Determinants of Small for Gestational Age Birth at Term

Background: Being born small for gestational age (SGA) is an indicator of intrauterine growth restriction (IUGR) and later health risks. This study investigated determinants of severe and moderate SGA (respectively, birthweight <3rd percentile and 3rd to <10th percentile for gestational age and sex). Methods: A total of 2195 term pregnancies from a prospective cohort were studied. Prenatal data arose from maternal interview at 10–22 weeks of gestation and perinatal data were collected from hospital charts. Severe and moderate SGA were classified by Canadian population standards. Risk factors for SGA were identified from fitting multivariable logistic regression models. Results: Multivariable associations with severe SGA were: maternal age ≥ 35 [odds ratio (OR) 3.2 [95% confidence interval (CI) 1.4, 6.9]], maternal smoking during pregnancy (OR 5.3 [95% CI 2.4, 11.7]), preeclampsia (OR 4.6 [95% CI 1.6, 13.2]) and threatened preterm labour (OR 3.9 [95% CI 1.3, 11.4]). Primiparity was associated with both severe and moderate SGA with OR 2.4 [95% CI 1.1, 5.1] and OR 1.9 [95% CI 1.3, 2.9] respectively. Underweight pre‐pregnancy body mass index was associated with moderate SGA (OR 2.4 [95% CI 1.2, 5.0]). Inclusion of placental weight, in the final model attenuated the associations. Conclusions: This study demonstrated different determinants for severe and moderate SGA. We speculate that the majority of severe SGA infants are IUGR while moderate SGA infants may be a mixture of IUGR and constitutionally small newborns. This study has also contributed evidence linking preterm labour and SGA as two, potentially related, outcomes of overlapping causal mechanisms reflective of ischaemic placental disease.     

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.     

The impact of maternal education on intrauterine growth: a comparison of former West and East Germany

BACKGROUND: Objective of this re-analysis of datasets from former East and West Germany was to examine the influence of maternal education on intrauterine growth in two different political and social systems. METHODS: Information on socio-demographic or lifestyle factors and pregnancy outcome was available for 3374 liveborn singletons from West Germany (1987/88) and 3070 from East Germany (1990/91). Multiple logistic regression was used to estimate the association between maternal education and the risk of delivering a small-for-gestational-age (SGA) newborn below the 10th percentile of birthweight. RESULTS: Women with the lowest education had a significantly elevated risk of SGA newborns compared to women with the highest education in West (odds ratio [OR] = 2.58, 95% CI : 1.17-5.67) and East Germany (OR = 2.77, 95% CI : 1.54- 5.00). The distribution of factors known to influence intrauterine growth varied with education in both states. After adjusting for these factors, women with the lowest educational level still had a higher risk of SGA birth: OR (West) = 2.02, 95% CI : 0.87-4.72; OR (East) = 1.95, 95% CI : 1.02-3.74. CONCLUSIONS: Our findings support the assumption that in former socialist countries health inequalities as a result of social inequalities existed.     

Risk factors for small-for-gestational age births among infants in Brazil

OBJECTIVE: To assess the risk factors for small-for-gestational-age (SGA) births. METHODS: All live births occurring in the city of Pelotas, Brazil, between October and December 1993 were identified and mothers interviewed soon after delivery. Birthweight was recorded by the maternity staff. Gestational age was obtained from the mothers' recall of their date of last menstrual period. SGA was defined as a birthweight below the 10th percentile for gestational age and sex, according to the reference developed by Williams. Chi-square test and logistic regression were used in the crude and multivariate analysis, respectively. RESULTS: In all, 1082 births were identified. The prevalence of SGA was 13.1%. Even after adjusting for possible confounding variables, the odds ratio for SGA among those infants whose family income was <1 minimum wage was 8.81 (95% CI, 1.12-69.46) times higher than among those for infants with a family income > or = minimum wage. An antenatal care of low quality was associated with an odds ratio of 3.28 (95% CI, 1.09-9.91) for SGA. Short maternal stature and maternal smoking during pregnancy were also associated with SGA births. CONCLUSIONS: Low socioeconomic status, maternal smoking during pregnancy, maternal height and an antenatal care of low quality are the main risk factors for SGA births.     

Wilms' tumour: a systematic review of risk factors and meta‐analysis

Chu A, Heck JE, Ribeiro KB, Brennan P, Boffetta P, Buffler P, Hung RJ. Wilms' tumour: a systematic review of risk factors and meta‐analysis. Paediatric and Perinatal Epidemiology 2010. Wilms' tumour comprises 95% of all renal cancers among children less than 15 years of age. The purpose of this review is to examine the existing literature on perinatal and environmental risk factors for Wilms' tumour. A search for epidemiological studies that examined risk factors for Wilms' tumour was undertaken in Medline, LILACS, ISI Web of Science and Dissertation Abstracts. A total of 37 studies, including 14 cohort, 21 case–control and 2 case–cohort studies, were identified that examined environmental and perinatal risk factors. Most studies were from Western Europe and North America, and among case–control studies, 16 used randomly selected population‐based controls. We observed a significantly increased risk of Wilms' tumour with maternal exposure to pesticides prior to the child's birth (OR = 1.37 [95% CI 1.09, 1.73]), high birthweight (OR = 1.36 [95% CI 1.12, 1.64]) and preterm birth (OR = 1.44 [95% CI 1.14, 1.81]), although the results regarding pesticide exposure may be subject to publication bias (Egger's test, P = 0.09). Further analyses to adjust for the heterogeneity in the results for high birthweight and preterm birth did not statistically change the significance of the results. Additionally, an increased though not statistically significant risk of Wilms' tumour was associated with maternal hypertension (OR = 1.30 [95% CI 0.99, 1.72]), and, compared with the first born, being a second or later birth was associated with a significantly decreased risk (OR = 0.82 [95% CI 0.71, 0.95]). This review suggests a role for several perinatal and environmental risk factors in the aetiology of Wilms' tumour.     

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.     

Cord blood lipid profile and associated factors: baseline data of a birth cohort study

The cord blood lipid profile may be associated with lifelong changes in the metabolic functions of the individual. The aim of the present study was for the first time in Iran to assess the cord blood lipid profile of neonates, as well as some of its environmental influencing factors. The subjects were 442 (218 boys and 224 girls) normal vaginal delivery newborns. Overall, 14.4% of neonates were preterm and the rest were full-term. In total, 9.2% (n = 35) of the full-term newborns were small-for-gestational-age (SGA), of which 16 had a ponderal index (PI) below the 10th percentile (SGA I) and 19 had a PI above the 10th percentile (SGA II), 5.5% (n = 21) were large-for-gestational-age (LGA), and the remainder were appropriate-for-gestational-age (AGA).Before becoming pregnant, 6.9% of mothers were underweight, 49.3% had normal body mass index (BMI), 39.4% were overweight and 4.4% were obese. Total and high-density lipoprotein cholesterol (HDL-C) in girls were significantly higher than in boys (80.3 +/- 33.3 and 31.1 +/- 9.9 vs. 73.3 +/- 23.1 and 28.8 +/- 8.7 mg/dL, respectively, P < 0.05). The mean apolipoprotein A (apoA) of neonates with underweight mothers was significantly lower, and the mean apoB level of those with overweight mothers was significantly higher than other neonates. The mean low-density lipoprotein cholesterol (LDL-C), HDL-C and apoA of the LGA newborns were significantly lower, and their apoB was significantly higher compared with AGA and SGA neonates. The SGA I neonates had significantly lower total cholesterol, LDL-C, HDL-C and apoA, as well as higher triglycerides, lipoprotein a and apoB than the SGA II group. The mean cord blood triglycerides of full-term neonates was significantly higher than preterm neonates (69.4 +/- 11.9 vs. 61.4 +/- 12.7 mg/dL, respectively, P = 0.04). A preconception maternal BMI of > or =25 kg/m(2) correlated significantly with the cord triglycerides (OR = 1.3, [95% CI 1.07, 1.5]) and with apoB (OR = 1.4, [95% CI 1.1, 1.5]). The BMI <18 of mothers before pregnancy correlated with low HDL-C (OR = 1.3, [95% CI 1.04, 1.7]). Birthweight correlated with high cord triglyceride level (SGA: OR = 1.4, [95% CI 1.1, 1.7]; LGA: OR = 1.6, [95% CI 1.3, 1.7] compared with AGA). These associations remained significant even after adjusting for the preconception BMI of mothers. Our findings reflect the possible interaction of environmental factors and fetal growth and the in utero lipid metabolism. Long-term longitudinal studies in different ethnicities would help to elucidate the relationship.     

Maternal use of nicotine replacement therapy during pregnancy and offspring birthweight: a study within the Danish National Birth Cohort

Lassen TH, Madsen M, Skovgaard LT, Strandberg‐Larsen K, Olsen J, Andersen A‐MN. Maternal use of nicotine replacement therapy during pregnancy and offspring birthweight: a study within the Danish National Birth Cohort. Paediatric and Perinatal Epidemiology 2010; 24: 272–281. Smoking is a well‐established risk factor for fetal growth restriction and other adverse pregnancy outcomes, and nicotine may be one of the chemical compounds that drive these associations. Nicotine replacement therapy (NRT) is a smoking cessation aid, which can facilitate smoking cessation. It is, however, unknown whether NRT used during pregnancy impairs fetal growth. The aim of this study was to estimate the association between the use of NRT during pregnancy and offspring birthweight. The study population consisted of 72 761 women enrolled in the Danish National Birth Cohort between 1996 and 2002. Information on NRT and potential confounders was obtained from two computer‐assisted telephone interviews conducted in the second and third trimesters, respectively. Multiple linear regression in a multilevel model was used to estimate the association between NRT use and birthweight adjusted for gestational age and potential confounders. The adjusted analyses showed no significant association between the duration of NRT use and birthweight (b = 0.25 g per week of NRT use [95% CI ?2.31, 2.81]) and neither was the type of NRT product (patch, gum, inhaler) associated with reduced birthweight. However, simultaneous use of more than one NRT product was associated with reduced birthweight (b = ?10.73 g per week of NRT use [95% CI ?26.51, 5.05]), although the association was not statistically significant. The results of this study suggest that maternal use of NRT in pregnancy does not seriously affect birthweight, but there could be a negative effect on birthweight associated with simultaneous use of more than one type of NRT product.     

Chlamydia trachomatis infection during pregnancy associated with preterm delivery: a population-based prospective cohort study

Chlamydia trachomatis infection is the most prevalent bacterial sexually transmitted infection and may influence pregnancy outcome. This study was conducted to assess the effect of chlamydial infection during pregnancy on premature delivery and birthweight. Pregnant women attending a participating midwifery practice or antenatal clinic between February 2003 and January 2005 were eligible for the study. From 4,055 women self-administered questionnaires and urine samples, tested by PCR, were analysed for C. trachomatis infection. Pregnancy outcomes were obtained from midwives and hospital registries. Gestational ages and birthweights were analysed for 3,913 newborns. The C. trachomatis prevalence was 3.9%, but varied by age and socio-economic background. Chlamydial infection was, after adjustment for potential confounders, associated with preterm delivery before 32 weeks (OR 4.35 [95% CI 1.3, 15.2]) and 35 weeks gestation (OR 2.66 [95% CI 1.1, 6.5]), but not with low birthweight. Of all deliveries before 32 weeks and 35 weeks gestation 14.9% [95% CI 4.5, 39.5] and 7.4% [95% CI 2.5, 20.1] was attributable to C. trachomatis infection. Chlamydia trachomatis infection contributes significantly to early premature delivery and should be considered a public health problem, especially in young women and others at increased risk of C. trachomatis infection.     

Risk factors in term children for visual impairment without a known prenatal or postnatal cause

Risk factors were studied for visual impairment in children without known pre- or postnatal cause, for a decrease of visual acuity. Children born at term 1979-98 and with a visual impairment were identified from the Swedish Register of Visually Impaired Children and data were linked with the Swedish Medical Birth Registry. Maternal characteristics such as maternal age, parity, maternal smoking habits in early pregnancy, maternal education, nationality, and subfertility were studied as well as maternal diagnoses such as pre-eclampsia, prolonged second stage of labour, abruptio placentae, and placenta praevia. Mode of delivery was analysed as well as birthweight, and birthweight in relation to gestational age. Abruptio placentae turned out to be the strongest risk factor (OR = 8.24 [95% CI 5.01, 13.51]). Smoking did not give a statistically significant increased risk. There is an increased risk with breech delivery (OR = 2.01 [95% CI 1.28, 3.17]). Pre-eclampsia was associated with an increased risk (OR = 2.22 [95% CI 1.46, 3.38]). There is also an increase in risk at low birthweight and small-for-gestational-age as well as birthweight > 4 kg and large-for-gestational-age. In this study we found that risk factors particularly worth noticing in term children with a presumed perinatal cause of visual impairment are abruptio placentae, pre-eclampsia, excessively low as well as excessively high birthweight, and breech delivery, a fact worth noticing in current discussion on risks, advantages or excessive exploitation of caesarean section.     

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.     

Prenatal and intrapartum events and sudden infant death syndrome

The purpose of this study was to evaluate specific pregnancy and labour and delivery events that may increase the risk of sudden infant death syndrome (SIDS). A matched case-control study was conducted in five counties in southern California, using California death certificate records. The sample consisted of 239 Caucasian, African-American, Hispanic and Asian mothers of SIDS infants and 239 mothers of control infants matched on sex, race, birth hospital and date of birth. Mothers participated in a detailed telephone interview and provided access to obstetric and paediatric records. More case than control mothers reported a family history of anaemia (OR=2.12, P < 0.001). Placental abruptions were strongly associated with SIDS (unadjusted OR=7.94, [95% CI 1.34,47.12]). There was an increased risk of SIDS death associated with maternal anaemia during pregnancy (OR=2.51, [95% CI 1.25,5.03]), while simultaneously adjusting for maternal smoking during pregnancy, maternal years of education and age, parity, infant birthweight, gestational age, medical conditions at birth, infant sleep position and post-natal smoking. Interactions of anaemia and prenatal smoking as well as anaemia and post-natal smoking were not statistically significant. There were no other statistically significant differences between case and control mothers for pregnancy conditions, labour and delivery events (e.g. caesarean sections, anaesthesia, forceps) or newborn complications (e.g. nuchal cord, meconium aspiration). Anaemia and placental abruptions were significantly associated with an increased risk of SIDS; both are circumstances in which a fetus may become hypoxic, thereby compromising the subsequent growth, development and ultimate survival of the infant.     

Effect of multiple micronutrient supplementation on pregnancy and infant outcomes: a systematic review

Supplementation with multiple micronutrients (MM) during pregnancy may result in improved pregnancy and infant outcomes. We conducted meta-analyses of randomised controlled trials that evaluated the effects of prenatal supplementation with MM (defined as containing at least five micronutrients and typically included iron or iron and folic acid). The outcomes of interest were low birthweight (<2500 g), birthweight, small-for-gestational age (SGA), gestational age, preterm birth (<37 weeks' gestation), stillbirth and neonatal death, maternal morbidity and mortality. We identified eligible studies through PubMed and EMBASE database searches. Meta-analyses were performed by pooling results for outcomes that were reported from more than one trial and sub-analyses were conducted to evaluate the effect of timing of intervention and amount of iron. We included published results from 16 trials in this review. Compared with control supplementation that was usually iron plus folic acid in most studies, MM supplementation resulted in a significant reduction in the incidence of low birthweight [pooled risk ratio (RR) 0.86; 95% confidence interval (CI) 0.81, 0.91] and SGA (pooled RR 0.83 [95% CI 0.73, 0.95]) and an increase in mean birthweight (weighted mean difference (WMD) 52.6 g [95% CI 43.2 g, 62.0 g]). There was no significant difference in the overall risk of preterm birth, stillbirth, and maternal or neonatal mortality, but we found an increased risk of neonatal death for the MM group compared with iron-folate in the subgroup of five trials that began the intervention after the first trimester (RR 1.38 [95% CI 1.05, 1.81]). None of the studies evaluated maternal morbidity. Compared with iron plus folic acid supplementation alone, prenatal maternal supplementation with MM resulted in a reduction in the incidence of low birthweight and SGA but increased risk of neonatal death in the subgroup of studies that began the intervention after the first trimester.     

Maternal ethnicity and pre-eclampsia in New York City, 1995-2003

Studies on ethnic differences in the risk of pre-eclampsia are limited. We linked birth records for 902,460 singleton births for the period 1995-2003 in New York City with hospital discharge data to evaluate the association between ethnicity and the risk of pre-eclampsia and compare risks between US-born and foreign-born women. Logistic regression models adjusted for maternal age, maternal education, parity, self-reported pre-pregnancy maternal weight, smoking during pregnancy and year of delivery were used to compare each ethnic group with non-Hispanic White women. The prevalence of pre-eclampsia in this study population was 3.2%. Among the major ethnic groups considered in our study, East Asian women had the lowest risk of pre-eclampsia (1.4%) and Mexican women had the highest risk (5.0%). Compared with non-Hispanic White women, there was a slightly decreased risk for East Asian women (adjusted OR = 0.8, [95% CI 0.7, 0.8]), similar risk for North African women (adjusted OR = 1.1, [95% CI 0.9, 1.3]), and increased risk for all other major ethnic groups (adjusted ORs: 1.3, 2.9), with the highest risk for Mexican women (adjusted OR = 2.9, [95% CI 2.7, 3.1]). No difference in risks was observed for US- vs. foreign-born women with the exception that foreign-born South-East Asian and Pacific Islanders had an increased risk of pre-eclampsia (adjusted OR = 1.8, [95% CI 1.0, 3.1]) relative to those born in the US. We concluded that there was ethnic heterogeneity in the development of pre-eclampsia among women in New York City and that Asian subgroups should be examined separately in future studies on ethnicity. Our results should contribute to screening for pre-eclampsia taking ethnic variation into account, and may help to suggest leads for the study of the aetiology of the condition.     

Association of periconceptional multivitamin use and risk of preterm or small-for-gestational-age births

The authors' objective was to determine the relation between periconceptional multivitamin use and the risk of small-for-gestational-age (SGA: <5th percentile; 5th-<10th percentiles) or preterm (<34 weeks; 34-<37 weeks) births. Women in the Pregnancy Exposures and Preeclampsia Prevention Study (1997-2001) reported at enrollment their regular multivitamin use in the past 6 months (n=1,823). Women were classified as users or nonusers in multinomial logistic models. After adjustment for race, age, education, enrollment gestational age, and household density, periconceptional multivitamin use was associated with a reduced risk of preterm births (<34 weeks) (odds ratio (OR)=0.29, 95% confidence interval (CI): 0.13, 0.64) and spontaneous preterm births (<34 weeks) (OR=0.40, 95% CI: 0.16, 0.99). Risk of SGA (<5th percentile) was marginally lower (OR=0.64, 95% CI: 0.40, 1.03) after adjustment for smoking, education, parity, enrollment gestational age, and body mass index. Prepregnancy body mass index modified this relation. Nonobese users had a reduction (OR=0.54, 95% CI: 0.32, 0.91) in risk of SGA (<5th percentile); there was no effect among obese women. There was no effect of multivitamin use on risk of preterm births (34-<37 weeks) or SGA (5th-<10th percentiles). Sensitivity analysis for unmeasured confounding by folate intake supported these findings. Study results indicate lower rates of severe preterm births and extreme SGA in women who report periconceptional vitamin use, although these should be considered cautiously until replicated.     

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.     

Secular trends in neonatal macrosomia in Berlin: influences of potential determinants

To investigate the trend in the prevalence of neonatal macrosomia and to evaluate the influences of potential determinants, key features of 206 308 hospital deliveries (97% of all) in Berlin in the years 1993-99, collected by the Berlin Medical Board, were analysed using SPSS 10.0. After exclusion of multiple births and preterm infants, there was a significant increase over 7 years (P < 0.01) in the prevalence of birthweights >or= 4000 g, maternal age >or= 30 years, height of >or= 165 cm, prepregnancy BMI (body mass index) >or= 26 kg/m2 and pregnancy weight gain> 16 kg, but no substantial trend in the prevalence of recognised diabetes or maternal smoking. The adjusted model (OR [95% CI]) for delivering a newborn >or= 4000 g was statistically significant for post-term delivery (2.56 [2.39, 2.75]), women aged >or= 30 years (1.06 [1.02-1.11]), >or= 165 cm tall (1.94 [1.87,2.01]), multiparae (1.98 [1.91, 2.05]), not smoking in pregnancy (2.03 [1.93, 2.14]), prepregnancy BMI >or= 26 compared with < 20 (4.01 [3.77, 4.26]), pregnancy weight gain >or= 16 kg compared with < 10 kg (3.37.[3.22, 3.53]) and for recognised diabetes (1.85.[1.69, 2.04]). It is speculated that this increase in the prevalence of neonatal macrosomia may contribute to the secular trend of overweight and obesity under affluent living conditions.     

Lifestyle factors,psychiatric and neurologic comorbidities,and drug use associated with incident seizures among adult patients with depression: a population-based nested case–control study

To investigate risk factors for incident seizures among adult patients with depression. We conducted a nested case–control analysis in adult patients with newly diagnosed depression, using data from the U.K.-based Clinical Practice Research Datalink. Among cases with incident seizures and matched controls, we estimated odds ratios (ORs) with 95 % confidence intervals (CIs) of potential risk factors for seizures as reported from data of the general population: underweight (body mass index <18.5 kg/m²), smoking, alcoholism, drug abuse, psychiatric or neurologic comorbidities, and concomitant use of drugs. Of 186,540 patients with depression, 1489 developed a seizure during follow-up. Being underweight (OR 1.67 [95 % CI 1.23–2.26]), a current smoker (OR 1.45 [95 % CI 1.26–1.67]), having alcoholism (OR 2.98 [95 % CI 2.56–3.47]), and drug abuse (OR 2.51 [95 % CI 1.94–3.24]), were associated with increased risks of seizures compared to normal weight, non-smoking, no alcoholism, and no drug abuse, respectively. Previous stroke/transient ischemic attack (OR 6.07 [95 % CI 4.71–7.83]) or intracerebral bleeding (OR 8.19 [95 % CI 4.80–13.96]), and comorbid dementia (OR 6.83 [95 % CI 4.81–9.69]), were strongly associated with seizures. Current use of cephalosporins (OR 2.47 [95 % CI 1.61–3.78]) and antiarrhythmics (OR 1.59 [95 % CI 1.26–2.01]) was associated with an increased risk of seizures compared to non-use. Among adult patients with depression, being underweight, smoking, alcoholism, and drug abuse, were associated with seizures. Remote stroke and comorbid dementia were strong risk factors for seizures. Current use of cephalosporins or antiarrhytmics was associated with an increased risk of seizures compared to non-use.     

The influence of maternal cigarette smoking, snuff use and passive smoking on pregnancy outcomes: the Birth To Ten Study

This article describes the patterns and effects of maternal snuff use, cigarette smoking and exposure to environmental tobacco smoke during pregnancy on birthweight and gestational age, in women living in Johannesburg and Soweto in 1990. A cohort of 1593 women with singleton live births provided information about their own and household members' usage of tobacco products during pregnancy. The women completed a questionnaire while attending antenatal services. Data on gestational age and birthweight were obtained from birth records. Women who smoked cigarettes or used snuff during pregnancy accounted for 6.1% and 7.5% of the study population respectively. The mean birthweight of non-tobacco users was 3148 g [95% CI 3123, 3173] and that of the smokers 2982 g [95% CI 2875, 3090], resulting in a significantly lower mean birthweight of 165 g for babies of smoking mothers (P = 0.005). In contrast, women using snuff gave birth to infants with a mean birthweight of 3118 g [95% CI 3043, 3192], which is a non-significant (P = 0.52) decrease (29.4 g) in their infants' birthweights compared with those not using tobacco. A linear regression analysis identified short gestational age, female infant, a mother without hypertension during pregnancy, coloured (mixed racial ancestry), and Asian infants compared with black infants, lower parity, less than 12 years of education and smoking cigarettes as significant predictors of low birthweight, while the use of snuff during pregnancy was not associated with low birthweight. The snuff users, however, had a significant shorter gestational age than the other two groups of women. The birthweight reduction adjusted for possible confounders was 137 g [95% CI 26.6, 247.3 (P = 0.015)] for cigarette smokers and 17.1 g [95% CI -69.5, -102.7, P = 0.69] for snuff users respectively, compared with the birthweight of non-tobacco users. Among women who did not smoke cigarettes or use snuff, exposure to environmental tobacco smoke did not result in significant effects on the birthweight of their infants. In conclusion, infants of cigarette smokers had significantly lower birthweights than those of non-tobacco users or snuff users who are exposed to nicotine during pregnancy. Passive smoking did not affect birthweight significantly in this population.     

Fetal growth, maternal prenatal smoking, and risk of invasive meningococcal disease: a nationwide case-control study

BACKGROUND: The prenatal period may be important for susceptibility to infections. We evaluated whether low birthweight, prematurity, and prenatal maternal smoking were associated with increased risk of invasive meningococcal disease. METHODS: We linked the Danish nationwide National Registry of Patients, the Birth Registry, and social registries to obtain data on fetal growth and social factors on 1921 cases of meningococcal disease hospitalized between 1 January, 1980 and 31 December, 1999 (median age 31 months, interquartiles 13-65 months) and 37 451 population controls. The impact of maternal smoking was examined in a subsample of 462 cases and 9240 controls born after 1990, when data on smoking became available in the Birth Registry. RESULTS: The adjusted odds ratios (OR) of meningococcal disease associated with low birthweight (<2500 g) varied between 1.6 (95% CI: 1.1, 2.3) in infants <12 months to 1.5 (95% CI: 1.0, 2.3) in children >60 months of age at hospitalization for meningococcal disease. Premature children had an increased risk of meningococcal disease during the first year of life only (adjusted OR = 1.3, 95% CI: 1.1, 1.9). The effect of low birthweight was very similar among mature and premature children. The adjusted OR for maternal smoking was 1.8 (95% CI: 1.4, 2.2). CONCLUSIONS: Low birthweight is associated with an increased risk of meningococcal disease throughout childhood, while an effect of prematurity persists only for 12 months. Maternal prenatal smoking was associated with the risk of meningococcal disease.