It has been suggested that survival in babies with trisomy 18 may be better than previously recognised, and that cardiac surgery may be justified. A population based study spanning seven years in one English health region is presented. The fetal prevalence at 18 weeks was 1 in 4274 and birth prevalence 1 in 8333 live births. Trisomy 18 was detected antenatally in 43% of cases, but almost 90% of...

The predicted incidence of liveborn monozygotic trisomy 18 twins is one per million births. The first case of liveborn monozygotic trisomy 18 twins was reported in 1989 and we report a second case in which striking phenotypic discordance existed. The probability of monozygotic trisomy 18 twinning and the mechanisms for phenotypic discordance in trisomic twins is discussed.

The natural history of trisomy 18 and trisomy 13 was investigated using data derived from parent questionnaires and medical records from 98 families with an index case of trisomy 18 and 32 families with an index case of trisomy 13. Data are presented on pregnancy, delivery, survival, medical complications, immunizations, growth, cause of death, cytogenetics, and recurrence risk. Half of the tri...

OBJECTIVE To examine the association between maternal serum levels of thyroid stimulating hormone (TSH) and free β-human chorionic gonadotrophin (free β-hCG) in trisomy 21, trisomy 18 and euploid pregnancies at 11-13 weeks and investigate the potential value of TSH in first-trimester screening for aneuploidies. METHODS Maternal serum TSH and free β-hCG levels at 11-13 weeks in 25 trisomy 21 a...

OBJECTIVES To assess thymic size expressed as the thymic-thoracic ratio (TT-ratio) in fetuses with trisomy 21, 18 or 13. METHODS The TT-ratio, the quotient of the anteroposterior thymic and the intrathoracic mediastinal diameter, was measured in 65 trisomic fetuses between 15 and 36 weeks' gestation, including 30 cases with trisomy 21, 19 with trisomy 18 and 16 with trisomy 13. In addition th...

OBJECTIVE To determine if in fetuses with aneuploidies the diameter of the fourth cerebral ventricle at 11-13 weeks' gestation is different from euploid fetuses. METHODS The fourth ventricle at 11-13 weeks' gestation was assessed in 62 cases of trisomy 21, 32 of trisomy 18, 10 of trisomy 13, and 12 of triploidy and compared to 410 normal euploid fetuses. Transvaginal sonography was carried ou...

OBJECTIVE To examine the possible association between aneuploidies and fetal lateral cerebral ventriculomegaly in the first trimester of pregnancy. METHODS Three-dimensional brain volumes were acquired by transvaginal ultrasound examination at 11-13 weeks' gestation in 410 euploid fetuses and 63 fetuses with trisomy 21, 34 with trisomy 18 and seven with trisomy 13. Lateral ventricles were ass...

Individuals with mosaic trisomy 18, only approximately 5% of all trisomy 18 cases, carry both a trisomy 18 and an euploid cell line. Their clinical findings are highly variable, from the absence of dysmorphic features to the complete trisomy 18 syndrome. A five-month-old daughter of a 38-year-old mother, with vomiting and feeding problems, was referred to our department. She was undernourished ...

This study examines 45 cases of trisomy 13 and 59 cases of trisomy 18 and reports an algorithm to identify pregnancies with a fetus affected by trisomy 13 or 18 by a combination of maternal age fetal nuchal translucency (NT) thickness, and maternal serum free beta-hCG and PAPP-A at 11-14 weeks of gestation. In this mixed trisomy group the median MoM NT was increased at 2.819, whilst the median ...

OBJECTIVE The aim of this study was to describe the communication ability of individuals with trisomy 18 and trisomy 13 syndromes. METHODS Parents reported on children's potential communication acts, words, spontaneous gesture, and augmentative and alternative communication (AAC) using a parent report inventory (n = 32; age range 3-35 years). Potential communicative acts are defined as behavi...