Undiagnosed coeliac disease in a father does not influence birthweight and preterm birth

Khashan AS, Kenny LC, McNamee R, Mortensen PB, Pedersen MG, McCarthy FP, Henriksen TB. Undiagnosed coeliac disease in a father does not influence birthweight and preterm birth. Paediatric and Perinatal Epidemiology 2010. There is conflicting evidence regarding the effect of coeliac disease (CD) in the father on birthweight and preterm birth. We investigated the association between paternal CD and birthweight and preterm birth. Medical records of all singleton live‐born children in Denmark between 1 January 1979 and 31 December 2004 were linked to information about parents' diseases. Fathers who were diagnosed with CD were then identified. Fathers with CD were considered treated if they were diagnosed before pregnancy and untreated if they were diagnosed after the date of conception. The outcome measures were: birthweight, small‐for‐gestational age (birthweight<10th centile for gestational age) and preterm birth (<37 weeks). We compared the offspring of men without CD (n = 1 472 352) and offspring of those with CD [untreated (n = 138) and treated (n = 473)]. There was no significant association between untreated CD in the father and birthweight (adjusted mean difference = ?3 g; [95% CI ?46, 40]) or preterm birth (adjusted odds ratio (OR) = 0.86, [95% CI 0.53, 1.37]) (compared with no CD). There was some evidence for an association between treated paternal CD and birthweight (adjusted mean difference = ?81 g; [95% CI ?161, ?3]), but not preterm birth (adjusted OR = 1.76, [95% CI 0.95, 3.26]). Untreated paternal CD was not associated with an increased risk of reduced birthweight, or of preterm birth. There was some evidence that diagnosis and presumed treatment of paternal CD with a gluten‐free diet is associated with reduced birthweight.     

Is conception delay a risk factor for reduced gestation or birthweight?

Previous studies have suggested an association between delays in conception and adverse perinatal outcomes, specifically, low birthweight and preterm birth. We investigated the relationship between conception delay (defined as >6 months to become pregnant) and three perinatal outcomes: low birthweight (LBW; <2500 g), preterm birth (PTB; <37 weeks), and small-for-gestational-age (SGA; <10th percentile weight for given gestational age) using data from the Collaborative Perinatal Project. The study cohort was limited to pregnancies with a known time-to-pregnancy (n = 8465; 15%). Generalised estimating equations were used to estimate odds ratios (OR) and 95% confidence intervals [CI] for risk of adverse perinatal outcomes accounting for the clustering of pregnancy outcomes for women with more than one pregnancy. After adjusting for confounders, all ORs were close to the null (LBW, OR = 1.01; 95% CI = 0.86, 1.20), (PTB, OR = 1.10; 95% CI = 0.95, 1.27), (SGA, OR = 1.06; 95% CI = 0.91, 1.25). Thus, we found no evidence to support an adverse relationship between conception delay and decrements in gestation or birthweight among this select sample of fertile women, even after varying the cut-point for defining conception delay.     

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.     

Disparities in the prevalence of cognitive delay: how early do they appear?

Cognitively delayed children are at risk for poor mental and physical health throughout their lives. The economically disadvantaged and some race/ethnic groups are more likely to experience cognitive delay, but the age at which delays first emerge and the underlying mechanisms responsible for disparities are not well understood. The objective of this study was to determine when sociodemographic disparities in cognitive functioning emerge, and identify predictors of low cognitive functioning in early childhood. Data were from 7308 singleton and 1463 multiple births in the Early Childhood Longitudinal Study‐Birth Cohort (ECLS‐B), a nationally representative cohort of children born in the USA in 2001. Multiple logistic regression analyses examined associations between sociodemographic characteristics and low cognitive functioning at 9 and 24 months, and tested whether gestational and birth‐related factors mediate these associations. Sociodemographic characteristics were statistically significant predictors of low cognitive functioning among singletons at 24 months, including the three lowest quintiles of socio‐economic status [lowest quintile, odds ratio (OR) = 2.7, 95% confidence interval [CI][1.7, 4.1]], non‐white race/ethnicity (African American OR = 1.8 [95% CI 1.3, 2.5], Hispanic OR = 2.3 [95% CI 1.6, 3.2]), and gender (male OR = 2.1, [95% CI 1.7, 2.5]). Gestational and birth characteristics associated with low cognitive function at 9 months included very low and moderately low birthweight (OR = 55.0 [95% CI 28.3, 107.9] and OR = 3.6 [95% CI 2.6, 5.1]), respectively, and very preterm and moderately preterm delivery (OR = 3.6 [95% CI 2.0, 6.7] and OR = 2.4 [95% CI 1.7, 3.5]), respectively, but they had weaker effects by 24 months (ORs for birthweight: 3.7 [95% CI 2.3, 5.9] and 1.8 [95% CI 1.4, 2.3]; ORs for preterm: 1.8 [95% CI 1.1, 2.9] and 0.9 [95% CI 0.7, 1.3]). Results for multiple births were similar. Sociodemographic disparities in poor cognitive functioning emerged by 24 months of age, but were not mediated by gestational or birth characteristics. Further investigation of processes whereby social disadvantage adversely affects development prior to 24 months is needed.     

Determinants of developmental delay in infants aged 12 months

The aim of this study was to determine which demographic, maternal, obstetric and postnatal variables were associated with achievement of developmental milestones at the age of 12 months in term infants. Mothers and babies were enrolled in the Auckland Birthweight Collaborative Study shortly after birth. All infants were full term (gestation >or= 37 weeks). Approximately half of the sample were small for gestational age (SGA = birthweight 10th percentile). A maternal interview was conducted soon after birth. Phase 2 of the study occurred 12 months later when mothers were sent a postal questionnaire requesting information about the child's health and development during the first year of life using the Denver Prescreening Developmental Questionnaire. Seven hundred and forty-four (85.4%) European mothers returned the postal questionnaire. SGA children were not at increased risk of developmental delay at 12 months of age. In a sample representative of New Zealand European children, after adjustment for the effects of potential confounders, maternal smoking during pregnancy (OR = 2.1 [95% CI 1.1, 4.0]), maternal smoking during the first year of life (OR = 1.9 [95% CI 1.0, 3.8]) and low levels of satisfaction with parenting (OR = 2.4 [95% CI 1.1, 5.2]) were associated with significantly increased risk of developmental delay. In the subgroup of SGA children, maternal smoking during pregnancy (OR = 2.9 [95% CI 1.4, 6.2]), high levels of stress associated with parenting (OR = 2.2 [95% CI 1.2, 4.0]), and low levels of satisfaction with parenting (OR = 4.3 [95% CI 1.3, 13.5]) were significantly associated with developmental delay after adjustment for the effects of potential confounders. In conclusion, maternal and postnatal factors were better predictors of developmental delay than demographic variables.     

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).     

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。     

Challenge of reducing perinatal mortality in rural Congo: findings of a prospective, population-based study

Each year, an estimated six million perinatal deaths occur worldwide, and 98% of these deaths occur in low- and middle-income countries. These estimates are based on surveys in both urban and rural areas, and they may underrepresent the problem in rural areas. This study was conducted to quantify perinatal mortality, to identify the associated risk factors, and to determine the most common causes of early neonatal death in a rural area of the Democratic Republic of the Congo (DRC). Data were collected on 1,892 births. Risk factors associated with perinatal deaths were identified using multivariate analysis with logistic regression models. Causes of early neonatal deaths were determined by physician-review of information describing death. The perinatal mortality rate was 61 per 1,000 births; the stillbirth rate was 30 per 1,000 births; and the early neonatal death rate was 32 per 1,000 livebirths. Clinically-relevant factors independently associated with perinatal death included: low birthweight [odds ratio (OR)=13.51, 95% confidence interval (CI) 7.82-23.35], breech presentation (OR)=12.41; 95% CI 4.62-33.33), lack of prenatal care (OR=2.70, 95% CI 1.81-4.02), and parity greater than 4 (OR=1.93 95% CI 1.11-3.37). Over one-half of early neonatal deaths (n=37) occurred during the first two postnatal days, and the most common causes were low birthweight/prematurity (47%), asphyxia (34%), and infection (8%). The high perinatal mortality rate in rural communities in the DRC, approximately one-half of which is attributable to early neonatal death, may be modifiable. Specifically, deaths due to breech presentation, the second most common risk factor, may be reduced by making available emergency obstetric care. Most neonatal deaths occur soon after birth, and nearly three-quarters are caused by low birthweight/prematurity or asphyxia. Neonatal mortality might be reduced by targeting interventions to improve neonatal resuscitation and care of larger preterm infants.     

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.     

Pregnancy outcome among offspring of airline pilots and cabin attendants

OBJECTIVES: This study assessed the occurrence of perinatal death, low birthweight, preterm birth, and birth defects (total, major, neural tube defects, total cleft, cleft palate, hypospadias, and Down syndrome) in the offspring of airline pilots and cabin attendants. METHODS: A cohort of offspring of airline pilots and cabin attendants was established and characterized in terms of parental exposure to cosmic radiation the year before birth or ever. Pregnancy outcome was derived from the Medical Birth Register of Norway. The reference group comprised offspring of parents without occupational exposure to cosmic radiation. RESULTS: No deviant risks were observed for the offspring of male pilots, either for the year preceding birth (N=2,111) or ever (N=2,356). Specific birth outcomes were fewer for the pilots than for the referents (N=1,621,186), except for Down syndrome, which was more frequent [odds ratio (OR) 1.41, 95% confidence interval (95% CI) 0.53-3.76]. For exposure the year preceding birth (N=2,512), the risk of low birthweight was lower for the female cabin attendants than for the referents (adjusted OR 0.83, 95% CI 0.69-1.00), while Down syndrome was more frequent (OR 1.44, 95% CI 0.60-3.47). For exposure ever (N=3346), the risk of low birthweight was lower (OR 0.82, 95% CI 0.70-0.96) for the cabin attendants, while hypospadias (OR 1.18, 95% CI 0.61-3.04) and Down syndrome (OR 1.79, 95% CI 0.03-3.45) were more frequent CONCLUSIONS: In general, offspring of air pilots and cabin attendants do not seem to be at increased risk of adverse pregnancy outcome.     

Population‐Based Study of Risk Factors for Severe Maternal Morbidity

Background: Severe maternal morbidity (SMM) is a serious health condition potentially resulting in death without immediate medical attention, including organ failure, obstetric shock and eclampsia. SMM affects 20 000 US women every year; however, few population‐based studies have examined SMM risk factors. Methods: We conducted a population‐based case–control study linking birth certificate and hospital discharge data from Washington State (1987–2008), identifying 9485 women with an antepartum, intrapartum or postpartum SMM with ≥3‐day hospitalisation or transfer from another facility and 41 112 random controls. Maternal age, race, smoking during pregnancy, parity, pre‐existing medical condition, multiple birth, prior caesarean delivery, and body mass index were assessed as risk factors with logistic regression to estimate odds ratios (OR) and 95% confidence intervals [CI], adjusted for education and delivery payer source. Results: Older women (35–39: OR 1.65 [CI 1.52, 1.79]; 40+: OR 2.48 [CI 2.16, 2.81]), non‐White women (Black: OR 1.82 [CI 1.64, 2.01]; American Indian: OR 1.52 [CI 1.32, 1.73]; Asian/Pacific Islander: OR 1.30 [CI 1.19, 1.41]; Hispanic: OR 1.17 [CI 1.07, 1.27]) and women at parity extremes (nulliparous: OR 1.83 [CI 1.72, 1.95]; parity 3+: OR 1.34 [CI 1.23, 1.45]) were at greater risk of SMM. Women with a pre‐existing medical condition (OR 2.10 [CI 1.88, 2.33]), a multiple birth (OR 2.54 [CI 2.26, 2.82]) and a prior caesarean delivery (OR 2.08 [CI 1.93, 2.23]) were also at increased risk. Conclusion: The risk factors identified are not modifiable at the individual level; therefore, provider and system‐level factors may be the most appropriate target for preventing SMM.     

Adverse perinatal and neonatal outcomes and their determinants in rural Vietnam 1999-2005

Population-based estimations of perinatal and neonatal outcomes are sparse in Vietnam. There are no previously published data on small for gestational age (SGA) infants. A rural population in northern Vietnam was investigated from 1999 to 2005 (n=5521). Based on the birthweight distributions within the population under study, reference curves for intrauterine growth for Vietnamese infants were constructed and the prevalence and distribution of SGA was calculated for each sex. Neonatal mortality was estimated as 11.6 per 1000 live births and the perinatal mortality as 25.0 per 1000 births during the study period. The mean birthweight was 3112 g and the prevalence of low birthweight was 5.0%. The overall prevalence of SGA was 6.4%. SGA increased with gestational age and was 2.2%, 4.5% and 27.1% for preterm, term and post-term infants, respectively. Risk factors for SGA were post-term birth: adjusted odds ratio (AOR) 7.75 [95% CI 6.02, 9.98], mothers in farming occupations AOR 1.72 [95% CI 1.21, 2.45] and female infant AOR 1.61 [95% CI 1.27, 2.03]. There was a pronounced decrease in neonatal mortality after 33 weeks of gestation. Suggested interventions are improved prenatal identification of SGA infants by ultrasound investigation for fetal growth among infants who do not follow their expected clinical growth curve at the antenatal clinic. Other suggestions include allocating a higher proportion of preterm deliveries to health facilities with surgical capacity and neonatal care.     

Maternal age and preterm births in a black population

Babies born to teenagers aged 15-19 years have a substantial risk of dying within the first year of life. Although associated socio-demographic factors may account for an increase in the risk of adverse reproductive outcomes for teenagers, there is a concern that young maternal age may also be a biological risk factor. We examined the effects of maternal age of primiparous black women on the incidence of preterm births using data from 6,072 black women delivering between 1989 and 1995 at an urban perinatal network of 17 hospitals and health centres serving residents in a well-defined geographical area. Maternal age was grouped as: < or = 15, 16-17, 18-19, 20-24, 25-29 or > or = 30 years age groups. The 20-24 age group with the highest number of births and lowest preterm rate was used as the reference age. Preterm birth was defined as delivery < 37 completed weeks of gestation. Of the 6,072 infants born to the cohort, 1,170 (19.3%) were preterm. The unadjusted odds for a preterm birth for the < or = 15-year-olds (odds ratio [OR] = 0.97; 95% confidence interval [CI], 0.69,1.36), for the 16- to 17-year-olds (OR=1.21; CI=0.94, 1.57) and for the 18- to 19-year olds (OR=1.15, CI = 0.92, 1.43) were not significantly different from that for the reference group. The risk for the 25-to 29-year-old mothers was 1.26 times [CI = 1.05, 1.50] and for the > 30-year-old mothers 1.28 times [CI = 1.07, 1.52] that for the reference group. Adjustments using logistic regression analysis for the effects of maternal smoking, drug abuse during pregnancy, insurance status, having prenatal care and median family income from census tract of residence did not result in a significantly increased risk for preterm birth or low birthweight for the teenage groups compared with the reference group. We conclude that primiparous teenage black mothers do not have an inherent biologically increased risk for preterm births.     

Prospective community-based cluster census and case-control study of stillbirths and neonatal deaths in the West Bank and Gaza Strip

Obstetric complications and newborn illnesses amenable to basic medical interventions underlie most perinatal deaths. Yet, despite good access to maternal and newborn care in many transitional countries, perinatal mortality is often not monitored in these settings. The present study identified risk factors for perinatal death and the level and causes of stillbirths and neonatal deaths in the West Bank and Gaza Strip. Baseline and follow-up censuses with prospective monitoring of pregnant women and newborns from September 2001 to August 2002 were conducted in 83 randomly selected clusters of 300 households each. A total of 113 of 116 married women 15-49 years old with a stillbirth or neonatal death and 813 randomly selected women with a surviving neonate were interviewed, and obstetric and newborn care records of women with a stillbirth or neonatal death were abstracted. The perinatal and neonatal mortality rates, respectively, were 21.2 [95% confidence interval (CI) 16.5, 25.9] and 14.7 [95% CI 10.2, 19.2] per 1000 livebirths. The most common cause (27%) of 96 perinatal deaths was asphyxia alone (21) or with neonatal sepsis (5), while 18/49 (37%) early and 9/19 (47%) late neonatal deaths were from respiratory distress syndrome (12) or sepsis (9) alone or together (6). Constraint in care seeking, mainly by an Israeli checkpoint, occurred in 8% and 10%, respectively, of 112 pregnancies and labours and 31% of 16 neonates prior to perinatal or late neonatal death. Poor quality care for a complication associated with the death was identified among 40% and 20%, respectively, of 112 pregnancies and labour/deliveries and 43% of 68 neonates. (Correction added after online publication 5 June 2008: The denominators 112 pregnancies, labours, and labour/deliveries, and 16 and 68 neonates were included; and 9% of labours was corrected to 10%.) Risk factors for perinatal death as assessed by multivariable logistic regression included preterm delivery (odds ratio [OR] = 11.9, [95% CI 6.7, 21.2]), antepartum haemorrhage (OR = 5.6, [95% CI 1.5, 20.9]), any severe pregnancy complication (OR = 3.4, [95% CI 1.8, 6.6]), term delivery in a government hospital and having a labour and delivery complication (OR = 3.8, [95% CI 1.2, 12.0]), more than one delivery complication (OR = 4.4, [95% CI 1.8, 10.5]), mother's age >35 years (OR = 2.9, [95% CI 1.3, 6.8]) and primiparity in a full-term pregnancy (OR = 2.6, [1.1, 6.3]). Stillbirths are not officially reportable in the West Bank and Gaza Strip and this is the first time that perinatal mortality has been examined. Interventions to lower stillbirths and neonatal deaths should focus on improving the quality of medical care for important obstetric complications and newborn illnesses. Other transitional countries can draw lessons for their health care systems from these findings.     

Pregnancy Intendedness,Maternal Psychosocial Factors and Preterm Birth

Objectives: This study examined associations between reported pregnancy intendedness and several maternal psychosocial factors in relation to preterm birth (<37 weeks' completed gestation). Methods: Women were recruited into a prospective cohort study between the 24th and 29th weeks of pregnancy in central North Carolina from 1996 to 2000. Prior to delivery, participants responded to questions about pregnancy intendedness, life events impacts, depressive symptoms, and coping style. Results: Women who reported not intending their pregnancy had increased odds of reporting low, medium and high levels of perceived stress during pregnancy (OR = 1.4 [95% CI: 1.1, 1.9], OR = 2.2 [95% CI: 1.7, 2.8], and OR = 3.4 [95% CI: 2.6, 4.5], respectively, relative to very low), medium and high levels of depressive symptoms (OR = 2.2 [95% CI: 1.8, 2.9] and OR = 3.1 [95% CI: 2.4, 3.9], respectively), and medium and high levels of several coping styles. Reporting not intending the pregnancy was not associated with increased risk of preterm birth (Risk Ratio [RR] = 1.0, 95% CI: 0.8, 1.1), but reporting the highest quartile of perceived stress (RR = 1.6, 95% CI: 1.1, 2.3) and the highest tertile of distancing coping style (compared with lowest quartile) was associated with preterm birth (RR = 1.4, 95% CI: 1.1, 1.9). Interactions between pregnancy intendedness and the psychosocial variables perceived stress, depression or coping style did not modify the psychosocial variable's associations with preterm birth. Conclusions: Pregnancy intendedness remains an important concept in the reproductive health literature integrally tied to indicators of maternal mental health, but not necessarily to pregnancy outcomes.     

The influence of maternal age on very preterm birth of twins: differential effects by parity

For singleton births, parity can modify the effect of maternal age on birth outcomes such as low birthweight and preterm birth; however, it is unknown whether this relationship exists for twin births. As the rate of twin births increases among older women, it is important to understand how parity may influence the relationship between maternal age and adverse birth outcomes. The NCHS Matched Multiple Birth Data Set, which contains all twin births in the USA from 1995 to 1998, was analysed. Parity was grouped into two levels (primiparous--no prior live births, and multiparous--at least one prior live birth), and maternal age was divided into the following groups: 20-24, 25-29, 30-34, 35-39, and 40 years or more. Very preterm birth was defined as births occurring before 33 weeks. Logistic regression was used to obtain odds ratios (OR) to estimate the risk of very preterm birth, and to determine the relationships between parity, maternal age, and very preterm birth. Among primiparae, women 40 years and older had a reduced risk of very preterm birth compared with women of 25-29 years (OR 0.74 [95% CI=0.66, 0.84]). Among multiparae, women 40 years and older had the same risk of very preterm birth compared with women of 25-29 years (OR 1.00 [95% CI=0.90, 1.12]). However, stratification by education revealed that the age gradient was limited to women with >12 years education among primiparae. The effect of maternal age on very preterm birth of twins differs according to parity. To some extent, that effect is further modified by education. Therefore, future analyses of maternal age and twin birth outcomes should account for measures of obstetric history and other factors, which may influence these results.     

Risks of repeated miscarriage

There is a lack of well-designed epidemiological studies of possible risk factors for repeated miscarriage. In this Swedish population-based case-control study, we investigated the association between sociodemographic and anthropometric factors, obstetric history and life-style factors, with respect to the risks of first-trimester repeated miscarriage. Information on maternal characteristics was collected through in-person interviews. Plasma blood samples were analysed for cotinine and folate concentrations. Adjusted odds ratios (OR) with 95% confidence interval [CI] were used to estimate the relative risk of repeated miscarriage. The risks of repeated miscarriage were increased for women aged > or = 35 years (adjusted OR 2.9 [95% CI 1.4, 5.8]), as well as for women aged < or = 24 years (OR 2.8 [95% CI 1.1, 6.8]). Women with a history of at least one preceding miscarriage prior to the two index pregnancies, women reporting prolonged time to conceive, and women with a history of myoma, faced a more than fourfold increased risk of repeated miscarriage. Smokers were at an increased risk of repeated miscarriage (OR 2.1 [95% CI 1.1, 4.1]). Among non-smoking women with high caffeine intake, there was an increased risk of repeated miscarriage, whereas there was no such association among smokers. Low plasma folate levels were not associated with increased risks.     

Effect of smoking and alcohol use during pregnancy on the occurrence of low birthweight in a farming region in South Africa

The aim of this case-control study was to determine the risk factors for low birthweight in a farming region in South Africa, with particular attention to maternal alcohol use and smoking, both independently and in combination. Data collection was via structured postpartum interviews and review of antenatal and delivery records. The study setting was a regional referral hospital in a farming region. The study subjects were 200 infants with birthweight < 2500 g (cases) and 200 unmatched control infants of normal weight born during the same period as the cases. The outcome measure was low birthweight, i.e. infant birthweight <2500 g. Results showed the contribution of term low birthweight (as a measure of intrauterine growth retardation) to the total low-birthweight incidence was almost 50%, indicating a substantial intrauterine growth retardation component in this population. Sociodemographic factors were not as predictive of low birthweight in this predominantly low income population. Smoking (adjusted OR 2.67, [95% CI 1.69, 4.20]) was the strongest life style-related predictor of low birthweight. The alcohol low-birthweight relationship was not significant when adjusted for smoking status (crude OR 2.15, [95% CI 1.37, 3.39]; adjusted OR 1.32, [95% CI 0.80, 2.20]). However, there appeared to be an interaction with combined use of these two substances during pregnancy that increased the risk of low birthweight (adjusted OR increased to 4.24, [95% CI 1.01, 17.76]. It is clear that life style factors such as smoking and drinking are contributing to the occurrence of low birthweight in the target region. A comprehensive health promotion programme needs to be implemented as an integral part of antenatal and family planning services, to reduce smoking and drinking by women in this community.     

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.     

Perinatal mortality associated factors in a general hospital of Chiapas, Mexico

OBJECTIVE: To identify socioeconomic, gynecological-obstetric and fetal factors associated with perinatal mortality. METHODS: A matched case-control study was carried out. Cases were newborns (born live or dead) that were born and died between 28 weeks gestation and 7 days of life. Controls were live newborns between 28 weeks gestation and 7 days of life. A total of 99 cases and 197 controls were studied. Data were obtained from the corresponding medical charts. Statistical analysis was performed using Stata 6.0 software. RESULTS: Mean maternal age was 24.82 years and mean newborn age was 37.78 weeks gestation with an average birth weight of 2,760 grams. Factors associated with perinatal mortality were: father's occupation as a farmer (adjusted odds ratio (OR)=3.31; 95% CI=1.26-8.66); high obstetric risk index (adjusted OR=10.57; 95% CI=2.82-39.66), cesarean birth (adjusted OR=2.75; 95% CI=1.37-5.51), five or more prenatal visits (adjusted OR=4.43; 95% CI=1.86-10.54) and preterm fetal maturity indices (PEG, APG, GEG) (adjusted OR=9.20; 95% CI=4.39-19.25). CONCLUSIONS: The risk factors associated with perinatal mortality found in the study are consistent with the findings reported in the international literature. These results show that prevention and control measures should be implemented to identify at risk pregnant women in order to lower perinatal mortality.