ESPE Abstracts

Background: Low birth weight and unfavourable intrauterine conditions are associated with long-term effects on life.

Objective and hypotheses: In a longitudinal study, we followed genetically identical twins with intra-twin birth-weight (bw) differences due to twin–twin transfusion syndrome from birth until after puberty. We propose that differences in birth weight lead to differences in hormone levels with effects on personality and cognitive function.

Method: 43 pairs of monozygotic twins with intra-twin bw-differences were seen at birth, 2.8 and 15.0 years, 28 of these pairs were also seen at 17.6 years. Auxiological data were collected at all occasions; we differentiated between donators (lower birth weight) and acceptors (higher birth weight). At 15 years, fasting blood was drawn to measure levels of gonadotropins, steroids, adrenal and thyroid hormones. Additionally, two psychological questionnaires were issued: the Strength and Difficulties Questionnaire (SDQ-self and -parent) and the Kidscreen-52 (Health Related Quality of Life). At 17.6 years an IQ-Test (WAIS-IV, Wechsler Adult Intelligence Scale) was administered.

Results: Endocrine parameters did not differ significantly in-between twin-pairs. Preliminary results of 26 subjects (13 pairs) showed no significant differences for cognitive function between donators and acceptors. FSH-levels at 15 years of age were positively correlated with perception-linked logical thinking at 17.6 years, while IGF-1 was negatively correlated with speech comprehension and working memory. Testosterone concentration was negatively correlated with emotional problems and positively with quality of self-perception, while Estradiol conc. was positively connected to prosocial behaviour. While T4-levels were also positively correlated with prosocial behaviour, they were negatively associated with parent-observed hyperactivity. TSH on the other hand was positively correlated to perceived autonomy and relationships to family members.

Conclusion: Endocrine parameters are closely linked to differences in personality and quality of life in adolescent monozygotic twins. Preliminary results also suggest an impact on cognitive function. If these differences can actually be associated with birth weight differences has yet to be determined, further analyses will be performed on the presented sample.