Mode of delivery is associated with asthma and allergy occurrences in children

PURPOSE: A growing body of evidence indicates that perinatal factors modulate immune development and thereby may affect childhood asthma risk. In this study, we examined the associations between birth by cesarean section (C-section) and atopic disease occurrence in childhood. METHODS: Subjects were born in California between 1975 and 1987 and were 8 to 17 years old during their enrollment in the Children's Health Study. Our analysis was restricted to 3464 children born at or after 37 weeks of gestation with a birth weight of 2500 g or greater based on birth certificate data. Information about sociodemographic factors, reported physician-diagnosed asthma, and other atopic diseases was obtained by using a self-administered structured questionnaire. Logistic regression models were fitted to compute odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: Children born by C-section were at increased risk for asthma (OR, 1.33; 95% CI, 1.01-1.75), hay fever (OR, 1.57; 95% CI, 1.24-1.99), and allergy (OR, 1.26; 95% CI, 1.03-1.53) compared with those born vaginally. Risk associated with C-section was the same for children regardless of family history of asthma or allergy. CONCLUSION: We conclude that birth by C-section or processes associated with it may increase the risk for atopic disease in childhood.     

Perinatal and maternal risk factors for autism spectrum disorders in New South Wales, Australia

Background This study was commenced in 1999 with the aim of examining risk factors for autism using established population‐based data for comparison. Methods Cases were ascertained using active surveillance and compared with birth data. Results Four risk factors were found to be significantly associated with autism using binary logistic regression analysis; being male [adjusted odds ratio (OR) 4.7, 95% confidence interval (CI) 3.2–7.0], being born prematurely (adjusted OR 2.2, 95% CI 1.5–3.5), having maternal age ≥35 years (adjusted OR 1.7, 95% CI 1.2–2.4) and having a mother born outside Australia (adjusted OR 1.4, 95% CI 1.0–1.9). For analysis completed for pregnancies, rather than live births, multiple birth was also a significant risk factor for one or more children of the pregnancy to be affected by autism (adjusted OR 2.5, 95% CI 1.1–5.5). There was a statistically significant trend towards increasing risk with increasing risk factor ‘dose’ for gestational age (P = 0.019), multiple birth (P = 0.016) and maternal age (P < 0.001). For mother's country of birth the group with the highest risk were children of mother's born in south‐east or north‐east Asia. There was a non‐significant trend towards a higher proportion of children with developmental disability having risk factors. Conclusion Replication of risk factors from previous studies and a significant risk factor ‘dose’ effect add to growing evidence that maternal and perinatal factors are low magnitude risk factors for autism. The association between developmental disability and autism risk factors warrants further examination.     

Referral and delivery outcomes in Kivu,Democratic Republic of Congo

BACKGROUND: The process of referral between the first and the second level of the health system in the Democratic Republic of Congo is poorly understood. This report intends to study the association between the referral and the hospital perinatal outcomes. METHODS: Delivery outcomes in a retrospective cohort of 1162 women admitted between June 95 and May 96, in two referral hospitals in Kivu were analyzed according to the referral status and the women's characteristics. RESULTS: Forty-three percent (n=492)of women admitted, corresponding to 2.3% of expected pregnant women, were referred. Referred women had higher risks of obstetrical complications (OR=2.0; CI95%: 1.3-3.1) and intervention (OR=1.5; CI95%: 1.0-2.3) and similar risks of low birth weight and perinatal mortality. Women with complications during the antenatal period had a double risk of intervention and perinatal mortality. The risk of obstetrical intervention was lower when women had attended 2 visits (OR=0.5; CI95%: 0.3-0.8); the risk of low birth weight was lowest only for mothers who had attended one visit (OR=0.5; CI95%: 0.3-0.9). Distance > or =90 minutes walking from home to hospital raised the risk of obstetrical complication (OR=1.7; CI95%: 1.1-2.5), the risk of obstetrical intervention (OR=1.5; CI95%: 1.0-2.1), and the risk of perinatal mortality (OR=1.6; CI95%: 1.0-2.7). Late admission raised the risk of perinatal mortality (OR=1.8; CI95%: 1.2-2.9) and lowered the risk of obstetrical complication (OR=0.7; CI95%: 0.5-1.0). Part payment of care was associated with higher risks of low birth weight (OR=1.9; CI95%: 1.3-2.9), perinatal mortality (OR=2.2; CI95%: 1.4-3.5) and obstetrical intervention (OR=2.4; CI95%: 1.7-3.4). CONCLUSION: These results suggest a deficit of referred cases considering that 15% of pregnant women in the area covered by the referral hospitals should have been referred. They confirm the negative influence of economic and geographic constraints on the delivery outcomes. They point out the relevance of making reorganization of the referral system a priority.     

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.     

Perinatal factors and risk of neuroblastoma

Neuroblastoma is a malignancy commonly diagnosed during infancy or early childhood, raising speculation about the role of perinatal factors and risk of disease. Using a case-control design, cases included 155 infants and children aged 0-5 years with histologically confirmed neuroblastoma diagnosed and reported to the New York State Cancer Registry between 1976 and 1987. Controls were randomly selected from the State's Livebirth Registry and were frequency matched to cases on year of birth (n = 310). Medical records of cases were used to verify histology and stage of disease. Data on perinatal factors were ascertained from birth certificates and standardised telephone interviews with mothers. Unconditional logistic regression was used to estimate (un)adjusted odds ratios (OR) and 95% confidence intervals (CI). Both preterm (< 37 weeks) and post-term (> 42 weeks) birth were associated with a reduction in risk (OR = 0.4 [CI = 0.1, 0.9] and OR = 0.3 [CI = 0.1, 0.7] respectively) after controlling for confounders in unconditional logistic regression analysis. Elevated risk factors included: smoking during pregnancy (OR = 1.6; CI = 0.9, 2.8), contracted pelvis (OR = 2.3; CI = 0.6, 9.8), birth injury (OR = 2.9; CI = 0.3, 24.9) and 1-min Apgar Score < or =3 (OR = 6.0; CI = 0.9, 38.6); all confidence intervals included one. These data suggest that extremes in gestation may be associated with a reduced risk, although aetiological mechanisms remain unknown.     

Placental abruption and perinatal mortality in the United States

Placental abruption is an uncommon obstetric complication associated with high perinatal mortality rates. The authors explored the associations of abruption with fetal growth restriction, preterm delivery, and perinatal survival. The study was based on 7,508,655 singleton births delivered in 1995 and 1996 in the United States. Abruption was recorded in 6.5 per 1,000 births. Perinatal mortality was 119 per 1,000 births with abruption compared with 8.2 per 1,000 among all other births. The high mortality with abruption was due, in part, to its strong association with preterm delivery; 55% of the excess perinatal deaths with abruption were due to early delivery. Furthermore, babies in the lowest centile of weight (<1% adjusted for gestational age) were almost nine times as likely to be born with abruption than those in the heaviest (> or =90%) birth weight centiles. This relative risk progressively declined with higher birth weight centiles. After controlling for fetal growth restriction and early delivery, the high risk of perinatal death associated with abruption persisted. Even babies born at 40 weeks of gestation and birth weight of 3,500-3,999 g (where mortality was lowest) had a 25-fold higher mortality with abruption. The link between fetal growth restriction and abruption suggests that the origins of abruption lie at least in midpregnancy and perhaps even earlier.     

Antecedents of macrosomia

Summary. Antecedents of high birthweight (macrosomia) were studied using the state birth certificates of White singleton infants born in three large metropolitan counties of Washington State from 1984 to 1986. Cases consisted of 2082 live-born macrosomic infants, defined by a birthweight of over 4.5 kg. A random sample of 4440 live births with birthweights of 2.5-4.0kg was selected as a comparison group. Estimates for the independent risks associated with gestational and established diabetes, male sex, parity, duration of gestation, maternal smoking during pregnancy, maternal age, and median income of maternal residential area were obtained and combined in a single logistic model. Maternal smoking was associated with a decreased risk of macrosomia (OR 0.4, 95% CI 0.3-0.5). Established diabetes (OR 6.4, 95% CI 2.7–15.4), gestational diabetes (OR 3.2, 95% CI 2.1–5.1) and male sex of the infant (OR 2.4, 95% CI 2.2-2.7) were associated with an increased risk. Increasing parity was related to an increasing risk from para one (OR 1.4, 95% 1.2-1.6) to para six and greater (OR 3.3, 95% CI 1.5–7.4). Increasing duration of gestation was associated with an increasing risk from 33–36 weeks (OR 0.8, 95% CI 0.5-1.2) to 43–45 weeks (OR 3.3, 95% CI 2.5-4.2). Maternal age, median income of maternal area of residence, and maternal marital status were not significantly associated with macrosomia.     

Birth characteristics and subsequent risk for breast cancer in very young women

There is growing evidence that prenatal exposures may influence later breast cancer risk. This matched case-control study used linked New York State birth and tumor registry data to examine the association between birth characteristics and breast cancer risk among women aged 14-37 years. Cases were women diagnosed with breast cancer between 1978 and 1995 who were also born in New York after 1957 (n = 484). For each case, selected controls were the next six liveborn females with the same maternal county of residence. The authors found a J-shaped association between birth weight and breast cancer risk, and very high birth weight (> or =4,500 g) was associated with the greatest elevation in risk (adjusted odds ratio (OR) = 3.10, 95% confidence interval (CI): 1.18, 7.97). The association of maternal age with breast cancer risk was also J-shaped, with maternal age of more than 24 years showing a positive, linear association (adjusted OR = 1.94, 95% CI: 1.18, 3.18 for maternal age > or =35 vs. 20-24 years; p for trend = 0.02). In contrast, women born very preterm had a lower risk (adjusted OR = 0.11, 95% CI: 0.02, 0.79 for gestational age <33 vs. > or =37 weeks). These findings support a role for early life factors in the development of breast cancer in very young women.     

Antecedents of macrosomia.

Antecedents of high birthweight (macrosomia) were studied using the state birth certificates of White singleton infants born in three large metropolitan counties of Washington State from 1984 to 1986. Cases consisted of 2082 live-born macrosomic infants, defined by a birthweight of over 4.5 kg. A random sample of 4440 live births with birthweights of 2.5-4.0 kg was selected as a comparison group. Estimates for the independent risks associated with gestational and established diabetes, male sex, parity, duration of gestation, maternal smoking during pregnancy, maternal age, and median income of maternal residential area were obtained and combined in a single logistic model. Maternal smoking was associated with a decreased risk of macrosomia (OR 0.4, 95% CI 0.3-0.5). Established diabetes (OR 6.4, 95% CI 2.7-15.4), gestational diabetes (OR 3.2, 95% CI 2.1-5.1) and male sex of the infant (OR 2.4, 95% CI 2.2-2.7) were associated with an increased risk. Increasing parity was related to an increasing risk from para one (OR 1.4, 95% 1.2-1.6) to para six and greater (OR 3.3, 95% CI 1.5-7.4). Increasing duration of gestation was associated with an increasing risk from 33-36 weeks (OR 0.8, 95% CI 0.5-1.2) to 43-45 weeks (OR 3.3, 95% CI 2.5-4.2). Maternal age, median income of maternal area of residence, and maternal marital status were not significantly associated with macrosomia.     

Influence of smoking and snuff cessation on risk of preterm birth

The mechanisms by which antenatal smoking exposure increases the risk of preterm birth remain unknown. Swedish oral moist snuff contains quantities of nicotine comparable to those typically absorbed from cigarette smoking, but does not result in exposure to the products of combustion, for example carbon monoxide. In a nation-wide study of 776,836 live singleton births in Sweden from 1999 to 2009, the authors used multiple logistic regression models to examine associations between cessation of smoking and Swedish snuff use early in pregnancy and risk of preterm birth (before 37 weeks). Compared with non-tobacco users both before and in early pregnancy, the adjusted odds ratios (OR), 95% confidence interval (CI) were OR=0.92, 95% CI 0.84-1.01, for women who stopped using snuff, and OR=0.90, 95% CI 0.87-0.94, for women who stopped smoking. In contrast, continued snuff use and smoking were associated with increased risks of preterm birth (adjusted OR=1.29, 95% CI 1.17-1.43, adjusted OR=1.30, 95% CI 1.25-1.36, respectively). The snuff and smoking-related risks were, if anything, higher for very (before 32 weeks) than moderately (32-36 weeks) preterm birth, and also higher for spontaneous than induced preterm birth. These findings suggest that antenatal exposure to nicotine is involved in the mechanism by which tobacco use increase the risk of preterm birth.     

Extreme prematurity and school outcomes

The purpose of this study was to assess the impact of extreme prematurity on three global measures of school outcomes. Using a matched cohort design, exposed infants comprised all surviving singleton infants < or = 28 weeks gestation born at one regional neonatal intensive care hospital between 1983 and 1986 (n = 132). Unexposed infants comprised randomly selected full-term infants (> or = 37 weeks gestation) frequency matched on date of birth, zip code and health insurance. All children were selected from a regional tertiary children's centre serving western New York population. Standardised telephone interviews elicited information on grade repetition, special education placement and use of school-based services. Unconditional logistic regression was used to estimate odds ratios (OR) and corresponding 95% confidence intervals (CI) adjusted for potential confounders for children without major handicaps. Extreme prematurity was associated with a significant increase in risk of grade repetition (OR = 3.22; 95% CI = 1.63, 6.34), special education placement (OR = 3.16; 95% CI = 1.14, 8.76) and use of school-based services (OR = 4.56; 95% CI = 1.82, 11.42) in comparison with children born at term, even after controlling for age, race, maternal education, foster care placement and the matching factors. These findings suggest that survivors of extreme prematurity remain at risk of educational underachievement.     

Birth rates and reproductive risk in adolescents in Chile, 1990-1999]

OBJECTIVE: For Chilean teenage mothers under 15 years old and from 15 to 19 years old, to evaluate the trends in birth rates and reproductive risk for the period of 1990-1999. METHODS: A database was constructed using data from the Demography Yearbook (Anuario de demografía) volumes published by Chile's National Institute of Statistics (Instituto Nacional de Estadísticas) for 1990-1999. From that database we calculated the trends in the number of live births and in the rates of maternal mortality, late fetal mortality, neonatal mortality, and infant mortality among the teenage mothers under 15 and from 15 to 19 years old. We calculated the risk odds ratio (OR) for both of those age groups in comparison with women from 20 to 34 years old. The groups were compared using Fisher's exact test or the chi-square test, and the analysis of trends in the period studied was carried out with Pearson's correlation, with an alpha level of 0.05. RESULTS: In the period studied, for the teenage mothers under age 15, the respective rates for maternal mortality, late fetal mortality, neonatal mortality, and infant mortality were 41.9 per 100 000 live births, 5.1 per 1 000 live births, 15.2 per 1 000 live births, and 27.4 per 1 000 live births. For the adolescents from 15 to 19 years, the corresponding rates were 19.3, 4.1, 8.1, and 16.6; for the women 20-34 years old, they were 26.8, 5.0, 6.7, and 12.1. The adolescents under 15 had higher risks of maternal mortality (OR = 1.56; 95% confidence interval (CI): 0.50 to 4.31; P = 0.372) and of fetal mortality (OR = 1.02; 95% CI: 0.76 to 1.36; P = 0.890), but those differences were not statistically significant. However, the younger adolescents did have significantly higher risks of neonatal mortality (OR = 2.27; 95% CI: 1.92-2.68; P < 0.0001) and of infant mortality (OR = 2.39; 95% CI: 2.04 to 2.62; P < 0.0001). In comparison to the women 20-34 years old, the teenage mothers from 15 to 19 years old had significantly lower risks of maternal mortality (OR = 0.72; 95% CI: 0.56 to 0.92; P < 0.008) and of fetal mortality (OR = 0.81; 95% CI: 0.77 to 0.86; P < 0.0001) but significantly higher risks of neonatal mortality (OR = 1.20; 95% CI: 1.16 to 1.25; P < 0.0001) and of infant mortality (OR = 1.38; 95% CI: 1.35 to 1.42; P < 0.0001). Among both the older teenage mothers and the mothers 20-34 years old there was a significant downward trend in maternal, fetal, neonatal, and infant mortality rates in the period studied; in the younger adolescents only neonatal mortality and infant mortality declined significantly. There was a rising trend in the number of live births among the two groups of teenage mothers, but that trend was statistically significant only for the mothers under 15; among mothers 20-34 years old there was a statistically significant downward trend. CONCLUSIONS: In the period studied, the Chilean teenage mothers faced greater reproductive risk than did the women 20-34 years old. The number of live births among teenage mothers tended to rise during the 1990-1999 period, but the change was significant only for the mothers under age 15. These results point to the need to develop programs that improve both sex education and birth control practices starting in early adolescence.     

Mothers' and fathers' birth characteristics and perinatal mortality in their offspring: a population‐based cohort study

Nordtveit TI, Melve KK, Skjaerven R. Mothers' and fathers' birth characteristics and perinatal mortality in their offspring: a population‐based cohort study. Paediatric and Perinatal Epidemiology 2010; 24: 282–292. There is increasing interest in the associations between parental birthweight and gestational age with their perinatal outcomes. We investigated perinatal mortality risk in offspring in relation to maternal and paternal gestational age and birthweight. We used population‐based generational data from the Medical Birth Registry of Norway, 1967–2006. Singletons in both generations were included, forming 520 794 mother–offspring and 376 924 father–offspring units. Perinatal mortality in offspring was not significantly associated with paternal gestational age or birthweight, whereas it was inversely associated with maternal gestational age. A threefold increased risk in perinatal mortality was found among offspring of mothers born at 28–30 weeks of gestation relative to offspring of mothers born at term (37–43 weeks) (relative risk: 2.9, 95% CI 1.9, 4.6). There was also an overall association between maternal birthweight and offspring perinatal mortality. Relative risk for mothers whose birthweight was <2000 g was 1.5 (95% CI 1.1, 1.9), relative to mothers whose birthweight was 3500–3999 g. However, confined to mothers born at ≥34 weeks of gestation, the birthweight association was not significant. Weight‐specific perinatal mortality in offspring was dependent on the birthweight of the mother and the father, that is, offspring who were small relative to their mother's or father's birthweight had increased perinatal mortality. In conclusion, a mother's gestational age, and not her birthweight, was significantly associated with perinatal mortality in the offspring, while there was no such association for the father.     

Maternal occupation and adverse pregnancy outcomes: a Finnish population-based study

BACKGROUND: There is accumulating evidence that the type of work and environmental exposures in the working environment may have adverse effects on foetal development. AIM: To compare the risk of low birth weight (LBW), small-for-gestational age (SGA) and pre-term delivery (PD) in broad categories of maternal occupation including farming and forestry; factory, mining and construction; office, non-manual and service work and housewives. METHODS: The study population consisted of 2568 singleton newborns of women who participated in The Finnish Prenatal Environment and Health Study after the delivery (response rate 94%). Information on maternal occupation and work during pregnancy was collected after the delivery. The health outcomes were LBW (<2500 g), SGA and PD (<37 weeks). RESULTS: In newborns of women working in factories, mining and construction, the risk of LBW (adjusted odds ratio [OR] 3.66, 95% confidence interval [CI] 1.15-11.62), SGA (adjusted OR 1.53, 95% CI 0.73-3.21), but not the risk of PD (adjusted OR 0.64, 95% CI 0.19-2.22), was higher compared with newborns of housewives. In newborns of farmers and forestry workers, the risks of PD (adjusted OR 2.38, 95% CI 1.01-5.65), LBW (adjusted OR 2.86, 95% CI 0.78-11.58) and SGA (adjusted OR 1.51, 95% CI 0.62-3.65) were all elevated. In office, non-manual and service workers, the corresponding estimates were lower (LBW: 1.62, 0.67-3.95; SGA: 1.45, 0.92-2.28; PD: 1.18, 0.69-2.01). CONCLUSIONS: There were substantial differences in the risk of adverse pregnancy outcomes between the main branches of industry.     

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.     

Partner violence during pregnancy and risk of adverse pregnancy outcomes

The purpose of this cross-sectional study was to investigate the association between partner physical or emotional abuse during pregnancy and pregnancy outcomes including perinatal death, low birthweight and preterm delivery. Women, aged 18-65, who attended one of two large primary care practices from 1997-98 were recruited for this study. Ever pregnant women were asked the frequency of abuse during each pregnancy and details of the pregnancy outcomes. Information regarding abuse during pregnancy and pregnancy outcomes was available for 755 women surveyed who reported a live birth or late fetal death, 14.7% indicated that an intimate partner was violent or abusive toward them during a pregnancy (274 of 1862 pregnancies). Abuse during pregnancy was significantly associated with an increased risk of perinatal death (adjusted relative risk [aRR] = 2.1, 95% confidence interval [CI] 1.3, 3.4) and, among live births, with preterm low birthweight (aRR = 2.4; 95% CI 1.5, 4.0) and term low birthweight (aRR = 1.9; 95% CI 1.0, 3.4). Greater abuse frequency was associated with increased risk. Abuse during pregnancy was associated with perinatal deaths and preterm low birthweight deliveries.     

Risk factors for early infant mortality in Sarlahi district, Nepal

OBJECTIVES: Early infant mortality has not declined as rapidly as child mortality in many countries. Identification of risk factors for early infant mortality may help inform the design of intervention strategies. METHODS: Over the period 1994-97, 15,469 live-born, singleton infants in rural Nepal were followed to 24 weeks of age to identify risk factors for mortality within 0-7 days, 8-28 days, and 4-24 weeks after the birth. FINDINGS: In multivariate models, maternal and paternal education reduced mortality between 4 and 24 weeks only: odds ratios (OR) 0.28 (95% confidence interval (CI) = 0.12-0.66) and 0.63 (95% CI = 0.44-0.88), respectively. Miscarriage in the previous pregnancy predicted mortality in the first week of life (OR = 1.98, 95% CI = 1.37-2.87), whereas prior child deaths increased the risk of post-neonatal death (OR = 1.85, 95% CI 1.24-2.75). A larger maternal mid-upper arm circumference reduced the risk of infant death during the first week of life (OR = 0.88, 95% CI = 0.81-0.95). Infants of women who did not receive any tetanus vaccinations during pregnancy or who had severe illness during the third trimester were more likely to die in the neonatal period. Maternal mortality was strongly associated with infant mortality (OR = 6.43, 95% CI = 2.35-17.56 at 0-7 days; OR = 11.73, 95% CI = 3.82-36.00 at 8-28 days; and OR = 51.68, 95% CI = 20.26-131.80 at 4-24 weeks). CONCLUSION: Risk factors for early infant mortality varied with the age of the infant. Factors amenable to intervention included efforts aimed at maternal morbidity and mortality and increased arm circumference during pregnancy.     

Risk factors for neonatal and post-neonatal mortality in the Central-West region of Brazil: linkage between live birth and infant death data banks

This article focused on risk factors for neonatal and post-neonatal mortality by linking live births and infant death records. The study was conducted in the municipality of Goiania, in the Central-West region of Brazil. A total of 20,981 live births and 342 infant deaths constitute the retrospective cohort. Neonatal and post-neonatal mortality risks were estimated in this cohort study of live births by logistic regression. In the neonatal period, the highest ORs were for delivery in public hospitals (OR = 2.28; 95% CI 1.57-3.32), pre-term neonates (OR = 8.94; 95% CI 5.85-13.67), and low birth weight (OR = 8.92; 95% CI 5.77-13.79). Cesarean delivery appeared as a protective factor (OR = 0.58; 95% CI 0.43-0.78). For post-neonatal mortality, the highest ORs were for illiterate mothers (OR = 6.25; 95% CI 1.25-31.27), low birth weight (OR = 3.12; 95% CI 1.67-5.84), and delivery in public hospitals (OR = 2.65; 95% CI 1. 13-6.23). The linkage identified socioeconomic variables that were more important risk factors for post-neonatal than neonatal mortality.     

Childhood brain tumor risk in relation to birth characteristics

A population-based case-control study was conducted utilizing linked cancer registry and birth certificate data to examine potential associations between selected birth characteristics and the occurrence of brain tumors in children. Cases (n = 157) were those children ages 10 and under who were born in Washington state and who were diagnosed with a primary brain tumor between 1974 and 1986. Controls were randomly selected from the Washington State birth files and were matched 5:1 to cases on year and county of birth. A limited number of positive findings emerged from the study. Results suggested that high birthweight may be related to an increased risk of childhood brain tumor (odds ratio (OR) = 1.4, 95% CI 1.0-2.0 for all histologies combined; OR = 1.9, 95% CI 1.1-3.1 for astrocytomas). The risk of astrocytoma was also observed to be associated with older maternal age (OR = 2.2, 95% CI 1.2-4.0) and a history of prior fetal death(s) (OR = 1.9, 95% CI 1.0-3.8).