Twin-twin transfusion syndrome--possible roles for Doppler ultrasound and amniocentesis.

A 29-year-old woman was referred for suspicion of twin-twin transfusion syndrome (TTTS). Several ultrasonographic and neonatal criteria of TTTS were encountered in this twin pregnancy. The peculiar observations in this case were, firstly, the demonstration of superficial anastomosis by Doppler ultrasound and, secondly, that one single therapeutic amniocentesis could have been sufficient to partially correct the progression of the syndrome, as after amniocentesis it was no longer possible to demonstrate the vascular communication. This observation suggests that superficial anastomoses could also have a role in the genesis of TTTS. Their effect could be monitored by Doppler ultrasound and could be more easily corrected by therapeutic amniocentesis.

Ultrasonic demonstration of the amnion.

The amnion can be visualized in most pregnancies before the 12th week. It appears as a thin membrane separating the amniotic cavity, which contains the fetus, from the extra-embryonic coelom and the secondary yolk sac. In a prospective study of 32 women in the first 12 weeks of pregnancy, the amnion was demonstrated ultrasonographically in 27 (84 per cent). The embryonic origin of the amnion and possible difficulties in its demonstration by ultrasound are described.

Ultrasonic evaluation of fetal limb growth: part II.

The length of the ulna, radius, tibia, and fibula was measured in 220 normal fetuses. Computerized curve fitting provided normal values of bone length for age and biparietal diameter. Ratios of the length of the different bones are presented. Possible applications of these measurements include: in utero diagnosis of fetal dwarfism, limb malformations, microcephaly, determination of gestational age, archeological dating of fetuses, and forensic applications.