Differences and similarities in the intra-uterine behaviour of monozygotic and dizygotic twins.

Diagnostic advances have made it possible to use ultrasonograph to assess placentation and therefore zygosity in utero in the case of monochorionic-monozygotic twins. Foetal behaviour of 15 monozygotic and 15 unlike-sexed dizygotic twin pairs was studied serially with ultrasounds from 10 to 22 weeks gestational age. Each twin, regardless of its zygosity, showed individualised behavioural styles.

Patterns of evoked behaviour in twin pregnancies during the first 22 weeks of gestation.

The objective of this work was to investigate the emergence of intrapair stimulation between twin fetuses and the presence of possible changes in types and percentage of evoked patterns with advancing gestational age. The existence of intrapair stimulation would indicate the functioning of fetal tactile and proprioceptive sensibility. This was studied from video recordings of 30 min ultrasonographic observations of 8 twin pregnancies at 8, 9 and 10 weeks gestational age, of 20 twin pregnancies at 11, 12 and 13 weeks and of 20 twin pregnancies studied with 60 min observations at 15-16, 18-19 and 21-22 weeks.

Infant observation from before birth.

This paper describes research on the extension of infant observation to pre-natal life with the aid of ultrasounds. First there is some mention of the technique of ultrasounds and of the advances in our knowledge of pre-natal life brought about by it. A description of the research follows: 5-6 ultrasonographic observations lasting about one hour each starting from the 14th-18th week of pregnancy are carried out at monthly intervals till the end of pregnancy.