Piccolipiù, a multicenter birth cohort in Italy: protocol of the study

Background

The fetal and infant life are periods of rapid development, characterized by high susceptibility to exposures. Birth cohorts provide unique opportunities to study early-life exposures in association with child development and health, as well as, with longer follow-up, the early life origin of adult diseases. Piccolipiù is an Italian birth cohort recently set up to investigate the effects of environmental exposures, parental conditions and social factors acting during pre-natal and early post-natal life on infant and child health and development. We describe here its main characteristics.

Methods/design

Piccolipiù is a prospective cohort of expected 3000 newborns, who will be recruiting in six maternity units of five Italian cities (Florence, Rome, Trieste, Turin and Viareggio) since October 2011. Mothers are contacted during pregnancy or at delivery and are offered to participate in the study. Upon acceptance, their newborns are recruited at birth and followed up until at least 18 years of age. At recruitment, the mothers donate a blood sample and complete a baseline questionnaire. Umbilical cord blood, pieces of umbilical cord and heel blood spots are also collected. Postnatal follow-up currently occurs at 6, 12, and 24 months of age using on-line or postal self administered questionnaire; further questionnaires and medical examinations are envisaged. Questionnaires collect information on several factors, including mother’s and/or child’s environmental exposures, anthropometric measures, reproductive factors, diet, supplements, medical history, cognitive development, mental health and socioeconomic factors. Health promotion materials are also offered to parents.

Discussion

Piccolipiù will broaden our understanding of the contribution of early-life factors to infant and child health and development. Several hypotheses on the developmental origins of health can be tested or piloted using the data collected from the Piccolipiù cohort. By pooling these data with those collected by other existing birth cohorts it will be possible to validate previous findings and to study rare exposures and outcomes.

Associations of prenatal mercury exposure from maternal fish consumption and polyunsaturated fatty acids with child neurodevelopment: a prospective cohort study in Italy

BACKGROUND

Mercury is a neurotoxin, and limited prenatal exposure to it can affect long-term child neurodevelopment. However, results of epidemiologic studies of such exposure have been inconsistent. We examined the association of prenatal mercury exposure from maternal fish consumption with child neurodevelopment in northern Italy.

METHODS

A population-based cohort of 606 children and their mothers was studied from pregnancy to age 18 months. Mercury levels were measured in maternal hair and blood during pregnancy and in umbilical cord blood and breast milk. Levels of polyunsaturated fatty acids (PUFAs) were measured in maternal serum. Maternal and child intakes of fish were assessed by using a food frequency questionnaire. The Bayley Scales of Infant and Toddler Development, Third Edition (BSID-III) was used to evaluate child neurodevelopment. Multivariate linear regression was used to examine the association of mercury exposure with BSID-III scores, after controlling for maternal fish intake, PUFAs during pregnancy, and several other confounders.

RESULTS

Mean weekly fish intake during pregnancy was less than 2 servings. Mercury concentrations in biological samples were low (mean, 1061 ng/g in hair) and moderately correlated with fish intake, particularly of carnivorous species. Maternal ω-3 PUFA concentrations were poorly correlated with fish intake. Maternal intelligence quotient (IQ) and child intake of fish were significantly associated with neurodevelopment scores. In multivariate models, the level of Hg exposure was not associated with neurodevelopmental performance at 18 months.

CONCLUSIONS

In this Italian population, neurodevelopment at 18 months was associated with child intake of fresh fish and maternal IQ rather than with mercury exposure. The expected beneficial effect of maternal fish intake (from maternal ω-3 PUFAs) was not found.

[Interrater reliability of the Bayley III test in the Italian Northern-Adriatic Cohort II]

OBJECTIVE

to assess the agreement between two trained psychologists who administered the Bayley Scale of Infant Development III (BSID III) to detect neurodevelopment deficits in a cohort of children within the Northern Adriatic Cohort II (NAC II) longitudinal study, which aims to assess the impact of mercury exposure through food consumption of mothers in pregnancy on their children's neurodevelopment.

DESIGN

a reliability study was carried out. Two trained psychologists administered the test, each one scoring the test independently, and serving as the primary examiner for half of the sample and as the observer for the other half.

SETTING AND PARTICIPANTS

a sample of 53 children of 18 months of age was enrolled consecutively within the Italian NAC II, and tested using the Bayley Scale of Infant Development III (BSID III) to detect neurodevelopment deficits.

MAIN OUTCOME MEASURES

the cognitive, language, and motor scales of the BSID III were evaluated and the respective Intraclass Correlation Coefficients (ICC) were calculated.

RESULTS

overall, the ICCs for the cognitive and language scales were very high (≥0.98), while the ICCs for the motor scales were slightly lower, ranging from 0.86 (gross motor, scaled) to 0.97 (fine motor, scaled), but still higher than 0.80, reported as the general acceptable benchmark for psychological testing.

CONCLUSION

the interrater reliability of all BSID III scales for this sample of 18-month-old children is very high and assures comparable results between the two psychologists involved in the Italian NAC II study. The reasons are a common training, the joint evaluation of many children during the preliminary phase of the study, the discussion of inconsistent results, but also the "go no-go" nature of the items in BSID III.

Analysis of motivations that lead women to participate (or not) in a newborn cohort study

BACKGROUND

Little is known about reasons that influence parents' decision to participate in studies enrolling healthy children. The aim of this observational study was to verify the reasons that lead pregnant women to give their consent or to refuse participation to a newborn cohort study with a long follow up time.

METHODS

To prospectively investigate the reasons that lead women to participate, to refuse the participation or to withdraw from a newborn cohort study, three different questionnaires were administered to pregnant women contacted or enrolled in the Phime cohort study, carried out in an Italian Hospital from 2007 to 2010.

RESULTS

Phime study participation was refused by 304 women and 145 withdrew their consent during the follow up. All these women filled in the related questionnaires. Within 632 mothers in follow up at 18 months, 430 filled in the questionnaire on motivation to participate: 97% stated that the main reason was to contribute to research; 96% and 90% stated that they wanted to benefit future babies' and mothers' health. Ninety-six percent of women would appreciate to know the results of analysis carried out on biological samples collected and of the overall study results. One third of the mothers (37%) wanted to be involved in the definition of future similar studies, bringing their experience and their views. Within the 304 women who refused participation, 56% stated that the study was too demanding, 26% was not interested in participating and 18% was concerned about the need to collect biological samples and to be submitted to neurocognitive tests. Fifty-two percent of 145 women who withdrew after enrollment stated that the study was too demanding (52%), and 6% was concerned about the biological samples collection.

CONCLUSIONS

The altruistic reason appears to be the main reported by women to decide to participate in a newborn cohort study. The fact that the study was too demanding and the need to collect biological samples are important reasons that lead women to refuse participation or to withdraw from the study. An adequate communication on these aspects should minimize difficulties in enrolment and losses to follow up.

Neuropsychological assessment at school-age and prenatal low-level exposure to mercury through fish consumption in an Italian birth cohort living near a contaminated site

The relative effects of prenatal and postnatal low-level mercury exposure and fish intake on child neurodevelopment are still controversial. Limited evidence is available from Mediterranean populations. In this prospective study, we measured the Verbal and Performance IQ in Italian children at school-age who were resident in an area declared as a National contaminated site because of mercury pollution, taking into account the possible beneficial effect of fish consumption and potential confounders. A mother-child cohort made up of 242 children was established at birth in Northeastern Italy in 2001. Their mothers were interviewed approximately 2 months after delivery to determine type, quantity, and origin of fish consumed during pregnancy and about a number of mother, child and family characteristics. Total mercury (THg) and methyl mercury (MeHg) were assessed in maternal hair and breast milk and in the child's hair. When children reached 7-9 years of age, 154 (63.6%) parents gave consent to participate in a follow-up evaluation. On that occasion, a child's hair sample was collected to determine the current concentration of THg, mothers were asked to complete a self-administered questionnaire, and children underwent neuropsychological testing. Verbal IQ, performance IQ and full scale IQ were measured by the Wechsler Intelligence Scale for Children (WISC III) administered by psychologists at school or local health centers. Demographic, socioeconomic and lifestyle information, medical information of the child's family and the child's dietary habits were collected using a questionnaire filled in by mothers. Multivariable linear regression models were used to evaluate the association between prenatal THg exposure through fish consumption of mothers in pregnancy and children's IQ after adjustment for possible confounders such as fish consumption of mothers in pregnancy, child's fish consumption at follow-up, child's birthweight, maternal cigarette smoking during pregnancy, house size and property place of residence during pregnancy and gender. THg in the child's hair at 7 years of age was fairly correlated with THg in maternal hair at delivery (rs=0.35; p<0.0001) and was strongly correlated with child's seafood consumption (rs=0.50, p<0.0001). No differences in maternal THg levels were found when comparing children with low or extremely low or high or extremely high scores vs others, considering separately full scale, verbal, and performance IQs. Children born from mothers with hair THg levels greater than or equal to 2000ng/g had full scale, verbal and performance IQs which were 4-5 points lower than children born from women with lower THg levels, but these differences were not statistically significant. Fresh fish intake of mothers in pregnancy was slightly positively associated with full scale and performance but not so with verbal IQs. Canned fish showed to be negatively associated with all the outcome variables. Unexpectedly, children born to mothers from one town showed IQ scores significantly lower than the other children; however, none of the many variables considered in these analyses could explain this result. The relatively low Hg levels found in the biological samples did not provide evidence of high and extensive Hg exposure in this population. Although THg levels in maternal and child's biological samples are correlated with fish consumption, the effects of THg and fish on neurological outcomes go in opposite directions. These results do not allow to develop recommendations regarding fish consumption in pregnancy but suggest that keeping THg hair levels<2000ng/g might be desirable.

Distractor objects affect fingers' angular distances but not fingers' shaping during grasping

The aim of the present study was to determine whether and how hand shaping was affected by the presence of a distractor object adjacent to the to-be-grasped object. Twenty subjects were requested to reach towards and grasp a 'convex' or a 'concave' object in the presence or absence of a distractor object either of the same or different shape than the target object. Flexion/extension at the metacarpal-phalangeal (MCP) and proximal interphalangeal joints of all digits, and abduction angle between digits were measured by resistive sensors embedded in a glove. The results indicate robust interference effects at the level of reach duration and the extent of fingers' abduction angles together with changes at the level of a single joint for the thumb. No distractor effects on individual fingers' joints except for the MCP of the middle and little fingers were found. These findings suggest that the presence of distractor object affects hand shaping in terms of fingers' abduction angles, but not at the level of 'shape dependent' fingers' angular excursions. Furthermore, they support the importance of the thumb for the guidance of selective reach-to-grasp movements. We discuss these results in the context of current theories proposed to explain the object selection processes underlying the control of hand action.