With this newsletter we would like to express our sincere thanks to all participants and parents of the Bavarian Longitudinal Study and give a brief overview of the status of Phase 4 of the study!

What has happened so far:

The Bavarian Longitudinal Study (BLS) has its origin in the Munich Perinatal Study (Southern Bavaria) and the ARVOYLPPÖ Study (Southern Finland). For BLS, children born in a specific region of Southern Bavaria were enrolled between April 1985 and April 1986. At the beginning, these were 8421 children! Children and their parents were examined regularly over time. This happened at birth, and at 5, 20, and 56 months for Phase I of the study. The participating families from Southern Finland were not followed further afterwards. The BLS study families were examined at ages 6 + 8 years in Phase II and at 12/13 years in Phase III. Over the course of the study, the focus of the assessments shifted to the very preterm (< 32 weeks of gestation) and very low birthweight (< 1500 g) children and the control group of fullterm children.

Phase IV:

After more than 10 years, it has been possible to start another phase of the BLS. Funding was provided by the Federal Ministry of Education and Science to continue the study for another 6 years. Phase IV of the BLS began in summer 2009. Since then, more than 20 staff members have been hired. In addition, the assessments were planned, the necessary tests selected and some translated, examiners trained, and the assessment sites set up. An important aspect of the study is the recruitment of the participating families. Since the last assessments happened more than 10 years ago, it is a major challenge to locate all former study participants. For Phase IV of the study, there are approximately 770 families we wish to contact.

Who is who:

The study staff are spread across several study sites.

The study office is located at the University Children’s Hospital in Bonn, in the Department of Preterm and Neonatal Medicine, led by Prof. Dr. Dr. Peter Bartmann. From there, the participants and their families are recruited. The three staff members there contact the participants and coordinate the assessments. In addition, the study office coordinates and conducts the parent interviews and organises meetings and telephone conferences of the study staff.

The psychological and contentrelated leadership lies with Prof. Dr. Dieter Wolke at the Department of Psychology at the University of Warwick (England). Prof. Wolke has been involved in the study since the beginning. He and his team are responsible for the development and supervision of participant interviews and the analysis of data from Phases I–III.

The office for the examiners who conduct the participant interviews is located in Augsburg. The examiners travel to the assessment locations Augsburg, Munich, Regensburg, or Deggendorf.

The functional MRI examinations take place at the Radiology Clinic of the University of Bonn or at the Klinikum Rechts der Isar of the Technical University of Munich.

In addition, the Coordination Centre for Clinical Studies in Düsseldorf is responsible for quality control of the study.

Since summer 2009, the entire study team has already met five times for meetings in Bonn and Munich. There are also regular telephone conferences with the entire study team. The next meeting is planned in Warwick (England) in April 2012.

Assessments:

During Phase 4 of the BLS, three assessments take place:

The first assessment is the participant interview. For this, participants are contacted by the study office, and an appointment is arranged in one of the four assessment locations: Augsburg, Munich, Regensburg, or Deggendorf. The interview takes place in the morning and afternoon, and participants are asked, for example, about their personal life satisfaction and their social, occupational, and health status. Since many participants are in training or employed, the study office offers various forms of support, such as contacting employers to request leave for the assessment day. The participant interviews have been taking place since September 2010.

After completing the interview, participants are invited to an MRI examination provided they are happy to take part and there are no medical reasons not to. This examination takes place in Bonn or Munich. In Bonn, participants arrive the day before and are accommodated near the examination site for one night. The MRI examination, including the briefing, explanation, and scan, takes about three hours. The MRI examinations have been taking place since December 2010.

The parents of the participants are also included in the study again and asked to participate in a parent interview. This takes place by telephone and by means of questionnaires sent by post. The telephone interview lasts about 20–30 minutes. The parent interviews have been taking place since July 2011.

Who is participating again:

So far we have succeeded in locating 85% of the study families and winning back 66% for the study! Due to the long break in contact since the last assessments in Phase III, it is often very difficult to obtain the current addresses of the families. For the success of the study, it is of the greatest value to find as many study families as possible again. Each participant who cannot be located is an irreplaceable loss for the study, as we cannot recruit new participants and rely on the cooperation of OUR participating families! Only from these families do we have data from the earlier phases and can make comparisons with data from this phase.

At the end of November 2011, 241 participant interviews, 66 MRI examinations, and 113 parent interviews have taken place!

We thank all participants and parents for their commitment and the trust they have placed in us!

Financial matters:

In addition to a compensation of €30, all participants are reimbursed for their travel and, if applicable, accommodation by the study office. During the MRI examination in Bonn, an advance payment in cash is also made on site to cover part of the travel costs in advance. In addition, all participants receive a small gift.

What has been found so far:

As part of the Bavarian Longitudinal Study, we were able to collect data thanks to the willingness and cooperation of parents and children that have led to new findings. Some of these findings help improve the care of all children and their parents. Others have particular significance for pretermborn children.
Below we present a few examples of the findings:

I. Crying, sleeping, and feeding in infancy

In the first year of life, an infant should learn to regulate crying, fall asleep independently in the evening and sleep through the night, and in the second half of the year manage the transition from milk to solid food. We were able to show that one in four infants examined has difficulties with crying, sleeping, or feeding, and some (up to 10%) show multiple problems. Those with multiple problems are often referred to as children with regulatory problems. These can be a major burden for affected parents.

In approximately 8% of children, the regulatory problems persisted throughout the preschool period, and it was found that these children more often had problems with social behaviour and still slept or ate worse at five years of age.

The study led to an overall consideration of the influence of early regulatory problems on later behaviour, i.e. we collected all studies (over 20) on the subject and analysed them across studies (metaanalysis). The result was as follows: if a child already has a regulatory disorder in the first year, the risk of a behavioural regulation disorder in the preschool years is twice as high as in children who did not have a regulatory disorder in the first year. These results help ensure that paediatricians cannot simply reassure affected parents that children will “grow out of it” – because some parents and their infants need appropriate support.

II. Pregnancy and smoking

We examined the effects of maternal cigarette consumption before and during pregnancy on the cognitive development of their children. A recent study from Finland reported that heavy smoking before pregnancy negatively affected children’s cognitive performance at age 4, even if the mother had stopped smoking during pregnancy. However, our data show that there is a big difference between mothers who stopped smoking at the beginning of pregnancy and those who smoked throughout pregnancy: continuous smoking during pregnancy led to poorer verbal abilities in children at age 4. However, there were no differences between children whose mothers had never smoked and those whose mothers had stopped smoking before or immediately at the beginning of pregnancy. This shows that it is very important for the cognitive development of the child to stop smoking before or at the beginning of pregnancy.

III. Cognitive performance, attention, and school success

Former pretermborn children have an increased risk of problems in cognitive performance, social behaviour, and in their attention regulation compared to fullterm children. These abilities are very important for learning and influence later school success. The degree of risk for school success depends on gestational age: for example, only a small proportion of moderately pretermborn children (born in weeks 32–36) develop school problems, while each week lost significantly increases the developmental risk for very (< 32 weeks) or extremely (< 26 weeks) pretermborn children. Many parents and teachers expect former pretermborn children to catch up with their peers by school entry. The majority of pretermborn children do catch up, while those with persistent severe developmental problems in the second year of life more often have longterm cognitive and school problems.

Proportion of children who have problems in their academic performance, divided by gestational age in weeks

(data from various studies)

We have shown that children who were born too early or with a very low birthweight and small have increased attention problems in primary school age. Particularly interesting is that boys overall show attention problems more often, but girls are at higher risk of developing attention problems due to preterm birth. Very pretermborn children have a 2–3fold increased risk of being diagnosed with attention deficit disorder (ADD) compared to fulltermborn children but are not more often hyperactive or impulsive. A combination of cognitive deficits and attention problems during primary school age is associated with school problems in adolescence. We are therefore currently working on learning more about the relationships between early brain development, cognitive abilities, and attention to better support the academic success of children and adolescents in the future.

IV. Compensation of risk due to preterm birth

For the development of good interventions for former pretermborn children, we must know and consider their special needs. One important question is the extent to which environmental conditions can have a compensatory effect for pretermborn children. Family factors such as the quality of parentchild interactions and a cognitively stimulating environment can positively influence a child's developmental prognosis. Based on data from the Bavarian Longitudinal Study, we were able to show that some of the milder problems after preterm birth can also be mitigated by parents: parents who provide their children with rich learning opportunities during kindergarten and primary school age actively promote longterm school success, for example by teaching them numbers and letters or reading to them often. Some studies have found that pretermborn children behave more passively in social interactions because they may be overwhelmed by the cognitive complexity of the situation. Our results show that parents of children with cognitive problems intuitively behave more controlling in situations that are mentally demanding for the child (e.g. homework). In this way, they reduce cognitive demands, direct the children’s attention, and help them solve tasks. Thus, parents with a combination of high sensitivity and high verbal control can optimally promote the persistence of children with cognitive problems in primary school age.