Factors associated with mental health of young children during the COVID-19 pandemic in the Netherlands.

BACKGROUND: The COVID-19 pandemic and accompanying societal measures have impacted children and their families all over the world. Little is known about the factors associated with mental health outcomes in young children (i.e., 1 to 6 years old) during the pandemic. The current study aimed to examine associations with potential risk and protective factors, i.e., direct COVID-19 exposure factors as well as within-family characteristics. METHODS: Caregivers of children aged 1-6 years old were recruited in the Netherlands to participate in an ongoing longitudinal research project. In the current study, baseline data-collected during the 1st year of the pandemic-are reported. The final sample consisted of 2762 caregivers who answered questionnaires assessing negative and positive dimensions of their children's mental health (i.e., anxiety, depressive symptoms, anger, sleep problems, positive affect, and self-regulation). Furthermore, caregivers provided information regarding: (1) Direct COVID-19 related factors, i.e., parental infection and death of a family member or close friend due to COVID-19, (2) Family related COVID-19 factors, i.e., parental perceived impact of the pandemic and COVID-19 related parent-child emotion regulation strategies (i.e., active, avoidant and information-focused strategies), (3) General caregiver's distress, i.e., parental mental health, parental feelings of rejection towards their child. Regression analyses were used to examine associations with children's mental health. RESULTS: Direct COVID-19 related factors were not associated with more mental health problems in the children, though parental COVID-19 infections were related with less anger in children. Family related COVID-19 factors and caregiver's distress were related with children's mental health. Higher parental perceived negative impact of the pandemic, lower parental perceived positive impact of the pandemic, more avoidant as well as more active and information-focused parent-child emotion regulation strategies, more caregiver's mental health problems and more parental feelings of rejection towards their child were related with more mental health problems in the child. CONCLUSION: Direct exposure to COVID-19 was not related with more mental health problems in the child. Family related COVID-19 factors and caregiver's distress appear to play a more important role for young children's mental health. Findings may inform prevention and intervention programs for potential future global crises as well as other stressful events.

Is maternal negative affectivity related to psychosocial behavior of preterm and term-born toddlers through mother-child interaction?

Introduction: Children born moderately to late preterm (MLP) are more prone to psychosocial difficulties than their term-born counterparts. Maternal negative affectivity (NA)-a relatively stable personality trait characterized by the tendency to experience negative thoughts, feelings and emotions-has been related to more psychosocial problems in their offspring, and to a lower quality of mother-child interactions. As MLP children seem more sensitive to their early caregiving environment, they might be more affected by maternal NA and interaction style than their term-born peers. The current study investigated whether maternal NA predicted child's psychosocial outcomes through quality of mother-child interaction, and if these associations differed between MLP and term-born children. Methods: The sample consisted of 108 MLP and 92 term-born children and their mothers. At 18 months corrected age, maternal NA was measured using a self-report questionnaire and mother-child interaction was observed during two structured tasks. Five subscales of mother-child interaction were assessed: negative interaction, reciprocal engagement, emotional support, maternal stimulation and mother-led interaction. At 24 months corrected age, social-emotional difficulties, internalizing, and externalizing problems were assessed using mother-report. Results: For MLP children, maternal NA directly, positively, predicted social-emotional difficulties (b = 0.57) and internalizing problems (b = 0.45), but no mediation effect of mother-child interaction was found. For term-born children, no direct effect but a mediation effect of mother-led interaction was found. Higher levels of maternal NA predicted less mother-led interaction which in turn predicted more problems. Birth status did not moderate any of the relationships, showing that the differences in patterns of effects found within the MLP and term-born group did not reach statistical significance. Discussion: Maternal NA was found to be a risk factor for psychosocial outcomes in toddlers, either directly for MLP children or indirectly through mother-led interaction for term-born children. These findings suggest that the process through which maternal NA affects psychosocial outcomes may be different for MLP and term-born children. However, as the examined moderation effects of birth status did not reach statistical significance, more research using larger sample sizes is needed to study mother-child interaction in greater detail.

Effects of tocolysis with nifedipine or atosiban on child outcome: follow-up of the APOSTEL III trial.

OBJECTIVE: To compare the long-term effects of tocolysis with nifedipine or atosiban on child outcome at age 2.5-5.5 years. DESIGN: The APOSTEL III trial was a multicentre randomised controlled trial that compared tocolysis with nifedipine or atosiban in 503 women with threatened preterm birth. Neonatal outcomes did not differ between both treatment arms, except for a higher incidence of intubation in the atosiban group. METHODS: Parents were asked to complete four questionnaires regarding neurodevelopment, executive function, behaviour problems and general health. MAIN OUTCOME MEASURES: The main long-term outcome measure was a composite of abnormal development at the age of 2.5-5.5 years. RESULTS: Of the 426 women eligible for follow-up, 196 (46%) parents returned the questionnaires for 115 children in the nifedipine group and 110 children in the atosiban group. Abnormal development occurred in 32 children (30%) in the nifedipine group and in 38 children (38%) in the atosiban group (OR 0.74, 95% CI 0.41-1.34). The separate outcomes for neurodevelopment, executive function, behaviour, and general health showed no significant differences between the groups. Sensitivity analysis for all children of the APOSTEL III trial, including a comparison of deceased children, resulted in a higher rate of healthy survival in the nifedipine group (64 versus 54%), but there was no significant difference in the overall mortality rate (5.4 versus 2.7%). There were no significant subgroup effects. CONCLUSION: Outcomes on broad child neurodevelopment, executive function, behaviour and general health were comparable in both groups. Neither nifedipine nor atosiban can be considered as the preferred treatment for women with threatened preterm birth. TWEETABLE ABSTRACT: Nifedipine- and atosiban-exposed children had comparable long-term outcomes, including neurodevelopment, executive function and behaviour.

Risk and protective factors for pre- and postnatal bonding.

Since disturbances in the mother-child bond increase the risk of negative consequences for child development, it is important to identify risk and protective factors for bonding as well as longitudinal associations. Previous research has used different bonding instruments during pregnancy and the postnatal phase, leading to inconsistent results. In the current study, the same instrument was used during the various phases. In a large, community-based sample (N = 793), general information, feelings of pre- and postnatal bonding (Pre- and Postnatal Bonding Scale), depressive symptoms (Edinburgh Postnatal Depression Scale), and partner support (subscale Tilburg Pregnancy/Postnatal Distress Scale) were measured at both 32 weeks of pregnancy and 8 months postnatally. Partner support was found to be a protective factor for suboptimal pre- and postnatal bonding, as was the engagement with fetal movements for prenatal bonding. High maternal educational level was a risk factor for suboptimal prenatal bonding, as were depressive symptoms for suboptimal postnatal bonding. The associations between most prenatal determinants and postnatal bonding were mediated by prenatal bonding, which underlines the importance of promoting prenatal bonding. Professionals in clinical practice should be aware of partner support, engagement with fetal movements, and postnatal depressive symptoms: All these factors offer opportunities for improving the bonding processes.

Dado que las perturbaciones en la unión afectiva entre madre y niño aumentan el riesgo de consecuencias negativas para el desarrollo del niño, es importante identificar los factores de riesgo y de protección de la unión afectiva, así como también las asociaciones longitudinales. La investigación anterior ha utilizado diferentes instrumentos para la unión afectiva durante el embarazo y la fase postnatal, lo que ha llevado a resultados inconsistentes. En el presente estudio, el mismo instrumento se usó durante las diferentes fases. En un grupo muestra grande con base comunitaria (N = 793), se midieron, tanto a las 32 semanas del embarazo como a los ocho meses después del nacimiento, la información general, los sentimientos sobre la unión afectiva pre- y postnatal (Escala de Unión Afectiva Pre- y Postnatal), los síntomas depresivos (Escala de Edimburgo de la Depresión Postnatal), y el apoyo de la pareja (Sub-escala Tilburg sobre el Embarazo / Escala de la Angustia Postnatal). Se detectó el apoyo de la pareja como un factor de protección para la unión afectiva pre- y postnatal por debajo del punto óptimo, lo cual también se dio con respecto a la interacción con los movimientos fetales en la unión afectiva prenatal. El alto nivel de educación materna fue un factor de riesgo para la unión afectiva prenatal sub-óptima, así como los síntomas depresivos lo fueron para la unión afectiva postnatal sub-óptima. Las asociaciones entre la mayoría de los determinantes prenatales y la unión afectiva postnatal fueron mediadas por la unión afectiva prenatal, lo cual subraya la importancia de promover la unión afectiva prenatal. Los profesionales de la práctica clínica deben estar conscientes del apoyo de la pareja, la interacción con los movimientos fetales, y los síntomas depresivos postnatales: todos estos factores ofrecen oportunidades de mejorar los procesos de afectividad.

Etant donné que les perturbations du lien mère-enfant augmentent le risque de conséquences négatives pour le développement de l'enfant il est important d'identifier les facteurs de risque et les facteurs de protection du lien, ainsi que les associations longitudinales. Jusqu'à présent les recherches ont utilisé divers instruments de lien durant la grossesse et la phase postnatale, menant à des résultats n'étant pas uniformes. Dans cette étude, le même instrument a été utilisé durant les phases multiples. Chez un grand échantillon représentatif de la communauté (N = 793), les renseignements généraux, les sentiments de lien pré- et postnatal (Echelle Pré- et Postnatale) les symptômes dépressifs (Echelle de Dépression Postnatale d'Edinbourg) et le soutien du conjoint (sous-échelle de grossesse Tilburg/Echelle de Détresse Postnatale) ont été mesurés à la fois à 32 semaines de grossesse et à huit mois postnatalement. Le soutien du conjoint s'est avéré être une facteur de protection pour le lien sous-optimal pré- et postnatal, tout comme l'était le fait de s'engager avec les mouvements du foetus pour le lien prénatal. Un niveau élevé d'éducation chez la mère était un facteur de risque de lien prénatal sous-optimal, tout comme l'étaient des symptômes dépressifs pour le lien sous-optimal postnatal. Les associations entre la plupart des déterminants prénataux et le lien postnatal étaient toutes influencées par le lien prénatal, ce qui souligne l'important de la promotion du lien prénatal. Les professionnels en pratique clinique devraient être vigilants quant au soutien du partenaire, au fait de s'engager avec les mouvements du foetus et aux symptômes dépressifs postnataux: tous ces facteurs offrent des possibilités d'amélioration des processus de lien.

Pessary for prevention of preterm birth in twin pregnancy with short cervix: 3-year follow-up study.

OBJECTIVE: A recent randomized clinical trial (ProTWIN) showed that a cervical pessary prevented preterm birth and improved neonatal outcome in women with multiple pregnancy and cervical length (CL) < 38 mm. In this follow-up study, the long-term developmental outcome of these children was evaluated at 3 years' corrected age. METHODS: This was a follow-up study of ProTWIN, a multicenter trial conducted between 2009 and 2012 in which asymptomatic women with a multiple pregnancy were randomized to placement of a cervical pessary or no intervention. Current follow-up and analysis were limited to mothers with a mid-trimester CL < 38 mm (78 women (157 children) in the pessary group and 55 women (111 children) in the control group). At 3 years of corrected age, surviving children were invited for a Bayley Scales of Infant and Toddler Development-third edition (Bayley-III) assessment. Death after randomization or neurodevelopmental disability (Bayley-III score of ≤ 85, 1 SD below mean) rates were compared between the pessary and control groups, according to the intention-to-treat principle and using multiple imputation for missing data. Mean Bayley-III scores in surviving children were also assessed. A linear mixed-effects model was used to adjust for correlation between children of one mother. RESULTS: From the time of entry in the ProTWIN trial until follow-up at 3 years of age, a total of 27 children had died (six (5%) in the pessary vs 21 (26%) in the control group; odds ratio (OR), 0.13; 95% CI, 0.04-0.48). Bayley-III outcomes were collected for 173/241 (72%) surviving children (114 (75%) in the pessary vs 59 (66%) in the control group). The cumulative incidence of death or survival with a neurodevelopmental disability was 12 (10%) in the pessary vs 23 (29%) in the control group (OR, 0.26; 95% CI, 0.09-0.73). No statistical or clinically relevant differences were found with respect to cognitive, language and motor development among surviving children between the groups. Comparable results were found after multiple imputation. CONCLUSION: In women with twin pregnancy and a CL < 38 mm, the use of a cervical pessary strongly improved survival of the children without affecting neurodevelopment at 3 years' corrected age. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Parenting stress in mothers after very preterm birth and the effect of the Infant Behavioural Assessment and Intervention Program.

OBJECTIVE: Purpose of this study was to examine maternal parenting stress as a secondary outcome of the Infant Behavioural Assessment and Intervention Program (IBAIP). METHODS: In a randomized controlled trial 86 very preterm infants and their parents were assigned to the intervention group and 90 to the control group. Maternal parenting stress was assessed with the Dutch version of the Parenting Stress Index at 12 and 24 months post term. RESULTS: Mothers in the intervention group mothers assessed their infants as happier and less hyperactive/distractible compared with the control group mothers. However, mothers in the intervention group reported more feelings of social isolation. CONCLUSIONS: The IBAIP appears to have made mothers more satisfied about their infants' mood and distractibility, but also may have evoked more feelings of social isolation. Next to long-term evaluation of the development in very preterm born children, follow-up on functioning of their parents is important.

Delayed cord clamping in preterm infants delivered at 34 36 weeks' gestation: a randomised controlled trial.

BACKGROUND: Even mild iron deficiency and anaemia in infancy may be associated with cognitive deficits. A delay in clamping the cord improves haematocrit levels and results in greater vascular stability and less need for packed cell transfusions for anaemia in the first period after birth. Follow-up data on haemoglobin levels after the neonatal period were not available. OBJECTIVE: To provide neonatal and follow-up data for the effects of early or delayed clamping of the cord. METHODS: 37 premature infants (gestational age 34 weeks, 0 days-36 weeks, 6 days) were randomly assigned to one of two groups in the first hour after birth, and at 10 weeks of age. In one group the umbilical cord was clamped within 30 seconds (mean (SD) 13.4 (5.6)) and in the other, it was clamped at 3 minutes after delivery. In the neonatal period blood glucose and haemoglobin levels were determined. At 10 weeks of age haemoglobin and ferritin levels were determined. RESULTS: The late cord-clamped group showed consistently higher haemoglobin levels than the early cord-clamped group, both at the age of 1 hour (mean (SD) 13.4 (1.9) mmol/l vs 11.1 (1.7) mmol/l), and at 10 weeks (6.7 (0.75) mmol/l vs 6.0 (0.65) mmol/l). No relationship between delayed clamping of the umbilical cord and pathological jaundice or polycythaemia was found. CONCLUSION: Immediate clamping of the umbilical cord should be discouraged.

Behavioural and emotional problems in very preterm and very low birthweight infants at age 5 years.

BACKGROUND: Children born very preterm (VP; <32 weeks' gestation) or with very low birth weight (VLBW, <1500 g; hereafter called VP/VLBW) are at risk for behavioural and emotional problems during school age and adolescence. At school entrance these problems may hamper academic functioning, but evidence on their occurrence at this age in VP/VLBW children is lacking. AIM: To provide information on academic functioning of VP/VLBW children and to examine the association of behavioural and emotional problems with other developmental problems assessed by paediatricians. DESIGN, SETTING AND PARTICIPANTS: A cohort of 431 VP/VLBW children aged 5 years (response rate 76.1%) was compared with two large national samples of children of the same age (n = 6007, response rate 86.9%). OUTCOME MEASURES: Behavioural and emotional problems measured by the Child Behavior Checklist (CBCL), and paediatrician assessment of other developmental domains among VP/VLBW children. RESULTS: The prevalence rate of a CBCL total problems score in the clinical range was higher among VP/VLBW children than among children of the same age from the general population (13.2% v 8.7%, odds ratio 1.60 (95% confidence interval 1.18 to 2.17)). Mean differences were largest for social and attention problems. Moreover, they were larger in children with paediatrician-diagnosed developmental problems at 5 years, and somewhat larger in children with severe perinatal problems. CONCLUSION: At school entrance, VP/VLBW children are more likely to have behavioural and emotional problems that are detrimental for academic functioning. Targeted and timely help is needed to support them and their parents in overcoming these problems and in enabling them to be socially successful.

Development and evaluation of a follow up assessment of preterm infants at 5 years of age.

BACKGROUND: Long term follow up shows a high frequency of developmental disturbances in preterm survivors of neonatal intensive care formerly considered non-disabled. AIMS: To develop and validate an assessment tool that can help paediatricians to identify before 6 years of age which survivors have developmental disturbances that may interfere with normal education and normal life. METHODS: A total of 431 very premature infants, mean gestational age 30.2 weeks, mean birth weight 1276 g, were studied at age 5 years. Children with severe handicaps were excluded. The percentage of children with a correctly identified developmental disturbance in the domains cognition, speech and language development, neuromotor development, and behaviour were determined. RESULTS: The follow up instrument classified 67% as optimal and 33% as at risk or abnormal. Of the children classified as at risk or abnormal, 60% had not been identified at earlier follow up assessments. The combined set of standardised tests identified a further 30% with mild motor, cognitive, or behavioural disturbances. The paediatrician's assessment had a specificity of 88% (95% CI 83-93%), a sensitivity of 48% (95% CI 42-58%), a positive predictive value of 85% (95% CI 78-91%), and a negative predictive value of 55% (95% CI 49-61%). CONCLUSIONS: Even after standardised and thorough assessment, paediatricians may overlook impairments for cognitive, motor, and behavioural development. Long term follow up studies that do not include detailed standardised tests for multiple domains, especially fine motor domain, may underestimate developmental problems.

Does the Edinburgh Postnatal Depression Scale measure anxiety?

OBJECTIVE: The existence of a separate anxiety and depression dimension within the Edinburgh Postnatal Depression Scale (EPDS) has been reported previously. However, the concurrent validity of this anxiety subscale was never evaluated. We investigated whether (1) this existence of an anxiety subscale could be confirmed and (2) it more highly correlated with other measures of anxiety than the total EPDS. METHODS: The SCL-90-R, the EPDS, and the State-Trait Anxiety Inventory (STAI) were filled out by 197 pregnant women. A principal component analysis (PCA) was used for confirmation of the subscales and correlations were computed between the (subscales of the) EPDS and the other measures of anxiety. RESULTS: The existence of an anxiety scale within the EPDS was confirmed. However, this subscale did not yield higher correlations with other measures of anxiety than did the total EPDS. CONCLUSION: Investigators using the EPDS to screen for depression should realise that the instrument does not exclusively measure depression. It seems that both anxiety symptoms and depressive symptoms are more accurately measured when using the total 10-item EPDS than when using the subscales.

Low maternal free thyroxine concentrations during early pregnancy are associated with impaired psychomotor development in infancy.

BACKGROUND: Maternal thyroid function during early pregnancy is an important determinant of early fetal brain development because the fetal thyroid is unable to produce any T4 before 12-14 weeks' gestation. Overt maternal hypothyroidism as seen in severe iodine-deficient areas is associated with severely impaired neurological development of the offspring. At present, it is not known whether low free T4 (fT4) levels during pregnancy in healthy women from iodine sufficient areas may affect fetal neurodevelopment. METHODS: Neurodevelopment was assessed at 10 months of age in a cohort of 220 healthy children, born after uncomplicated pregnancies and deliveries, using the Bayley Scales of Infant Development. Maternal TSH, fT4 and TPO antibody status were assessed at 12 and 32 weeks' gestation. Maternal gestational fT4 concentration was defined as an independent parameter for child development. RESULTS: Children of women with fT4 levels below the 5th (< 9.8 pmol/l, n = 11) and 10th (< 10.4 pmol/l, n = 22) percentiles at 12 weeks' gestation had significantly lower scores on the Bayley Psychomotor Developmental Index (PDI) scale at 10 months of age, compared to children of mothers with higher fT4 values (t test, mean difference: 14.1, 95% confidence interval (CI): 5.9-22 and 7.4, 95% CI: 1.1-13.9, respectively). At 32 weeks' gestation, no significant differences were found. In the group of women with the lowest 10th percentile fT4 concentrations at 12 weeks' gestation, a positive correlation was found between the mothers' fT4 concentration and children's PDI scores (linear regression, R: 0.46, P = 0.03). After correction for confounding variables, a fT4 concentration below the 10th percentile at 12 weeks' gestation was a significant risk factor for impaired psychomotor development (RR): 5.8, 95% CI: 1.3-12.6). CONCLUSIONS: Low maternal plasma fT4 concentrations during early pregnancy may be an important risk factor for impaired infant development.

Thyroid function in preterm newborns; is T4 treatment required in infants < 27 weeks' gestational age?

Thyroid hormones are essential for brain maturation. Very preterm infants, who are at risk of neurodevelopmental disabilities also have low T4 and FT4 values in the first weeks after birth. This transient hypothyroxinemia may in part be causal to the neurodevelopmental problems. We have carried out a randomised, double-blind, placebo-controlled trial with T4 in 200 infants < 30 weeks' gestation. In the study groups as a whole (n = 100 in the T4 group, n = 100 in the Placebo group), no clear effect of T4 administration was found. In this study we examined whether gestational age influenced the effect of T4 administration. The T4- and placebo groups were subdivided into 4 groups according to gestational age. FT4-values during the first weeks after birth were lowest in the youngest gestational age group in the T4 as well as in the placebo group. In this group with infants < 27 weeks' gestation mental developmental outcome at 2 years of age was significantly better than in the placebo group of the same gestational age. There was also a trend towards a better psychomotor and neurological outcome. Beyond 27 weeks' gestation, no clear effect of T4 could be found; on the contrary, a possible harmful effect on mental developmental outcome might be the result. In conclusion. T4 treatment possibly improves developmental outcome in infants < 27 weeks' gestation, but seems not necessary beyond this gestational age.

Maternal thyroid peroxidase antibodies during pregnancy: a marker of impaired child development?

Women with antibodies against the enzyme thyroid peroxidase [TPO-Ab; formerly microsomal antibodies (MsAb)] are at particular risk for developing postpartum thyroid dysfunction; the latter is significantly associated with postpartum depression. Although the negative effect of postpartum maternal depression on child development is well documented, the consequences of elevated titers of TPO-Ab during pregnancy and subsequent postpartum thyroid dysfunction on child development are not known. In a prospective study of a cohort of 293 pregnant women, the occurrence of TPO-Ab during gestation, thyroid dysfunction, and depression was investigated. Five years after delivery, child development was assessed in 230 children of the original cohort using the Dutch translation of the McCarthy Scales of Children's Abilities. Children of women with TPO-Ab during late gestation (n = 19, with normal thyroid function) had significantly lower scores (by t test) on the McCarthy Scales of Children's Abilities than antibody-negative women. The difference on the General Cognitive Scale, which reflects IQ scores, was substantial (10.5 points; t = 2.8; P = 0.005). After correction for possibly confounding variables, maternal TPO-Ab during gestation was found to be the most important factor related to the scores on the General Cognitive Scale (odds ratio = 10.5; 95% confidence interval = 3-34; P = 0.003). We conclude that children of pregnant women who had elevated titers of TPO-Ab but normal thyroid function are at risk for impaired development.

Development after prenatal exposure to cocaine, heroin and methadone.

In Amsterdam a longitudinal, prospective and multidisciplinary study on the development of infants of drug-dependent mothers (IDDM) was started in 1983: 35 IDDM and 35 reference infants were originally enrolled. The drug-dependent women had used combinations of methadone, heroin, cocaine and other drugs during pregnancy. Of the IDDM, 80% had to be treated pharmaceutically for neonatal abstinence symptoms (NAS). Physical, neurological, cognitive and the socio-emotional development of the children were studied regularly from birth until 5.5 years of age. Differences between the reference group and the IDDM were found most clearly in cognitive development. The IDDM also had more behavioural problems at some of the ages studied. No group differences were seen in motor development. So far the results of the study show that IDDM and their caregivers need extra support in order to improve early communication and the children's cognitive development.

Neonatal behavior after drug dependent pregnancy.

Neurobehavioural development of 35 infants of drug dependent mothers was compared with the development of 37 reference infants as part of a prospective longitudinal research project. Infants of drug dependent mothers had more poor responses than the other children on neurological examination. This difference is significant only when data of infants of drug dependent mothers born at full term are analysed. Two tailed testing indicated that significantly more infants of drug dependent mothers than reference children had electro-encephalograms rated as suspect or abnormal. By the end of the first month the infants of drug dependent mothers tended to be more active, and they had worse scores than the reference children on the neonatal behavioural assessment scale. Analysing data only of infants born at full term, the groups differ significantly on the interactive items. The results of this study show that even after treatment for the neonatal abstinence syndrome, infants of drug dependent mothers seem to differ from comparison children, which could indicate later developmental problems.

Behaviour in first year after drug dependent pregnancy.

Neurobehavioural development of a group of 35 infants of drug dependent mothers and of a reference group of 37 infants was compared. Two tailed testing showed that at the age of 3 months the infants of drug dependent mothers seemed to be more active than the reference group; at 6 months, however, no difference was found. On the infant behaviour temperament questionnaire, infants of drug dependent mothers tended to have slightly better scores for 'duration of orienting' at the age of 9 months; five other dimensions of behaviour did not differ between the groups. The Bayley scales of infant development and neurological examination according to the method of Touwen did not show any significant differences among the groups at the ages of 6 or 12 months. At 12 months infants of drug dependent mothers had slightly but not significantly worse results on electroencephalography. Studied with multidisciplinary measurements, the development of infants of drug dependent mothers does not seem to diverge particularly from the development of the reference group.