The NICHD Study of Successive Small-for-gestational Age Births

The NICHD Study of Successive Small-for-gestational Age Births

– The Scandinavian SGA Studies

With a contract from the US National Institutes of Health (NIH), comprehensive data were collected towards the end of the 1980s from a sample of pregnant women at three Scandinavian universities (NTNU Trondheim, University of Bergen and Uppsala University). Selected children were followed up throughout and at the end of their first year of life and again when they were five years old. A subsample in Trondheim was followed up at age 10.

The main aim was to study how biological, behavioural and external factors influence fetal growth through the second and third trimester of pregnancy. Routine data on clinical and psychomotor development were collected through first year of life. At 13 months and 5 years of age comprehensive assessments were conducted. They focussed on potential physical, psychomotor and behavioural afflictions among children who were growth restricted or were lighter than expected at birth (= Small-for-gestational age/SGA)

Study characteristics:

1.   Pregnancy, Birth and 1st Year of Life (The SGA I Study)
The overall objectives were to study genetic, medical, social, and environmental factors that influence the physical and mental development of children from birth through the first year of life, related to fetal growth and size at birth.

Study population
Eligible for enrolment in the study were women of Caucasian (white) origin with one or two previous births, who spoke one of the Scandinavian languages, had a singleton pregnancy, and were registered by one of the study centres prior to the 20th gestational week. A total of 6,354 women were recruited to the study at their first antenatal visit. After screening for eligibility, there remained 5,722 women who fulfilled the entry criteria and gave the informed consent. Two categories of women were followed in detail throughout the rest of pregnancy: a. A 10% random sample (n=561) b. A sample of women at increased risk of giving birth to an SGA child based on previous pregnancy history (n=1384). Data were collected at four special study visits. Detailed maternal and newborn data were collected during and after birth, and until discharge from hospital.

2.   Follow-up at Five Years of Age (The SGA II Study)
The overall aims of the follow-up were to identify the outcomes of SGA infants at five years as a group. The objectives were to establish recommendations concerning: General health of pregnant women, Obstetric practice, Pediatric practice, Family intervention, and Health care programs for pregnant women and children.

Study population
The Five-year follow-up was a prospective study of growth and development during the first five years of life for two birth cohorts, one consisting of Small-for-Gestational Age (SGA) Births (n = 401), and the other of unselected non-SGA births (n = 512). The two cohorts were compared with regard to physical and mental development related to their intrauterine growth pattern and to genetic, medical, social, and environmental factors. The evaluation focused on neuromotor and mental functions, physical growth, sensory functions (hearing and sight), and behaviour. Parental and family characteristics were included in the database.

3.   Later follow up

-     At 10 years of age
Her kommer det mer informasjon om en substudie fra Trondheim basert på data som dr polit Helle W. Andersson samlet inn i samabeid med avdøde Johan Olav Undheim (1996). Data ble liggende ”untouched by the human brain” fram til 2008.

-     At 14-15 and 19-20 years of age
A study named Mental Health and Cerebral MRI in Children with Low Birth Weight (The VLBW/Premature study) organised and chaired by Professor Ann-Mari Brubakk and Professor Jon Skranes, NTNU have amongst others, followed up around 230 of the Scandinavian SGA study in Trondheim. Comprehensive clinical data at 15 and 20 years age have been collected in addition to information about physical development, behaviour, mental qualities, aptitudes, education, and psychiatric disorders and symptoms. A cerebral MRI scan has been conducted on both occasions (cf a separate detailed description from the Department of Laboratory Medicine, Women and Children’s Health, Faculty of Medicine). An interdependent and interdisciplinary cooperation has been established between the SGA and VLBW studies.

4.   What has the SGA study to offer?

Existing data
A vast amount of data are available from pregnancy and delivery, at birth and through the first to five years of life which can be analysed longitudinally and/or cross sectionally. In addition to clinical and other information regarding development, health, behviour, aptitudes and skills an overwhelming amount of serum samples are stored in a modernised biobank. Serum samples were collected longitudinally throughout pregnancy and at birth. They are available for separate, but not exclusive biochemical use, for instance repeat and validity analyses. Most preferably their use should be related to the analysis of other relevant and/or clinical data.

The SGA data- and biobank were subjected to a major overhaul and modernisation during the winter and spring of 2010. This will enhance the availability, retrieval and usability of all existing data and stored biomaterial.

Potential for further data collection
SGA data and serum are well suited for students who separately or in pairs wish to entrench themselves clinical and paraclinical subjects fag (obstetrics, neonatology, pediatrics, adolescent and medicine of young adults, pathology, and medical biochemistry). The data are also well suited for students with particular interests in epidemiology and biostatistics. During 2008-10 new informed consent was obtained from the mothers and their offspring (who are now aged 22-24 years) for continued participation and data collection. New clinical and sociodemographic data and samples of relevant biomaterial will enable further studies of any long term effects of slow or retarded fetal growth.

5.   References
Analyses of SGA study data have resulted in a vast body of scientific publications in peer reviewed journals and/or as masters or doctoral theses. A substantial number of undergraduate student theses have been published by the Faculty of Medicine, NTNU.

 

Gravid mage

Gravid mage

Contact:

Contact:

Professor Geir Jacobsen