Does perinatal asphyxia contribute to neurological dysfunction in preterm infants?

Background

Children born preterm are known to be at risk for neurodevelopmental disorders. The role of perinatal asphyxia in this increased risk is still a matter of debate.

Aim

To analyze the contribution of perinatal asphyxia in a population of preterm infants admitted to a secondary paediatric setting to neurological dysfunction in the first months after birth and to the development of cerebral palsy.

Methods

17 preterm infants with perinatal asphyxia born before 35 weeks postmenstrual age (PMA) and 34 carefully matched preterm controls without asphyxia were studied. Neuromotor outcome was examined by means of three assessments of the quality of general movements (GM) at “preterm” (around 34 weeks PMA), “writhing” (around term age) and “fidgety” GM age (around 3 months post term). Follow-up until at least 18 months corrected age focused on the presence of cerebral palsy (CP).

Results

GM-quality of infants with asphyxia and of those without did not differ. Multivariate analysis revealed that abnormal GMs at “preterm” age were associated with respiratory problems, those at “writhing” age with none of the assessed risk factors, and those at “fidgety” age with the severity of periventricular leukomalacia (PVL) on neonatal ultrasound scan.Perinatal asphyxia was not associated with the development of CP. CP was associated with PVL and the presence of abnormal GMs at “fidgety” age.

Conclusion

Perinatal asphyxia in preterm infants is not associated with an increased risk for neurodevelopmental problems including CP. Respiratory problems during the neonatal period are associated with PVL and adverse neurological outcome.     

Parenting stress in mothers of preterm infants during early infancy

Objective

Mothers of preterm infants during the first year of life may experience stresses greater that those found in mothers of term infants. The aim of the study was to determine the levels of parenting stress and psychological well-being in mothers of very preterm babies in comparison to a control group of term mothers.

Methods

One hundred and five mothers who delivered 124 babies at ≤ 30 weeks gestation were recruited together with 105 mothers who delivered 120 babies at term. At 4 months of age (corrected for prematurity for the preterm babies), the mothers completed the Parenting Stress Index Short Form, the Edinburgh Postnatal Depression Scale (EPDS), the Dyadic Adjustment Scale (DAS) and the Short Temperament Scale for Infants (STSI). The preterm and term groups were compared.

Results

Questionnaires were returned from 86 of the preterm mothers and 97 of the term mothers. The mean Total Stress score for the preterm and term groups was 67.0 and 63.79 respectively (P = 0.32) with 17% of the preterm and 9% of the term group having high scores (P = 0.135). There were no differences of the EPDS and the DAS between the groups. The temperament of the preterm infants was similar to the term infants. For both groups, scores on the EPDS, DAS and the STSI were independent predictors of Total Stress scores on multiple regression analysis.

Conclusion

Parenting stress in mothers of preterm infants during early infancy does not appear to be greater than that in mothers of infants born at term. For both groups of mothers, depression symptoms, marital satisfaction and infant temperament were independent risk factors for high levels of parenting stress.     

Parenting stress in mothers of very preterm infants — Influence of development,temperament and maternal depression

Objective

To measure levels of parenting stress and postnatal depression in mothers of very preterm infants in comparison with mothers of infants born at term is the objective of this study. The study also aimed to explore factors associated with parenting stress in the mothers of the preterm infants.

Methods

One hundred and five mothers who delivered 124 babies at ≤ 30 weeks gestation were enrolled together with 105 term mothers who delivered 120 babies. At one year of age (corrected for prematurity for the preterm cohort), the mothers completed the Parenting Stress Index Short Form (PSI), the Edinburgh Postnatal Depression Scale (EPDS) and the Short Temperament Scale for Toddlers. The infants had neurodevelopmental assessment. The preterm and term groups were compared.

Results

Questionnaires were completed by 101 of the preterm mothers and 98 of the term mothers. The mean PSI Total Stress score was significantly higher for the preterm mothers (70.28 vs 64.52, p = 0.022), with 19% of the preterm group and 9% of the term group having high scores (p = 0.038).There was no group difference on the EPDS or measures of temperament, with disability being greater in the preterm infants. For the preterm group, maternal depression and infant temperament were independent predictors of Total Stress scores on multivariate analysis.

Conclusions

Parenting stress in mothers of preterm infants at one year of age is significantly greater than that found in mothers of term infants. For preterm mothers, symptoms of depression and infant temperament are independent risk factors for higher levels of parenting stress.     

Differential associations between maternal scaffolding and toddler emotion regulation in toddlers born preterm and full term

Background

Parental “scaffolding” behavior has been associated with developmental outcomes in at-risk children.

Aims

Because there are limited empirical data regarding how scaffolding is associated with emotion-based developmental skills, the purpose of this study was to compare associations between maternal verbal scaffolding and toddler emotion regulation, including fewer displays of negative affect and increased contentment and enjoyment during play, in toddlers born preterm and full term.

Study design

This study was a cross-sectional cohort design. Maternal and toddler behavior was assessed during 5 min of videotaped free play with standardized toys.

Subjects

131 toddlers (18–22 months) and their mothers were included (77 born preterm; 54 born full term).

Outcome measures

Toddler emotion regulation, negative affect, and dyadic mutual enjoyment were coded from videotaped play.

Results

The association between maternal scaffolding and emotion regulation was different for dyads with a toddler born preterm versus full term, wherein the association was positive for toddlers born preterm and non-significant for toddlers born full term. Similarly, the association between maternal scaffolding and negative affect was different for the two groups: negative for toddlers born preterm and non-significant for toddlers born full term. Finally, the association between maternal scaffolding and mutual enjoyment was positive for toddlers born preterm and non-significant for toddlers born full term.

Conclusions

Our findings highlight early differences in mother-child interactive style correlates of children born preterm compared to those born full term. Maternal scaffolding behavior may be uniquely associated with emotion regulation and a positive dyadic encounter for toddlers born preterm.     

Genre du bébé et trouble de la personnalité borderline maternel : quel impact sur l’interaction mère-bébé à 3 mois du postpartum ?

Background and aim

This research aims to study mother-infant interactions at 3 months postpartum using the Still Face Face-to-Face Paradigm comparing two groups, mothers with borderline personality disorder and controls. We hypothesized that dyadic interactions with mothers afflicted with the disorder would be significantly different from those without psychopathology, and that these differences would vary according to infant gender.

Methods

Nineteen dyads of mothers with Borderline Personality Disorder and 41 with control mothers were filmed using the Still Face Paradigm. Behaviors of both partners were studied using microanalytic coding with the Maternal and Infant Regulation Scoring System.

Results and conclusion

Our analysis shows that both partners react to the stress induced by the Still Face episode (the paradigm is divided in three phases, 2 minutes of spontaneous interaction face-to-face, 2 minutes of maternal Still Face per se, and 2 minutes of reuniting interactive play). Infants of mothers with Borderline Personality Disorder show less gaze focused on mother than their control counterparts; infant girls regulate themselves more than boys and mothers with psychopathology demonstrate more tactile stimulation of their infants (touch, tickle, etc.). Our research illustrates how different dyadic adaptive mechanisms exist according to maternal psychopathology and infant gender, and suggests that as early as 3 months postpartum, infants are already trying to adapt to maternal functioning and dysfunctional interactions through self-regulatory mechanisms. This begs for further research exploring as precisely as possible interactive mechanisms both early in life and in longitudinal studies.     

Maternal sensitivity moderates the impact of prenatal anxiety disorder on infant mental development

Background

Animal studies have shown that postnatal rearing style can modify the association between prenatal stress exposure and offspring neurodevelopmental outcomes. However, little is known about how parenting quality impacts the association between maternal prenatal anxiety and development in human infants.

Aim

This prospective study examined the impact of maternal prenatal anxiety disorder and maternal caregiving sensitivity on cognitive and psychomotor development in healthy, full-term, 7-month-old infants.

Measures

Women completed a clinical interview during the third trimester of pregnancy to assess anxiety symptoms meeting DSM-IV diagnostic criteria. At infant age 7 months, maternal sensitivity to infant distress and non-distress were observed and coded during the still-face procedure. Maternal postnatal (concurrent) anxiety and depression were also assessed at this time. Infant mental and psychomotor development was assessed at infant age 7 months using the Bayley Scales of Infant Development II.

Results

Analyses were based on 77 mother-infant dyads. Maternal sensitivity to infant distress moderated the association between maternal prenatal anxiety disorder and infant mental development, F (1, 77) = 5.70, p = .02. Whereas there was a significant positive association between sensitivity and mental development among infants whose mothers were anxious during pregnancy, sensitivity had little impact on mental development among infants of control (non-anxious) women. Results were independent of prenatal depression and postnatal anxiety and depression. A caregiving moderation effect was not found for infant psychomotor development, p > .10.

Conclusions

These findings are consistent with a cumulative risk model suggesting that maternal prenatal anxiety and quality of maternal care act in concert to shape infant outcomes.     

Declining cognitive development from 8 to 18 months in preterm children predicts persisting higher parenting stress

Background

Higher parenting stress in mothers of children born very preterm may be in part a response to poorer neurobehavioral development, reflecting realistic concerns in addition to adaptation to the trauma of preterm delivery. To our knowledge, there are few longitudinal studies of parenting stress that have addressed child cognitive competence.

Aims

To examine parenting stress in preterm and full-term children at 8 and 18 months corrected chronological age (CCA), in relation to child cognitive development and behavior.

Subjects

Participants were N = 152 children (98 preterm born ≤ 32 weeks gestation, and 54 full-term) seen at 8 and 18 months CCA, and the primary caregiver parent.

Study design/Outcome measures

The Parenting Stress Index questionnaire was completed by a parent, child interactive behavior was videotaped, and the Bayley Scales of Infant Development (BSID II, Mental Development Index; MDI) were administered at both ages.

Results

Total Parenting Stress was higher in preterm than full-term children at 8 and 18 months CCA (p < .02), accounted for primarily by the Child domain. Hierarchical regression showed (after controlling for neonatal risk, number of children in the home, child interactive behavior and maternal education) that decreasing Bayley MDI scores from 8 to 18 months CCA predicted higher parenting stress for preterm children. For full-term children, number of children in the home and child interactive behavior predicted parental stress at 18 months.

Conclusion

Higher parenting stress persisting to 18 months CCA in preterm children may partly reflect realistic parental concerns with their child's development.     

Hypothalamic-pituitary-adrenal (HPA) axis function in 3-month old infants with prenatal selective serotonin reuptake inhibitor (SSRI) antidepressant exposure

Background

Prenatal exposure to stress and selective serotonin reuptake inhibitors (SSRIs) alter hypothalamic-pituitary-adrenal (HPA) stress reactivity in offspring, however, the effects of combined exposure to HPA activity in human infants is unknown.

Objective

To examine HPA basal levels and stress responsiveness in 3-month olds with prenatal exposure to SSRIs.

Methods

Salivary cortisol levels in infants of SSRI treated mothers (n = 31, mean exposure 230.2 ± 72.2 days) were compared with non-SSRI exposed (n = 45) infants in response to a challenge (infant-controlled habituation task) and under basal conditions in the late afternoon/early evening. Mode of feeding, to account for possible postnatal drug exposure via breast milk, as well as measures of pre and postnatal maternal mood, were included as covariates.

Results

Lower post-stress cortisol levels were observed in non-SSRI exposed/non-breastfed infants compared with non-SSRI exposed infants who were breastfed at 3 months of age. Stress reactivity patterns among SSRI exposed infants did not differ with mode of feeding. The cortisol reactivity slope (CRS) was significantly lower among non-SSRI exposed non-breastfed infants compared with non-SSRI exposed breastfed infants. Early evening basal cortisol levels were lower in SSRI exposed infants than in non-SSRI exposed infants, controlling for maternal mood and mode of feeding. Postnatal SSRI exposure (infant SSRI drug levels) via breast milk was not associated with stress or basal cortisol levels. Total cortisol, reflected by the AUC measure, did not differ significantly between exposure groups.

Conclusions

Prenatal SSRI exposure altered HPA stress response patterns and reduced early evening basal cortisol levels. Stress challenge HPA response differences only became apparent when the moderating effect of method of feeding was accounted for. These findings suggest an early “programming” effect of antenatal maternal mood, prenatal SSRI exposure and postnatal maternal care giving on the HPA system.     

Maternal life events during pregnancy and offspring language ability in middle childhood: The Western Australian Pregnancy Cohort Study

Background

There is accumulating evidence for a link between maternal stress during pregnancy and later behavioural and emotional problems in children. Little research has examined other developmental outcomes.

Aim

To determine the effect of maternal stress during pregnancy on offspring language ability in middle childhood.

Study design

Longitudinal pregnancy cohort-study.

Subjects

A total of 2900 mothers were recruited prior to the 18th week of pregnancy, delivering 2868 live births. The language ability of just under half of the offspring cohort (n = 1309; 45.6% of original sample) was assessed in middle childhood (Mean age = 10;7, Standard deviation = 0;2, range: 9;5-11;11).

Outcome measures

Language ability was measured using the Peabody Picture Vocabulary Test-Revised (PPVT-R). The main predictor variable was the frequency of 10 typically ‘stressful’ life events experienced by mothers during early and/or late pregnancy. Children were allocated to four groups according to whether they were exposed to high maternal stress (≥ 2 life events) during early pregnancy only, late pregnancy only, both, or neither.

Results

Mixed-effects regression analyses revealed no association between the maternal experience of two or more stressful life events at any time-point during pregnancy and PPVT-R scores. Repeating the regression analyses with more lenient (≥ 1 life events) or strict (≥ 3 life events) thresholds for defining high-levels of maternal stress did not alter the pattern of findings.

Conclusions

Maternal experience of typically stressful life events during pregnancy has a negligible effect on vocabulary development to middle childhood.     

Standard fortification of preterm human milk fails to meet recommended protein intake: Bedside evaluation by Near-Infrared-Reflectance-Analysis

Background

Protein content of preterm human milk (HM) is relatively low and extremely variable among mothers: thus, recommended protein intake is rarely met.

Objectives

To evaluate in a NICU setting if HM protein content after standard fortification meets the recommended intake, and also to check the effect of fortification on the osmolality of HM, as an index of feeding intolerance.

Methods

Protein content of 34 preterm HM samples was evaluated by a bedside technique (Near-Infrared-Reflectance-Analysis — NIRA); osmolality was also checked. Seventeen samples were fortified with Aptamil BMF, Milupa (Group A) and 17 with FM85, Nestlé (Group B). Fortification was performed as recommended by the manufacturer (“full fortification [FF]”) and also with a lower amount of fortifier (“low-dose fortification [LF]”). After fortification, actual protein content was calculated and compared to that needed to meet recommended intake (2.33-3 g/dl), and osmolality was measured.

Results

After FF, protein content was above 3 g/dl in none of the samples, and below 2.33 g/dl in 16/34 samples (11 in Group A, 5 in Group B). After LF, protein content was above 3 g/dl in none of the samples and below 2.33 g/dl in 32/34 samples (15 in Group A, 17 in Group B). Osmolality exceeded 400 mOsm/kg in 19 samples after FF (10 in Group A, 9 in Group B) and in 2/34 samples after LF (1 in each group).

Conclusion

HM protein content after standard fortification fails to meet the recommended intake for preterm infants in approximately half of the cases.     

Is smoking in pregnancy an independent predictor of academic difficulties at 14 years of age? A birth cohort study

Background

Studies of the effects of maternal smoking during pregnancy have reported inconsistent findings in relation to measures of offspring cognitive functioning. Few studies, however, have examined learning outcomes in adolescents, as opposed to IQ.

Aim

To examine the association between maternal smoking during pregnancy and academic performance among adolescent offspring.

Study design

Population-based birth cohort study.

Subjects

7223 mothers and children were enrolled in the Mater-University of Queensland Study of Pregnancy in Brisbane (Australia) from 1981 to 1984. Analyses were restricted to the 4294 mothers and children for whom all information was reported at 14-year follow-up.

Outcome measures

Reports of academic performance of 14-year-old offspring in English, Science and Mathematics with different patterns of maternal smoking (never smoked, smoked before and/or after pregnancy but not during pregnancy, or smoked during pregnancy).

Results

Low academic achievement was more common only in those whose mothers had smoked during pregnancy. Effect sizes were, however, small. The adjusted mean difference in total learning score for smoking before and/or after pregnancy but not during pregnancy, and for smoking during pregnancy were − 0.18 (− 0.58, 0.22) and − 0.40 (− 0.69, − 0.12). Similarly, the adjusted odds ratios were 0.9 (0. 65, 1.24) and 1.35 (1.07, 1.70).

Conclusion

Maternal smoking during pregnancy is a preventable prenatal risk factor associated with small decrements in offspring academic performance that continue into adolescence.     

Parental body size and early weight and height growth velocities in their offspring

Background

Whereas weight or height at a given age are the results of the cumulative growth experience, growth velocities allows the study of factors affecting growth at given ages.

Aim

To study the relationships between parental height and body mass index (BMI) and offspring's height and weight growth during infancy and childhood.

Study design

From the FLVSII population-based study, 235 parent-child trios belonging to 162 families examined in 1999.

Outcome measures

From medical records and previous FLVS examinations, child's height and weight history were reconstructed. Weight and height growth velocities from birth to seven years were estimated from a modelling of individual growth curve and correlated with parent's body size in 1999.

Results

Ponderal index and length at birth were significantly associated with maternal but not paternal BMI and height. In the first six months, height growth velocity was significantly associated with maternal stature (at three months: 0.12 ± 0.05 and 0.02 ± 0.05 cm/month for a 10 cm difference in maternal and paternal height respectively) and weight growth velocity with paternal BMI (at three months: 5.7 ± 2.8 and 1.9 ± 2.3 g/month for a difference of 1 kg/m² in paternal and maternal BMI respectively). Between two and five years, height growth velocity was more significantly associated with paternal height whereas weight growth velocity was more closely associated with maternal BMI.

Conclusions

Early childhood growth is characterised by alternate periods associated specifically with maternal or paternal BMI and height. This novel finding should trigger the search for specific genetic, epigenetic or environmentally shared factors from the mothers and fathers.     

Maternal interactive behaviour as a predictor of preschoolers' attachment representations among full term and premature samples

Background

Associations between maternal sensitivity and child attachment have been established in many samples, but the strength of the association varies across populations. The sensitivity–attachment link has never been examined at the level of representations nor among premature samples.

Objective

The present study is aimed at exploring associations between maternal interactive behaviour and children's attachment representations in a population of preterm and full-term infants.

Method

Maternal interactive behaviour was assessed at 6 and 18 months (Ainsworth Sensitivity Scale & Care Index) and children's attachment representations were measured at 42 months (Attachment Story Completion Task) in a sample of preterm (N = 48) and full-term (N = 23) infants.

Results

Maternal unresponsiveness at 6 months and sensitivity at 18 months explained 54% of the variance of disorganized attachment representations in the full-term group but was not significantly related to attachment patterns in the preterm group.

Conclusion

These results corroborate previous work on the causes of disorganized attachment and also point to the need to consider the development of attachment differently for children evolving in specific developmental contexts. They especially stress the importance of distinguishing between risk factors associated with the mother as opposed to the child.     

Maternal anxiety is related to infant neurological condition, paternal anxiety is not

Background

Parental anxiety and stress may have consequences for infant neurological development.

Aims

To study relationships between parental anxiety or well-being and infant neurological development approximately one year after birth.

Study design

Longitudinal study of a birth cohort of infants born to subfertile couples. Subjects: 206 parent-child dyads.

Outcome measures

Infant neurology was assessed with the Touwen Infant Neurological Examination (TINE) at 10 months and a developmental questionnaire at 12 months. Parental measures included trait anxiety measured by the State-Trait Anxiety Inventory (STAI) and well-being measured by the General Health Questionnaire (GHQ).

Results

Maternal trait anxiety was associated with a less optimal neurological condition (r_s = − 0.19, p < 0.01) of the infant. This association persisted after adjusting for confounders and results were confirmed by the outcome of the developmental questionnaire. Paternal trait anxiety and parental well-being were not related to the infant's neurodevelopmental outcome.

Conclusions

Infants of mothers with high trait anxiety have an increased vulnerability to develop a non-optimal nervous system. The association may be mediated in part by early programming of monoaminergic systems. Future research should include an exploration of specific windows of vulnerability to maternal anxiety.     

Are former late-preterm children at risk for child vulnerability and overprotection?

Background

Parent perception of child vulnerability (PPCV) and parent overprotection (POP) are believed to have serious implications for age appropriate cognitive and psychosocial development in very low birth weight preterm children.

Aim

With recent concerns about suboptimal developmental outcomes in late-preterm children, this study was aimed at examining the relationship between history of late-preterm birth (34-36 6/7 weeks gestation), and PPCV, POP, and healthcare utilization (HCU).

Study design

This was a cross-sectional observational design.

Participants

Study participants were mothers of 54 healthy singleton children recruited from community centers including Women and Children Clinics (WIC), primary care clinics and daycare centers in the upper Midwest region.

Outcome measures

Outcome measures included Forsyth Child Vulnerability Scale (CVS), Thomasgard Parent Protection Scale (PPS) scores, and healthcare utilization (HCU). Potential covariates included history of life-threatening illness, child and maternal demographics, and maternal stress and depression using the Center for Epidemiologic Studies Depression Scale (CESD).

Results

HCU (p = 0.02) and the PPS subscales of supervision (p = 0.003) and separation (p = 0.03) were significant predictors of PPCV in mothers of 3-8years old children with late-preterm history. Age of the child (p = 0.008) and CVS scores (p = 0.005) were significant predictors of POP. Maternal age (p = 0.04), stress (p = 0.04), and CVS scores (p = 0.003) were significant predictors of HCU. Dependence, a subscale of the PPS, correlated with the child's age and gender even after controlling for age.

Conclusion

History of late-preterm did not predict MPCV, MOP, or HCU in healthy children. Future research is needed in larger more diverse samples to better understand causal relationships and develop strategies to lessen risks of MPCV and MOP.     

A comparison of executive function in very preterm and term infants at 8 months corrected age

Background

Executive function (EF) emerges in infancy and continues to develop throughout childhood. Executive dysfunction is believed to contribute to learning and attention problems in children at school age. Children born very preterm are more prone to these problems than their full-term peers.

Aim

To compare EF in very preterm and full-term infants at 8 months after expected date of delivery.

Subjects

37 very preterm infants without identified disabilities, and 74 gender and age matched healthy full-term infants. The very preterm infants were all ≤ 32 weeks gestation and < 1250 g birthweight.

Outcome measures

EF tasks which measured working memory, inhibition of distraction, and planning at 8 months after expected date of delivery.

Results

The very preterm infants performed significantly more poorly than the full-term infants on all measures of executive function. No significant differences were found between very preterm and full-term infants on any of potentially confounding variables of, infant temperament, maternal education, family income and maternal psychological wellbeing. Very preterm infants had significantly lower scores on the Mental Development Index (MDI) and Psychomotor Development Index (PDI) on the Bayley Scales of Infant Development (BSID II), however when this was partialled out the differences in EF scores remained. Medical complications, lower birthweight and lower gestation age were all found to adversely affect the performance of very preterm infants on executive function tasks.

Conclusion

Very preterm infants performed more poorly than full-term infants on measures of EF. Further follow up studies are required to investigate whether EF measures in infancy can predict learning and attention outcome at school age.     

Sensorimotor skills associated with motor dysfunction in children born extremely preterm

Background

Children born prematurely, despite being free of intellectual and sensorineural deficits, are at risk of motor dysfunction.

Aim

To investigate the association of sensorimotor processing skills and Developmental Coordination Disorder (DCD) in “apparently normal” extreme preterm children.

Study design

In a matched case-control study, 50 preterm children born less than 29 weeks or birthweight < 1000 g, with an IQ > 85 and no identified sensorineural disability, were assessed at 8 years of age along with 50 gender and birth date matched classroom controls born at full term. A battery of sensorimotor tests was administered, which examined visual-motor, visual perception, tactile perception, kinaesthesia, and praxis.

Results

For preterm children with DCD (n = 21), significantly lower scores were found for the visual processing and praxis tests, with the exception of verbal command, in comparison to those 29 preterm children without DCD and term controls (median visual perception scores were 92, 96 and 108 respectively; design copying was 0.07, 0.46 and 0.95; constructive praxis was 0.09, 0.27 and 0.63; and sequencing praxis was 0.14, 0.73 and 0.96). There were no difference on the tactile sensitivity and kinaesthetic processing tests.

Conclusions

Preterm children with DCD have difficulty with visual processing tasks. Praxis or motor planning poses a particular challenge for them. Motor dysfunction in extremely preterm children was related to poorer visual processing and motor planning and may relate to a cognitive processing problem.     

Longitudinal study of smoking cessation before pregnancy and children's cognitive abilities at 56 months of age

Background

An inverse relationship exists between the rates of maternal smoking during pregnancy and children's cognitive abilities. The effect of maternal cessation of smoking before pregnancy on child's cognitive development is less clear.

Aims

To study whether maternal cessation of smoking before pregnancy is associated with children's cognitive abilities.

Study design and subjects

The original cohort included all 1535 live-born infants admitted to the neonatal wards during 1 year and 658 randomly recruited non-admitted infants. The present study sample comprised 1019 (68.2%) children of the original sample born at term and free of any major impairment followed up to 56 months.

Outcome measures

Child's general reasoning, visual-motor integration, verbal competence, and language comprehension at 56 months of age.

Results

The results showed that children whose mothers smoked > 10 cigarettes per day before pregnancy but none during pregnancy, fared 12.07 (95% confidence interval [CI]: 4.07 to 20.08) and 11.23 (95% CI: 2.81 to 19.66) age-standardized points poorer in general reasoning and in language comprehension tests, respectively, than children of never-smokers. All results were adjusted for the sex, gestational age-adjusted birth weight, multiple/singleton pregnancy, birth order, preeclampsia, maternal diabetes, admission to neonatal ward, 5-minute Apgar score (< 7), breastfeeding, parental level of education, maternal age, BMI at the end of pregnancy and single parenting.

Conclusions

Heavy smoking before pregnancy is associated with children's lower cognitive abilities even if the mother has quit smoking before pregnancy. Identification and intervention of heavy smoking women of fertile age would potentially improve not only their odds to become pregnant but also benefit the offspring's cognitive functioning.     

Maternal vitamin B-12 and folate status during pregnancy and excessive infant crying

Background

The etiology of excessive infant crying is largely unknown. We hypothesize that excessive infant crying may have an early nutritional origin during fetal development.

Aims

This study is the first to explore whether (1) maternal vitamin B-12 and folate status during pregnancy are associated with excessive infant crying, and (2) whether and how maternal psychological well-being during pregnancy affects these associations.

Study design

Women were approached around the 12th pregnancy week to complete a questionnaire (n = 8266) and to donate a blood sample (n = 4389); vitamin B-12 and folate concentrations were determined in serum. Infant crying behavior was measured through a postpartum questionnaire (± 3 months; n = 5218).

Subjects

Pregnant women living in Amsterdam and their newborn child.

Outcome measures

Excessive infant crying, defined as crying ≥ 3 h/day on average in the past week.

Results

Multiple logistic regression analysis was performed for 2921 (vitamin B-12) and 2622 (folate) women.Vitamin B-12 concentration (categorized into quintiles) was associated with excessive infant crying after adjustment for maternal age, parity, ethnicity, education, maternal smoking and psychological problems (OR[95%CI]: Q1 = 3.31[1.48-7.41]; Q2 = 2.50[1.08-5.77]; Q3 = 2.59[1.12-6.00]; Q4 = 2.77[1.20-6.40]; Q5 = reference). Stratified analysis suggested a stronger association among women with high levels of psychological problems during pregnancy. Folate concentration was not associated with excessive infant crying.

Conclusions

First evidence is provided for an early nutritional origin in excessive infant crying. A low maternal vitamin B-12 status during pregnancy could, in theory, affect infant crying behavior through two potential mechanisms: the methionine-homocysteine metabolism and/or the maturation of the sleep-wake rhythm.