Caren I. Lanting

Neurological condition in 18-month-old children perinatally exposed to polychlorinated biphenyls and dioxins

The neurological optimality of 418 Dutch children was evaluated at the age of 18 months, in order to determine whether prenatal and breast milk mediated exposure to polychlorinated biphenyls (PCBs) and dioxins affected neurological development. Half of the infants were breast-fed, the other half were formula-fed. PCB concentrations in cord and maternal plasma were used as a measure of prenatal exposure to PCBs. To measure postnatal exposure, PCB and dioxin congeners were determined in human milk and in formula milk. After adjusting for covariates, transplacental PCB exposure was negatively related to the neurological condition at 18 months. Although greater amounts of PCBs and dioxins are transferred via nursing than via placental passage, an effect of lactational exposure to PCBs and dioxins could not be detected. We even found a beneficial effect of breast-feeding on the fluency of movements. We conclude that transplacental PCB passage has a small negative effect on the neurological condition in 18-month-old toddlers.

Neurological condition in 42-month-old children in relation to pre- and postnatal exposure to polychlorinated biphenyls and dioxins.

Adverse neurological effects of exposure to PCBs have been found up to 18 months of age. Now we report on the effect of pre- and postnatal exposure to PCBs and dioxins on the neurological condition at 42 months of age. For this purpose, PCB levels were determined in cord and maternal plasma, and used as a measure of prenatal exposure. Breast milk was analyzed for PCBs and dioxins. In addition, PCBs were determined in plasma sampled from the child at 42 months of age. We evaluated the neurological condition of 394 children using the Touwen/Hempel method. After adjustment for covariates, neither prenatal PCB exposure nor postnatal exposure to PCBs and dioxins was found to be related to the neurological condition at 42 months of age.

Clustering of Socioeconomic, Behavioural, and Neonatal Risk Factors for Infant Health in Pregnant Smokers

Background Tobacco smoking is a major cause of morbidity and mortality, including during pregnancy. Although effective ways of promoting smoking cessation during pregnancy exist, the impact of these interventions has not been studied at a national level. We estimated the prevalence of smoking throughout pregnancy in the Netherlands and quantified associations of maternal smoking throughout pregnancy with socioeconomic, behavioural, and neonatal risk factors for infant health and development. Methodology/Principal Findings Data of five national surveys, containing records of 14,553 Dutch mothers and their offspring were analyzed. From 2001 to 2007, the overall rate of smoking throughout pregnancy fell by 42% (from 13.2% to 7.6%) mainly as a result of a decrease among highly educated women. In the lowest-educated group, the overall rate of smoking throughout pregnancy was six times as high as in the highest-educated group (18.7% versus 3.2%). Prenatal tobacco smoke exposure was associated with increased risk of extremely preterm (≤28 completed weeks) (OR 7.25; 95% CI 3.40 to 15.38) and small-for-gestational age (SGA) infants (OR 3.08; 95% CI 2.66 to 3.57). Smoking-attributable risk percents in the population (based on adjusted risk ratios) were estimated at 29% for extremely preterm births and at 17% for SGA outcomes. Infants of smokers were more likely to experience significant alcohol exposure in utero (OR 2.08; 95%CI 1.25 to 3.45) and formula feeding in early life (OR 1.91; 95% CI 1.69 to 2.16). Conclusions The rates of maternal smoking throughout pregnancy decreased significantly in the Netherlands from 2001 to 2007. If pregnant women were to cease tobacco use completely, an estimated 29% of extremely preterm births and 17% of SGA infants may be avoided annually.

Breastfeeding and neurological outcome at 42 months

This study investigated the effect of early feeding mode on the neurological condition at 42 months. For this purpose, healthy pregnant women were recruited in Groningen and Rotterdam, The Netherlands. Children were healthy and born at term. At 42 months, the children were neurologically examined by means of the Touwen/Hempel technique. In addition to the clinical diagnosis, the neurological findings were interpreted in terms of optimality. Special attention was paid to the quality of movements in terms of fluency. In total, 200 (51%) exclusively breastfed (for ≥ 6 weeks) and 194 (49%) formula‐fed children were studied. Twelve (3%) 42‐month‐old children were considered to be neurologically mildly abnormal and 1 child was diagnosed as abnormal. No effect of the type of feeding was found on the clinical diagnosis or the neurological optimality. After adjustments for study centre and social, obstetric, perinatal and neonatal neurological differences, a beneficial effect of breastfeeding on the fluency of movements was found (odds ratio for non‐optimal fluency 0.56; 95% confidence interval 0.37‐0.85). The prolongation of full breastfeeding beyond 6 weeks did not influence the quality of movements. In conclusion, among Dutch preschool children, there was a small advantageous effect of full breastfeeding during the first 6 weeks of life on the fluency of movements.

Breastfeeding duration related to practised contraception in the Netherlands

Aim: The aim of this study was to gain insight into contraception practised and related to breastfeeding duration.

Exposure to tobacco smoke and infant crying: Tobacco and excessive infant crying

Aim: To examine the association of excessive infant crying with maternal smoking during and after pregnancy, paternal smoking, and smoking by other people in the living environment of the infant. Methods: We collected data on infant crying and smoking in a Dutch national sample of 5845 infants aged 0–3 mo (response 62.8%). We defined excessive crying as crying over 3 h a day on more than 3 d of the preceding week. Results: The prevalence rate of excessive crying was 4.0% (95% CI 3.5 to 4.5%). Excessive crying occurred more frequently among infants of fathers smoking 15+ cigarettes/d (odds ratio (OR) 1.99, 95% CI 1.38 to 2.86) and of mothers smoking 10+ cigarettes/d during pregnancy (OR 1.86, 95% CI 1.02 to 3.42). Infants whose parents were heavy current smokers or whose mothers had been so during pregnancy had a 69% higher prevalence of excessive crying than infants of non‐smoking parents (rates: 6.3% and 3.7%, respectively; odds ratio 1.80; 95% CI 1.26 to 2.57).