not significantly associated with risks of cesarean delivery. CONCLUSIONS: Women with a previous cesarean delivery, nulliparous, short, and obese women with induced labor are at high risk of a cesarean delivery. When there is a need to deliver a woman with a previous cesarean section or a nulliparous woman with other risk factors for cesarean delivery, it may be prudent to consider an elective cesarean section.     

子痫前期高危因素的Logistic回归分析

目的:探讨影响子痫前期发病的主要高危因素及早期预测方法.方法:按照病例对照研究设计,对119例子痫前期病例和236例正常产妇对照组进行相关因素的回顾性调查,采用Logistic回归方法进行单因素和多因素分析,在此基础上建立子痫前期发病的预测模型,并对该模型进行初步评价.结果:孕前BMI≥24kg/m~2(OR=6.142,95%CI 3.361～11.225),高血压、糖尿病、肾炎疾病史(OR=14.092,95%CI 1.669～118.983),自然流产史(OR=3.008,95%CI1.160～7.801),高血压家族史(OR=3.050,95%CI 1.738～5.350)是子痫前期发病的主要危险因素.以Y=0.27作为判断界值,所建模型的后验灵敏度和特异度分别为68.1%和72.5%.结论:应加强对孕前BMI≥24 ks/m~2,有高血压、糖尿病、肾炎疾病史,有自然流产史及高血压家族史的妇女进行孕前及孕期保健,以预防及早期预测子痫前期的发生.     

Family history of hypertension and diabetes in relation to preeclampsia risk in Peruvian women

In a case-control study of 169 preeclamptics and 201 controls, we assessed maternal parental history of chronic hypertension and diabetes in relation to preeclampsia risk among Peruvian women. Participants provided information on parental history of the two conditions and other covariates during postpartum interviews. Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) adjusted for confounding by age, parity and prepregnancy adiposity. In this population, women were more likely to know the diabetes status of their parents than their hypertension status. Compared with women without a parental history of hypertension, women with a parental history of hypertension experienced a 20% increased risk of preeclampsia (OR = 1.2; 95% CI 0.7-2.2) that did not reach statistical significance. Women with a positive parental history for diabetes had a 3.4-fold increased risk of preeclampsia (95% CI 1.4-8.4). Women with a positive parental history of both hypertension and diabetes, as compared with those whose parents had neither condition, experienced a 4.6- fold increased risk of preeclampsia (OR = 4.6; 95% CI 0.9-23.0). Our results are generally consistent with the thesis that parental history of hypertension and diabetes reflects genetic and behavioral factors whereby women may be predisposed to an increased risk of preeclampsia.     

Risk of cesarean delivery with elective induction of labor at term in nulliparous women.

OBJECTIVE: To quantify the risk of cesarean delivery associated with elective induction of labor in nulliparous women at term. METHODS: We performed a cohort study on a major urban obstetric service that serves predominantly private obstetric practices. All term, nulliparous women with vertex, singleton gestations who labored during an 8-month period (n = 1561) were divided into three groups: spontaneous labor, elective induction, and medical induction. The risk of cesarean delivery in the induction groups was determined using stepwise logistic regression to control for potential confounding factors. RESULTS: Women experiencing spontaneous labor had a 7.8% cesarean delivery rate, whereas women undergoing elective labor induction had a 17.5% cesarean delivery rate (adjusted odds ratio [OR] 1.89; 95% confidence interval [CI] 1.12, 3.18) and women undergoing medically indicated labor induction had a 17.7% cesarean delivery rate (OR 1.69; 95% CI 1.13, 2.54). Other variables that remained significant risk factors for cesarean delivery in the model included: epidural placement at less than 4 cm dilatation (OR 4.66; 95% CI 2.25, 9.66), epidural placement after 4 cm dilatation (OR 2.18; 95% CI 1.06, 4.48), chorioamnionitis (OR 4.61; 95% CI 2.89, 7.35), birth weight greater than 4000 g (OR 2.59; 95% CI 1.69, 3.97), maternal body mass index greater than 26 kg/m2 (OR 2.36; 95% CI 1.61, 3.47), Asian race (OR 2.35; 95% CI 1.04, 5.34), and magnesium sulfate use (OR 2.18; 95% CI 1.04, 4.55). CONCLUSION: Elective induction of labor is associated with a significantly increased risk of cesarean delivery in nulliparous women. Avoiding labor induction in settings of unproved benefit may aid efforts to reduce the primary cesarean delivery rate.     

BMI as a modifying factor in the relations between age at menarche, menstrual cycle characteristics, and risk of preeclampsia.

To examine the relations between age at menarche and menstrual cycle characteristics and preeclampsia risk, we analyzed data from a case-control study conducted from 1998 to 2002. Usual menstrual cycle characteristics among 286 preeclampsia cases and 471 normotensive controls were assessed using a structured interview during postpartum hospitalization. We used multivariable logistic regression to estimate odds ratios (OR) and 95% confidence intervals (CI), adjusting for confounders. We also examined the influence of pre-pregnancy body mass index (BMI) on selected hypothesized relations. Among lean women (pre-pregnancy BMI < 25 kg/m(2)), preeclampsia risk was lower in those reporting cycles > or = 36 days in length (adjusted OR 0.78, CI 0.35-1.83) and menarche at > or = 14 years (adjusted OR 0.48, 95% CI 0.28-0.82). In contrast, among overweight or obese women, preeclampsia risk was higher in those with long cycles (OR 3.11, 95% CI 0.62-1.56, p(interaction) = 0.16) and late menarche (OR 1.53, 95% CI 0.59-3.97, p(interaction) = 0.03). These data suggest that adiposity influences the relations between usual menstrual cycle length, age at menarche, and preeclampsia. Overweight women with long cycles are at particularly high preeclampsia risk.     

Primary preeclampsia in the second pregnancy: effects of changes in prepregnancy body mass index between pregnancies

OBJECTIVE: To examine the association between changes in prepregnancy body mass index (BMI) between a woman's first two pregnancies and incidence of preeclampsia in the second pregnancy. METHODS: We performed a population-based retrospective cohort analysis using data on women's first two singleton pregnancies (n=136,884) in Missouri (1989-1997). The study was restricted to women without preeclampsia in the first pregnancy. Prepregnancy BMI (kg/m(2)) was categorized as underweight (less than 18.5), normal (18.5-24.9), overweight (25-29.9), and obese (30 or greater). Analyses were adjusted for confounders through multivariable logistic regression. RESULTS: The incidence rate of preeclampsia in the second pregnancy was 2.0%. In comparison with women who were of normal BMI in both pregnancies, the risk for preeclampsia increased when BMI changed between the first two pregnancies from underweight to obese (odds ratio [OR] 5.6, 95% confidence interval [CI] 1.7-18.2), normal to overweight (OR 2.0, 95% CI 1.7-2.3), normal to obese (OR 3.2, 95% CI 2.5-4.2), and overweight to obese (OR 3.7, 95% CI 3.1-4.3). Being obese or overweight in both pregnancies was associated with increased risk of preeclampsia in the second pregnancy. Women who increased their BMI from underweight to normal or overweight between pregnancies had risks of preeclampsia comparable with those with normal BMI in both pregnancies. African-American, but not white, women who had a reduction in BMI from obese or overweight to normal between pregnancies remained at increased risk for preeclampsia. CONCLUSION: Increases in prepregnancy BMI from normal weight to overweight or obese between pregnancies are associated with increased risk of preeclampsia in the subsequent pregnancy. LEVEL OF EVIDENCE: II.     

子痫前期患者胎盘早剥发病危险因素分析

目的 探讨子痫前期患者胎盘早剥发病的危险因素.方法 对1994年1月至2008年12月的15年间,在北京大学第三医院住院并分娩的219例患者的临床资料进行回顾性分析,根据病情分为3组:子痫前期早剥组,52例,为重度子痫前期发生胎盘早剥的患者;子痫前期组,130例,为重度子痫前期未发生胎盘早剥的患者;原因不明早剥组,37例,为非子痫前期发生胎盘早剥的患者.选择同期无并发症的正常分娩产妇178例为对照组(按1∶2病例对照研究方法选择).采用单因素及多因素回归分析方法,分析子痫前期患者胎盘早剥的发病危险因素.结果 (1)与对照组比较,单因素分析结果显示,孕次、产次、子痫前期病史、中晚期妊娠丢失史、自身免疫性疾病史、慢性高血压病史、此次孕期无规律产前检查、胎儿生长受限(FGR)及脐动脉收缩期最大血流速度(S)与舒张末期血流速度(D)的比值(S/D)异常是子痫前期患者胎盘早剥发病的危险因素;多因素回归分析显示,孕期无规律产前检查(OR=45.348,95%CI为17.096～120.288,P=0.000)、FGR(OR=27.087,95%CI为5.585～131.363,P=0.000)及中晚期妊娠丢失史(OR=16.068,95% CI为1.698～152.029,P=0.015)是子痫前期患者胎盘早剥发病的独立危险因素.(2)与子痫前期组比较,子痫前期病史(OR=3.715,95% CI为1.096～12.596,P=0.035)及孕期无规律产前检查(OR=2.509,95%CI为1.173～5.370,P=0.018)是子痫前期患者胎盘早剥发病的独立危险因素.结论 孕期无规律产前检查、子痫前期病史、中晚期妊娠丢失史及FGR是影响子痫前期患者胎盘早剥发病的危险因素.     

Maternal complications and perinatal outcomes associated with gestational hypertension and severe preeclampsia in Taiwanese women.

BACKGROUND/PURPOSE: The role of proteinuria in disease severity of preeclampsia and gestational hypertension has not been determined. The objective of this study was to compare the effects of disease severity on maternal complications and pregnancy outcome between women with severe preeclampsia and women with gestational hypertension. METHODS: A retrospective case-control study using daily records from the birth registry for the years 1994 to 2003 was conducted. Cases (n = 364) were defined as women with severe preeclampsia. Controls (n = 249) were selected from women with gestational hypertension. The outcome measures were maternal complications and perinatal-related factors. RESULTS: Women with severe preeclampsia had an increased risk of intrauterine growth restriction (adjusted odds ratio [aOR], 2.16; 95% confidence interval [CI], 1.10-4.24; p = 0.026). Risk factors associated with severe preeclampsia patients were lack of prenatal care (aOR, 2.95; 95% CI, 1.45-5.99), systolic blood pressure >or= 180 mmHg (aOR, 14.3; 95% CI, 1.69-121.0), and diastolic blood pressure >or= 105mmHg (aOR, 21.2; 95% CI, 6.99-64.3) compared with women with gestational hypertension in Model I. When we added proteinuria as a variable, two significant risk factors, diastolic blood pressure >or= 105mmHg (aOR, 18.2; 95% CI, 4.85-68.3) and significant proteinuria (aOR, 1.01; 95% CI, 1.006-1.014), were associated with severe preeclampsia patients in Model II. A subgroup of women with gestational hypertension and proteinuria had an increased risk of placental abruption (unadjusted OR, 4.36; 95% CI, 1.05-18.1) and disseminated intravascular coagulation (unadjusted OR, 6.46; 95% CI, 1.05-39.8). Finally, maternal complications (aOR, 2.59; 95% CI, 1.34-5.04) became the single significant factor associated with gestational hypertension and proteinuria. CONCLUSION: Proteinuria may play a role in the progression of gestational hypertension to severe forms of preeclampsia associated with subsequent maternal complications and extremely-low-birth-weight babies.     

Previous history of surgically induced abortion and complications of the third stage of labour in subsequent normal vaginal deliveries

Objective. To estimate the risk of complications of the third stage of labour needing manual revision of uterine cavity or curettage in deliveries following one or multiple induced abortions in nulliparous women who had singleton live births in Estonia in 1994–2002.

Methods. Registry study using the data from the Estonian medical birth registry: 32,652 women had not had any abortions, 7333 women had had one and 2383 women had had two or more surgically induced abortions before their first delivery. Multiple logistic regression analysis was performed to estimate crude odds ratios (OR), adjusted ORs and their 95% confidence intervals, with women having had no abortions as the reference group. Adjustment was made for maternal age, sex and weight of infant, labour induction/augmentation.

Results. In the single abortion group, the crude OR was 1.25 (95% confidence intervals (CI) 1.12–1.40), the adjusted OR was 1.23 (95% CI 1.10–1.38); in the multiple abortion group the crude OR was 1.28 (95% CI 1.06–1.53), the adjusted OR was 1.24 (95% CI 1.03–1.49).

Conclusions. Our findings suggest a positive association between one or more first trimester abortion(s) and the risk of complications in the third stage of labour in subsequent singleton delivery.     

Family history of early-onset cardiovascular disorders is associated with a higher risk of severe preeclampsia

AIM: The aim was to evaluate familial early-onset cardiovascular disorders as potential risk factors for severe preeclampsia. STUDY DESIGN: A case-control study was carried out by interviewing 162 primiparous severely preeclamptic women and 521 primiparous healthy control patients after delivery to determine the frequency of cardiovascular disorders (chronic hypertension, myocardial infarction, stroke) developed before the age of 50 among their parents. The chi2-test was utilized to estimate odds ratios (OR) and 95% confidence intervals (95% CI). The association was adjusted for pre-pregnancy body mass index, maternal age, and smoking habits before pregnancy using logistic regression analysis. RESULTS: Maternal and paternal early-onset chronic hypertension (adjusted OR: 3.84, 95% CI: 2.25-6.54; and adjusted OR: 3.26, 95% CI: 1.76-6.05) as well as paternal early-onset myocardial infarction (adjusted OR: 3.33; 95% CI: 1.51-7.32) were independent risk factors for severe preeclampsia. Early-onset stroke affected only the fathers of severely preeclamptic patients. Among the severely preeclamptic patients a positive family history of cardiovascular disorders developed before the age of 50 increased the risk of early-onset preeclampsia (developing before the 32nd gestational week) by 5.05-fold (95% CI: 3.08-8.31) compared with the control group. CONCLUSION: Our results suggest that the presence of familial early-onset cardiovascular disorders is a predisposing factor for severe preeclampsia.     

Maternal asthma and risk of preeclampsia: a case-control study

OBJECTIVE: To quantify the associations between asthma characteristics and the risk of preeclampsia. STUDY DESIGN: In this case-control study, asthma history among 286 preeclampsia cases and 470 normotensive controls in Seattle was assessed by postpartum interview and medical record abstraction. OR and 95% CI were estimated using logistic regression. The sample size was adequate to detect unadjusted asthma history with ORs of > or =1.6 at a power of 80%. RESULTS: After adjustment, women with a history of prepregnancy asthma diagnosis were not at increased preeclampsia risk (OR 0.94, 95% CI 0.58-1.52). Women experiencing asthma symptoms during pregnancy were more likely than pregnant nonasthmatics to have preeclampsia (OR 2.20, 95% CI 0.79-6.10). Those with long-term pre-pregnancy asthma and symptoms during pregnancy were at particularly increased risk (OR 9.09, 95% CI 1.02-81.6). Point estimates were generally higher after restriction to women withfull-term deliveries. CONCLUSION: This analysis suggests that asthmatics, particularly those who are symptomatic during pregnancy, may be at higher risk of developing preeclampsia.     

Recurrent preeclampsia and perinatal outcome: a study of women with recurrent preeclampsia compared with women with preeclampsia who remained normotensive during their prior pregnancies

OBJECTIVE: To evaluate the impact of preeclampsia recurrence on perinatal outcome. MATERIALS AND METHODS: A case-controlled study was performed in multiparous women who developed preeclampsia in index pregnancy (n = 64). Among these, women who had preeclampsia in previous pregnancies (n = 21) were compared to those who remained normotensive during their prior pregnancies (n = 43). Maternal and fetal variables were compared. Multivariate logistic analyses were performed to examine the impact of preeclampsia recurrence on fetal loss, preterm delivery, small for gestational age (SGA) occurrence and respiratory distress syndrome adjusted for confounding variables. RESULTS: No statistical significant difference was observed between the two groups in terms of age, delivery weeks, steroid use and laboratory markers. Fetal loss was higher in women with recurrent preeclampsia (19.0%) than in women with preeclampsia who had a normotensive pregnancy history (4.7%), with adjusted odds ratio (OR) of 5.77 [95% confidence interval (CI) 0.84-39.54]. CONCLUSION: Women with recurrent preeclampsia had a higher rate of perinatal loss compared to women with preeclampsia who were normotensive in their prior pregnancies.     

Depression and anxiety in early pregnancy and risk for preeclampsia

OBJECTIVE: To examine whether depression and anxiety in early pregnancy are associated with preeclampsia in an unselected nulliparous population. METHODS: In this prospective population-based study during pregnancy at outpatient maternity clinics in the Helsinki metropolitan area, depression was assessed by a Finnish modification of the short form of the Beck Depression Inventory and anxiety by one established question. Preeclampsia was defined as elevated blood pressure (BP) (more than 140/100 mmHg) and proteinuria (0.3 g during 24 hours or more). Age, smoking, alcohol consumption, marital status, socioeconomic status, and bacterial vaginosis were analyzed as potentially confounding factors in a multiple logistic regression analysis. RESULTS: Six hundred twenty-three consecutive nulliparous women with singleton pregnancies were studied at ten to 17 (median 12) weeks' gestation and at delivery. Of them, 28 (4.5%) women developed preeclampsia. Depression (mean Beck score 4.5, range 3-17) was observed in 185 (30%), women and anxiety was observed in 99 (16%) in early pregnancy. In multivariate analysis, after adjustment for potentially confounding factors, depression was associated with increased risk (odds ratio [OR] 2.5; 95% confidence interval [CI] 1.1, 5.4) for preeclampsia, as was anxiety (OR 3.2; 95% CI 1.4, 7.4). Either depression or anxiety, or both, were associated with increased risk (OR 3.1; 95% CI 1.4, 6.9) for preeclampsia. Bacterial vaginosis together with depression was associated with increased risk (OR 5.3; 95% CI 1.8, 15.0) for preeclampsia. CONCLUSION: Depression and anxiety in early pregnancy are associated with risk for subsequent preeclampsia, a risk further increased by bacterial vaginosis.     

Risk of preeclampsia in relation to maternal history of migraine headaches.

OBJECTIVE: We examined the relationship between migraines and preeclampsia risk. STUDY DESIGN: Cases were 244 women with preeclampsia and controls were 470 normotensive women. Women were asked if a physician had ever told them that they had migraines. Odds ratios (OR) and 95% confidence intervals (CI) were calculated. RESULTS: A history of migraines was associated with a 1.8-fold increased risk of preeclampsia (95% CI 1.1-2.7). Women who were 30+ years old when diagnosed with migraines had the highest risk (OR 2.8, 95% CI 0.8-9.0). The migraine-preeclampsia association appeared to be modified by pre-pregnancy overweight status (p = 0.06). Overweight migrainous women, compared with lean nonmigrainous women, had a 12-fold increased preeclampsia risk (95% CI 5.9-25.7). CONCLUSION: Our findings are consistent with reports from six of eight previous studies on the topic. Nevertheless, prospective cohort studies are needed to further evaluate the extent to which migraines and/or its treatments are associated with preeclampsia risk.     

Bishop score and risk of cesarean delivery after induction of labor in nulliparous women

OBJECTIVE: To quantify the risk and risk factors for cesarean delivery associated with medical and elective induction of labor in nulliparous women. METHODS: A prospective cohort study was performed in nulliparous women at term with vertex singleton gestations who had labor induced at 2 obstetrical centers. Medical and elective indications and Bishop scores were recorded before labor induction. Obstetric and neonatal data were analyzed and compared with the results in women with a spontaneous onset of labor. Data were analyzed using univariate and multivariable regression modeling. RESULTS: A total of 1,389 women were included in the study. The cesarean delivery rate was 12.0% in women with a spontaneous onset of labor (n = 765), 23.4% in women undergoing labor induction for medical reasons (n = 435) (unadjusted odds ratio [OR] 2.24; 95% confidence interval [CI] 1.64-3.06), and 23.8% in women whose labor was electively induced (n = 189) (unadjusted OR 2.29; 95% CI 1.53-3.41). However, after adjusting for the Bishop score at admission, no significant differences in cesarean delivery rates were found among the 3 groups. A Bishop score of 5 or less was a predominant risk factor for a cesarean delivery in all 3 groups (adjusted OR 2.32; 95% CI 1.66-3.25). Other variables with significantly increased risk for cesarean delivery included maternal age of 30 years or older, body mass index of 31 or higher, use of epidural analgesia during the first stage of labor, and birth weight of 3,500 g or higher. In both induction groups, more newborns required neonatal care, more mothers needed a blood transfusion, and the maternal hospital stay was longer. CONCLUSION: Compared with spontaneous onset of labor, medical and elective induction of labor in nulliparous women at term with a single fetus in cephalic presentation is associated with an increased risk of cesarean delivery, predominantly related to an unfavorable Bishop score at admission. LEVEL OF EVIDENCE: II-2.     

Risk factors associated with preterm (<37+0 weeks) and early preterm birth (<32+0 weeks): univariate and multivariate analysis of 106?345 singleton births from the 1994 statewide perinatal survey of Bavaria

Objective: The study was conducted to identify medical, obstetrical and social risk factors associated with early preterm births (<32 + 0 gestational weeks). Study design: The Statewide Perinatal Survey of Bavaria is a collection of perinatal data from all Bavarian maternity units using a uniform numbered questionnaire. Data on 106 345 singleton births from the 1994 Survey were analysed using univariate and multivariate logistic regression analysis. Results: In the multivariate analysis, early preterm birth was associated with premature rupture of the membranes (odds ratio (OR) 1.6, 95% confidence interval (CI) 1.37-1.86), treatment for infertility (OR 1.7, 95% CI 1.19-2.34), previous induced abortion (OR 1.8, 95% CI 1.57-2.13), maternal age>35 years (OR 1.8, 95% CI 1.47-2.16), premature cervical dilatation (OR 2.3, 95% CI 1.86-2.94), a history of stillbirth (OR 3.2, 95% CI 2.13-4.83), a history of preterm birth (OR 3.3, 95% CI 2.45-4.48), maternal age <18 years (OR 3.4, 95% CI 2.03-5.61), malpresentation (OR 3.9, 95% CI 3.10-4.93), preeclampsia (OR 4.0, 95% CI 3.20-4.94), uterine bleeding (OR 5.0, 95% CI 4.08-6.02), preterm labour (OR 7.0, 95% CI 5.94-8.22), and chorioamnionitis (OR 22.3, 95% CI 17.40-28.66). Conclusion: These data identify a subgroup of women at an increased risk for early preterm birth and may benefit from an intensified prenatal care. Risk factors related to the obstetrical history, genital infections, preeclampsia and maternal age are the most relevant for early preterm birth.     

Preventing preeclampsia and its fetal complications with low-dose aspirin in East Asians and non-East Asians:A systematic review and meta-analysis

Background: Low-dose aspirin can reduce the incidence of preeclampsia and intrauterine growth restriction (IUGR). However, the effects of ethnicity upon low-dose aspirin’s efficacy has not been analyzed. Here, we comparatively evaluated the efficacy of low-dose aspirin in preventing preeclampsia and related fetal complications in East Asian and non-East Asian pregnant women at risk for preeclampsia. Methods: Several databases were searched for randomized controlled trials (RCTs) comparing low-dose aspirin with either placebo or no treatment in pregnant women at risk for preeclampsia. Odds ratios (ORs) and associated 95% confidence intervals (CIs) for preeclampsia and related fetal outcomes were tabulated. Results: Low-dose aspirin significantly reduced preeclampsia risk in both East Asians (OR = 0.20, 95% CI: 0.11–0.35) and non-East Asians (OR = 0.84, 95% CI: 0.77–0.92). Low-dose aspirin significantly reduced IUGR risk in East Asians (OR = 0.36, 95% CI: 0.20–0.67) but not in non-East Asians (OR = 0.85, 95% CI: 0.41–1.77). Low-dose aspirin did not significantly reduce the risk of cesarean section in either East Asians (OR = 0.67, 95% CI: 0.14–3.22) or non-East Asians (OR = 1.01, 95% CI: 0.86–1.19). Conclusions: Low-dose aspirin is effective in reducing preeclampsia risk in both East Asians and non-East Asians and has differential effects in East Asians and non-East Asians with respect to IUGR.     

Increased risk of preeclampsia among nulliparous pregnant women with idiopathic hematuria

OBJECTIVE: Our purpose was to determine the risk of preeclampsia and gestational hypertension among nulliparous pregnant women with idiopathic hematuria. STUDY DESIGN: We conducted a prospective cohort study using data from the trial of Calcium for Preeclampsia Prevention (CPEP). Participants were followed up from screening and enrollment (gestational weeks 11-21) throughout pregnancy. Our analysis was limited to women who had been followed up to at least 20 weeks' gestation, had outcome information available, and were not suspected to have had urolithiasis. Surveillance for hematuria was conducted with dipsticks on clean-catch urine specimens obtained at research clinic visits. Idiopathic hematuria was defined as hematuria identified at regularly scheduled clinic visits in the absence of urinary tract infection and before the onset of labor. Logistic regression was used to estimate the risk of preeclampsia among women with hematuria compared with women without hematuria. RESULTS: Among the 4307 women available for analysis, 132 (3%) had idiopathic hematuria during pregnancy. Idiopathic hematuria was associated with an almost 2-fold increased odds for development of preeclampsia (adjusted odds ratio [aOR] = 1.89, 95% CI 1.12- 3.18) but not with increased odds of gestational hypertension (aOR = 0.78, 95% CI 0.46-1.32). CONCLUSIONS: Idiopathic hematuria identified during pregnancy is associated with greater risk of preeclampsia but not gestational hypertension.