Maternal use of oral contraceptives and risk of hypospadias – a population-based case-control study

The aim of this population-based case-control study was to examine the risk of isolated hypospadias in boys born to mothers who have used oral contraceptives in early pregnancy. The study was based on data from the Hungarian Case-Control Surveillance of Congenital Abnormalities from 1980 to 1996, and included 3,038 boys with hypospadias (cases), 24,799 boys without congenital abnormalities (CA-free controls), and 11,881 boys with abnormalities other than hypospadias. We used unconditional logistic regression to adjust for birth order, maternal age, maternal employment status, maternal diabetes, and pre-eclampsia. When comparing cases with CA-free controls the OR for maternal use of OC was 1.21 (95% CI: 0.67–2.17). When comparing cases with boys with other abnormalities, the OR for maternal use of OC was 0.83 (95% CI: 0.46–1.50). Our data showed that self-reported maternal use of oral contraceptives during pregnancy was not associated with an increased risk of hypospadias in the offspring.     

Hypospadias and maternal exposures to cigarette smoke

The few previous studies of hypospadias and smoking have suggested either no association or a reduced risk. This study, which uses data from the National Birth Defects Prevention Study, a multi-state, population-based case-control study, includes data on males born with severe hypospadias (i.e. the urethra opens at the penile shaft, scrotum or perineum) from 1997 to 2000. Non-malformed, liveborn male controls were selected randomly from birth certificates or from birth hospitals. Maternal interviews were completed by telephone with 453 case mothers and 1267 control mothers. Maternal smoking was not associated with hypospadias risk. For example, during the third month of pregnancy, smoking < 0.5 pack/day had an odds ratio (OR) of 1.1 [95% CI 0.6, 1.9]; 0.5 pack/day, 0.6 [0.4, 1.1]; and > or = 1 pack/day, 0.8 [0.4, 1.6]. Exposure to any secondhand smoke at home during the third month of pregnancy showed an OR of 0.6 [95% CI 0.4, 1.0], and exposure at work or school, an OR of 0.7 [0.5, 1.1]. Similar risks were observed for other months during the periconceptional period, and adjustment for several potential confounders did not substantially alter results. This analysis does not confirm a recent report suggesting that maternal smoking is associated with a reduced risk of having offspring with hypospadias.     

Maternal, delivery, and perinatal characteristics associated with cryptorchidism: a population-based case-control study among births in Washington State

BACKGROUND: The etiology of cryptorchidism is largely unknown. To identify maternal, perinatal, and delivery characteristics associated with cryptorchidism at birth, we conducted a population-based case-control study using Washington State birth certificates linked to birth hospitalization records. METHODS: We identified 2,395 cases of cryptorchidism among male infants born in Washington State during 1986-1996, and, for comparison, we randomly selected four controls per case (N = 9,580), frequency-matched by year of birth. RESULTS: Infant characteristics associated with cryptorchidism included low birth weight (OR = 1.5; 95% CI = 1.3-1.8), small size for gestational age (OR = 1.9; 95% CI = 1.6-2.2), and breech presentation (OR = 1.7; 95% CI = 1.4-2.1). In addition to cryptorchidism, cases were more likely to have another type of congenital malformation (OR = 3.7; 95% CI = 3.2-4.2), particularly digestive (OR = 6.8; 95% CI = 3.7-12.7) or genitourinary (OR = 4.1; 95% CI = 3.0-5.6). Maternal and pregnancy characteristics associated with cryptorchidism included nulliparity (OR = 1.2; 95% CI = 1.1-1.3), maternal smoking during pregnancy (OR = 1.2; 95% CI = 1.1-1.4), and the following pregnancy complications: oligohydramnios (OR = 1.8; 95% CI = 1.3-2.6), placental abnormality (OR = 1.3; 95% CI = 1.0-1.8), and pregnancy-induced hypertension (OR = 1.6; 95% CI = 1.4-1.9). Odds ratios were similar when the analysis was restricted to term infants. CONCLUSIONS: These findings suggest that factors affecting fetal growth and development may increase the risk of cryptorchidism.     

尿道下裂危险因素的病例对照研究

目的 探讨尿道下裂病因。方法 采用以医院为基础的1:2配比的病例对照研究方法,以统一的调查表及调查方式对107倒尿道下裂及214例对照进行面对面问卷调查,应用SAS 6.12软件对所有调查因素进行单因素及多因素logistic回归分析。结果 胎儿尿道下裂的发生与母亲孕前自然流产史(OR=3.87,95％CI:1.60～9.39)、孕期发生先兆流产(OR=3.57,95％CI:1.31～9.64)、孕早期感冒伴发热(OR=7.63,95％CI:2.50～23.24)、孕中期用抗感染和/或解热止痛药(OR=16.46,95％CI;3.46～78.21)、父亲职业性接触农药(OR=3.70,95％CI:1.49～9.16)及胎儿低出生体重(OR=12.62,95％CI:2.97～53.67)呈正相关,与母亲孕早期增加蛋白质类营养(OR=0.33,95％CI:O.15～0.74)呈负相关。结论 母亲孕前自然流产史、孕期发生先兆流产、孕早期感冒伴发热、孕中期用抗感染和/或解热止痛药、父亲职业性接触农药、胎儿低出生体重等可能增加胎儿发生尿道下裂的危险,而母亲孕早期增加蛋白质类营养可能降低胎儿发生尿道下裂的危险。     

Nutritional factors and hypospadias risks

Carmichael SL, Ma C, Feldkamp ML, Munger RG, Olney RS, Botto LD, Shaw GM, Correa A. Nutritional factors and hypospadias risks. Paediatric and Perinatal Epidemiology 2012; ?? : ??–??. Background: We examined whether hypospadias was associated with several aspects of the diet, including intake of animal products, intake of several nutrients and food groups related to a vegetarian diet and oestrogen metabolism, and diet quality. Methods: The study included deliveries from 1997 to 2005 that were part of the National Birth Defects Prevention Study. Diet was assessed by food frequency questionnaire during maternal telephone interviews, and two diet quality indices were developed based on existing indices. Analyses included 1250 cases with second‐ or third‐degree hypospadias (urethra opened at the penile shaft, scrotum or perineum) and 3118 male, liveborn, non‐malformed controls. All odds ratios (OR) and 95% confidence intervals [CI] were estimated from logistic regression models that included several potential confounders, including energy intake. Results: Intake of animal products was not associated with hypospadias; for example, the adjusted OR for any vs. no intake of meat was 1.0 [95% CI 0.6, 1.6]. Frequency of intake of meat or other animal products was also not associated with hypospadias, nor was intake of iron or several nutrients that are potentially related to oestrogen metabolism. Diet quality was also not associated with hypospadias; the OR for diet quality in the highest vs. lowest quartile for the two diet quality indices were 1.0 [95% CI 0.6, 1.6] and 0.9 [95% CI 0.7, 1.1]. Conclusion: This large study does not support an association of a vegetarian diet or worse diet quality with hypospadias.     

Maternal reproductive and demographic characteristics as risk factors for hypospadias

This study examined the association of hypospadias risk with several maternal reproductive and demographic characteristics: age, parity, body mass index (BMI), nausea and vomiting of pregnancy (NVP), multiple pregnancy, fertility treatments and procedures, education and race-ethnicity. The study included data on deliveries with estimated due dates from October 1997 to December 2000 that were part of the National Birth Defects Prevention Study, a multi-state case-control study of many birth defects. The analysis included 502 cases with second or third degree hypospadias (i.e. the urethra opened at the penile shaft, scrotum or perineum) and 1286 male, liveborn, non-malformed controls. Risks were estimated from a multivariable logistic regression model that included all exposures of interest. Results indicated particularly elevated risks among births to women who were primiparae, aged >or=35 years and had a BMI of >26, compared with women who were multiparae, aged <30 years and had a BMI of 相似文献   

Maternal diet and the risk of hypospadias and cryptorchidism in the offspring

Male genital tract birth defects have been associated in previous studies with several prenatal exposures to environmental and dietary risk factors. The purpose of this study was to explore the association between hypospadias and cryptorchidism, and the dietary habits of an agricultural population in Italy. A population-based case-control study was conducted in the Sicilian Province of Ragusa. Cases (n = 90) and controls (n = 202) included births for the period 1998-2002. Data on dietary habits of the mothers, as well as health-related social, occupational and environmental exposures prior to and during the index birth, were collected through interviews. Adjusted odds ratios (OR) were calculated by logistic regression after adjustment for confounding variables. Increased ORs were observed for mothers of children with hypospadias who, during pregnancy, frequently consumed fish (OR = 2.33 [95% confidence interval (CI) 1.03, 5.31]) and market-purchased fruit (OR = 5.10 [95% CI 1.31, 19.82]). For cryptorchidism, increased risk was observed in mothers consuming liver (OR = 5.21 [95% CI 1.26, 21.50]), and smoked products (OR = 2.46 [95% CI 1.15, 5.29]). For the two malformations pooled together, increased risk was associated with maternal consumption of liver (OR = 4.38 [95% CI 1.34, 14.26]) and with frequent consumption of wine (OR = 1.98 [95% CI 1.01, 3.86]). This study suggests that some maternal dietary factors may play a role in the development of congenital defects of the male reproductive tract. In particular, our data indicate that further research may be warranted on the endocrine-disrupting effects resulting from the bioaccumulation of contaminants (fish, liver), pesticides (marketed fruit, wine) and/or potentially toxic food components (smoked products, wine, liver).     

Perinatal risk factors for infantile autism

BACKGROUND: Etiologic hypotheses in infantile autism suggest a strong genetic component, as well as possible environmental risks linked to early fetal development. We evaluated the association of maternal, pregnancy, delivery, and infant characteristics and risk of infantile autism. METHODS: We conducted a case-control study nested within a population-based cohort (all Swedish children born in 1974-1993). We used prospectively recorded data from the Swedish Birth Register, which were individually linked to the Swedish Inpatient Register. Cases were 408 children (321 boys and 87 girls) discharged with a main diagnosis of infantile autism from any hospital in Sweden before 10 years of age in the period 1987-1994, plus 2,040 matched controls. Conditional logistic regression was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: The risk of autism was associated with daily smoking in early pregnancy (OR = 1.4; CI = 1.1-1.8), maternal birth outside Europe and North America (OR = 3.0; CI = 1.7-5.2), cesarean delivery (OR = 1.6; CI = 1.1-2.3), being small for gestational age (SGA; OR = 2.1; CI = 1.1-3.9), a 5-minute Apgar score below 7 (OR = 3.2, CI = 1.2-8.2), and congenital malformations (OR = 1.8, CI = 1.1-3.1). No association was found between autism and head circumference, maternal diabetes, being a twin, or season of birth. CONCLUSIONS: Our findings suggest that intrauterine and neonatal factors related to deviant intrauterine growth or fetal distress are important in the pathogenesis of autism.     

Maternal smoking during pregnancy and the risk of congenital urinary tract anomalies.

To study maternal smoking during pregnancy and the risk of congenital urinary tract anomalies, we interviewed mothers of 118 affected infants born to residents of western Washington State during 1990 and 1991 and mothers of 369 control infants randomly selected from those without birth defects delivered during those years in five hospitals in King County, Washington. Maternal smoking was associated with an increased risk of congenital urinary tract anomalies in offspring (adjusted odds ratio [OR] = 2.3; 95% confidence interval [CI] = 1.2, 4.5). This risk was higher among light smokers (1-1000 cigarettes during the pregnancy) (OR = 3.7; 95% CI = 1.7, 8.6) than among heavy smokers (OR = 1.4; 95% CI = 0.6, 3.3). Our results corroborate previous findings and support the hypothesis of a causal relation.     

Vitamin C and the risk of preeclampsia--results from dietary questionnaire and plasma assay

BACKGROUND: Oxidative stress plays an important role in the pathophysiology of preeclampsia. METHODS: In a case-control study of 109 women with preeclampsia and 259 controls, maternal dietary and plasma vitamin C in relation to preeclampsia risk were assessed. Dietary intake during the periconceptional period and pregnancy was ascertained using a semiquantitative food frequency questionnaire. Logistic regression procedures were used to derive odds ratios (OR) and 95% confidence intervals (CI). Plasma ascorbic acid was determined using automated enzymatic procedures. RESULTS: After adjusting for maternal age, parity, prepregnancy body mass index, and energy intake, women who consumed <85 mg of vitamin C daily (below the recommended dietary allowance), as compared with others, experienced a doubling in preeclampsia risk (OR = 2.1; 95% CI = 1.1-3.9). The OR for extreme quartiles of plasma ascorbic acid (<42.5 vs > or = 63.3 micromol/liter) was 2.3 (95% CI = 1.1-4.6). Compared with women in the highest quartile, those with plasma ascorbic acid <34.6 micromol/liter (lowest decile) experienced a 3.8-fold increased risk of preeclampsia (95% CI = 1.7-8.8). CONCLUSIONS: Our results, if confirmed, would suggest that current public health efforts to increase intake of fruits and vegetables rich in vitamin C and other antioxidants may reduce the risk of preeclampsia.     

Agricultural pesticide use and hypospadias in eastern Arkansas

INTRODUCTION: We assessed the relationship between hypospadias and proximity to agricultural pesticide applications using a GIS-based exposure method. METHODS: We obtained information for 354 cases of hypospadias born between 1998 and 2002 in eastern Arkansas; 727 controls were selected from birth certificates. We classified exposure on pounds of pesticides (estimated by crop type) applied or persisting within 500 m of each subject's home during gestational weeks 6 to 16. We restricted our analyses to 38 pesticides with some evidence of reproductive, developmental, estrogenic, and/or antiandrogenic effects. We estimated timing of pesticide applications using crop phenology and published records. RESULTS: Gestational age at birth [odds ratio (OR) = 0.91; 95% confidence interval (CI), 0.83-0.99], parity (OR = 0.79; 95% CI, 0.65-0.95), and delaying prenatal care until the third trimester (OR = 4.04; 95% CI, 1.46-11.23) were significantly associated with hypospadias. Risk of hypospadias increased by 8% for every 0.05-pound increase in estimated exposure to diclofop-methyl use (OR = 1.08; 95% CI, 1.01-1.15). Pesticide applications in aggregate (OR = 0.82; 95% CI, 0.70-0.96) and applications of alachlor (OR = 0.56; 95% CI, 0.35-0.89) and permethrin (OR = 0.37; 95% CI, 0.16-0.86) were negatively associated with hypospadias. CONCLUSIONS: Except for diclofop-methyl, we did not find evidence that estimated exposure to pesticides known to have reproductive, developmental, or endocrine-disrupting effects increases risk of hypospadias. Further research on the potential effects of exposure to diclofop-methyl is recommended.     

Ethnic-cultural background, maternal body size and pregnancy outcomes in a diverse Swiss cohort

OBJECTIVE: To investigate the influence of ethnic-cultural background and maternal body size on pregnancy outcomes in infants born at term. STUDY DESIGN: A retrospective cohort of 1,432 pregnant women who delivered a live newborn at term between 1999 and 2003 provided the data for the following study. We performed multivariable regression analyses for birth weight and rate of caesarean section controlling for body mass index (BMI), net weight gain, maternal age, parity, smoking, marital status and sex of infant. RESULTS: Thirty percent of the women studied had a BMI > or = 25; the proportion of mothers with a BMI > or = 25 varied substantially by ethnic-cultural background (range: Far East 2.8% vs. Africa 50.0%). After adjustment for confounding variables, mothers from Sri Lanka and the Middle East had significantly lighter infants (Sri Lanka -145.5 g, 95% CI -59.3 g to -231.7 g, P = 0.001; Middle East -214.3 g, 95% CI -33.7 g to -395.0 g, P = 0.02) than mothers from Switzerland. Each unit increase in maternal pre-pregnancy BMI was associated with a 20.3 g increase in birth weight (95% CI 14.3 g to 26.4 g, P < 0.001). Muslim mothers from the former Yugoslavia had significantly lower odds of caesarean section than Swiss mothers (OR 0.63, 95% CI 0.41 to 0.96, P = 0.03). CONCLUSIONS: In this cohort, certain ethnic-cultural groups had increased odds for low birth weight and others had reduced odds of operative delivery compared with the Swiss comparison group. Given the strong association between ethnic-cultural background and overweight in this cohort, culturally appropriate support and counseling during prenatal care should be evaluated in the increasingly diverse environment in European countries.     

Low preconception body mass index is associated with birth outcome in a prospective cohort of Chinese women

Low maternal prepregnancy BMI is associated with adverse birth outcomes, but the BMI at which risk increases is not well defined. We assessed whether the relationship between prepregnancy BMI and birth outcomes is influenced by the extent to which mothers were underweight in a prospective study in Anhui, China. The women (n = 575) were 20-34 y old, married, nulliparous and nonsmokers. All measures of infant growth increased with increasing maternal BMI until a plateau was reached at a BMI of 22-23 kg/m2. Infants born to the 27% of women who were severely underweight before pregnancy (BMI < or = 18.5 kg/m2) were at increased risk for fetal growth deficits associated with infant morbidity. Compared with a normal BMI, being severely underweight was associated with mean (+/- SEM) reductions of 219 +/- 40 g in infant birthweight and 6.7 +/- 1.3% in the birthweight ratio and an 80% increase in risk of intrauterine growth restriction [odds ratio (OR) 1.8; 95% CI: 1.0, 3.3; P = 0.05]. Being severely underweight was also associated with smaller infant head circumference and lower ponderal index. Being moderately underweight (18.5 < BMI < 19.8 kg/m2) was not significantly associated with adverse pregnancy outcomes. Gestational age and risk of preterm birth were not associated with maternal BMI. More than half of the women in this study were underweight before pregnancy. Although being moderately underweight was not associated with increased risk of adverse pregnancy outcomes, being severely underweight was an important risk factor for reduced fetal growth.     

Adverse birth outcomes associated with open dumpsites in Alaska Native Villages

This retrospective cohort study evaluated adverse birth outcomes in infants whose birth records indicated maternal residence in villages containing dumpsites potentially hazardous to health and environment. Birth records from 1997 to 2001 identified 10,073 eligible infants born to mothers in 197 Alaska Native villages. Outcomes included low or very low birth weight, preterm birth, and intrauterine growth retardation. Infants from mothers in villages with intermediate (odds ratio (OR) = 1.73, 95% confidence interval (CI): 1.06, 2.84) and high (OR = 2.06, 95% CI: 1.28, 3.32) hazard dumpsites had a higher proportion of low birth weight infants than did infants from mothers in the referent category. More infants born to mothers from intermediate (OR = 4.38, 95% CI: 2.20, 8.77) and high (OR = 3.98, 95% CI: 1.93, 8.21) hazard villages suffered from intrauterine growth retardation. On average, infants weighed 36 g less (95% CI: -71.2, -0.8) and 55.4 g less (95% CI: -95.3, -15.6) when born to highly exposed mothers than did infants in the intermediate and low exposure groups, respectively, an effect even larger in births to Alaska Native mothers only. No differences in incidence were detected across exposure levels for other outcomes. This is the first study to evaluate adverse pregnancy outcomes associated with open dumpsites in Alaska Native villages.     

舟山市2002-2015年出生体重变化与不良出生结局及影响因素分析

目的 描述舟山市2002-2015年新生儿出生体重变化,分析不良出生结局的发生率及影响因素。方法 利用舟山市电子医疗数据库,收集孕产妇及新生儿的相关信息,描述新生儿出生体重和不良出生结局发生率的变化趋势,采用多元Logistic回归分析其影响因素。结果 37 141例新生儿的平均出生体重为（3 388±462） g,低出生体重儿、巨大儿、早产的发生率分别为2.34%,9.42%和3.61%;高危妊娠（OR=1.80,95%CI:1.42~2.28）是低出生体重儿的危险因素;出生季节为夏季、秋季、母亲年龄<25岁、孕前消瘦等是巨大儿的保护因素。母亲孕前超重和肥胖是巨大儿的危险因素;母亲年龄<25岁是早产发生的保护因素。母亲年龄>30岁（OR=1.38,95%CI:1.19~1.60）、冬季出生（OR=1.24,95%CI:1.06~1.45）、母亲孕前超重和肥胖、高危妊娠（OR=1.95,95%CI:1.66~2.29）等是早产的危险因素。结论 舟山市2002-2015年新生儿出生体重呈下降趋势,低出生体重儿和早产儿发生率呈上升趋势。新生儿性别、出生季节,母亲年龄、孕前体质指数（body mass index,BMI）、高危妊娠等因素影响低出生体重儿、巨大儿或早产儿的发生。     

Maternal obesity and infant heart defects

OBJECTIVE: This study determined whether obese women have an increased risk of cardiovascular defects in their offspring compared with average weight women. RESEARCH METHODS AND PROCEDURES: In a case-control study, prospectively collected information was obtained from Swedish medical health registers. The study included 6,801 women who had infants with a cardiovascular defect and, as controls, all delivered women (N = 812,457) during the study period (1992 to 2001). Infants with chromosomal anomalies or whose mothers had pre-existing diabetes were excluded. Obesity was defined as BMI >29 kg/m(2), and morbid obesity was defined as BMI >35 kg/m(2). Comparisons were made with average weight women (BMI = 19.8 to 26 kg/m(2)). RESULTS: In the group of obese mothers, there was an increased risk for cardiovascular defects compared with the average weight mothers [adjusted odds ratio (OR) = 1.18; 95% CI, 1.09 to 1.27], which was slightly more pronounced for the severe types of cardiovascular defects (adjusted OR = 1.23; 95% CI, 1.05 to 1.44). With morbid obesity, the OR for cardiovascular defects was 1.40 (95% CI, 1.22 to 1.64), and for severe cardiovascular defects, the OR was 1.69 (95% CI, 1.27 to 2.26). There was an increased risk for all specific defects studied among the obese women, but only ventricular septal defects and atrial septal defects reached statistical significance. DISCUSSION: In this sample, a positive association was found between maternal obesity in early pregnancy and congenital heart defects in the offspring. A suggested explanation is undetected type 2 diabetes in early pregnancy, but other explanations may exist.     

Physical exposures during pregnancy and congenital cardiovascular malformations

Congenital cardiovascular malformations (CCM) cause substantial neonatal morbidity and mortality. Known risk factors for CCM explain only 10-20% of all cases. Few studies have examined mothers' physical exposures during pregnancy and the risk of CCM in their offspring. This study examined the association between exposures to extreme temperatures, prolonged standing, and heavy lifting during early pregnancy and risk of CCM in offspring. Using a case-control study design, 502 cases and 1066 controls were drawn from the population of all liveborn infants born between January 1988 and June 1991 to mothers living in 14 counties in New York State. Cases were identified from a population-based registry of congenital malformations. Controls were randomly selected from birth certificate records. Interviews were conducted by telephone, using a structured questionnaire. Exposure estimates were based on women's self-reports of conditions in the residence and workplace. Eighty-three per cent of the mothers were white, and 66% were between 25 and 34 years old. After adjusting all results for known risk factors and confounding variables, we found no significant increased risk of CCM in subjects whose mothers reported being exposed during early pregnancy to extreme heat (OR = 1.13, 95% CI 0.59, 2.19), nor to extreme cold (OR = 1.19, 95% CI 0.66, 2.15). Mothers who reported ever using a hot tub, hot bath, or sauna during early pregnancy had no increased risk of CCM in their offspring (OR = 0.88, 95% CI 0.65, 1.18). Performing heavy lifting during early pregnancy did not increase the risk of CCM in offspring (OR = 0.80, 95% CI 0.57, 1.11). Prolonged standing during early pregnancy was not associated with an increased risk of CCM in children (OR = 1.03, 95% CI 0.82, 1.28). Thus if these maternal exposures have an adverse effect, it is unlikely to involve CCMs.     

Maternal age, exposure to siblings, and risk of amyotrophic lateral sclerosis

Between 1987 and 2005, the authors conducted a nested case-control study based on the Swedish Multi-Generation Register to investigate whether early life exposures, namely, maternal age at delivery and exposure to siblings, are associated with an increased risk of amyotrophic lateral sclerosis (ALS). The study comprised 768 ALS cases and five controls per case matched by birth year and gender. Odds ratios and their corresponding 95% confidence intervals for ALS were estimated by conditional logistic regression modeling. Low maternal age (< or =20 years) and high maternal age (> or =41 years) were both associated with higher risk of ALS (odds ratio (OR) = 1.5, 95% confidence interval (CI): 1.1, 2.0 and OR = 1.7, 95% CI: 1.1, 2.4, respectively). The relative risk of ALS increased slightly with increasing number of younger siblings (OR = 1.1, 95% CI: 1.0, 1.1; p = 0.02). Children whose first younger sibling was born after the age of 6 years had the greatest relative risk (OR = 1.8, 95% CI: 1.2, 2.7). Exposure to older siblings was not associated with the risk of ALS. Although the strength of the observed associations was modest, these results provided further support for the theory that early life exposures might contribute to the disease pathogenesis.     

Risk factors for early neonatal mortality

OBJECTIVE: To assess risk factors for early neonatal mortality. METHODS: A population-based case-control study was carried out with 146 early neonatal deaths and a sample of 313 controls obtained among survivals of the neonate period in the south region of the city of S?o Paulo, in the period of 8/1/2000 to 1/31/2001. Information was obtained through home interviews and hospital charts. Hierarchical assessment was performed in five groups with the following characteristics 1) socioeconomic conditions of mothers and families, 2) maternal psychosocial conditions, 3) obstetrical history and biological characteristics of mothers, 4) delivery conditions, 5) conditions of newborns RESULTS: Risk factors for early neonate mortality were: Group 1: poor education of household head (OR=1.6; 95% CI: 1.1;2.6), household located in a slum area (OR=2.0; 95% CI: 1.2;3.5) with up to one room (OR=2.2; 95% CI: 1.1;4.2); Group 2: mothers in recent union (OR=2.0; 95% CI: 1.0;4.2), unmarried mothers (OR=1.8; 95% CI: 1.1;3.0), and presence of domestic violence (OR=2.7; 95% CI: 1;6.5); Group 3: presence of complications in pregnancy (OR=8.2; 95% CI: 5.0;13.5), previous low birth weight (OR=2.4; 95% CI: 1.2;4.5), absence of pre-natal care (OR=16.1; 95% CI: 4.7;55.4), and inadequate pre-natal care (block 3) (OR=2.1; 95% CI: 2.0;3.5); Group 4: presence of clinical problems during delivery (OR=2.9; 95% CI: 1.4;5.1), mothers who went to hospital in ambulances (OR=3.8; 95% CI: 1.4;10.7); Group 5: low birth weight (OR=17.3; 95% CI: 8.4;35.6) and preterm live births (OR=8.8; 95% CI: 4.3;17.8). CONCLUSIONS: Additionally to proximal factors (low birth weight, preterm gestations, labor complications and unfavorable clinical conditions in gestation), the variables expressing social exclusion and presence of psychosocial factors were also identified. This context may affect the development of gestation and hinder the access of women to health services. Adequate prenatal care could minimize the effect of these variables.