Seven cases of triploidy were encountered by the Prenatal Diagnosis Program at Dartmouth-Hitchcock Medical Center over an 8-year period through associated pregnancy complications. We describe the characteristic findings that facilitate prenatal diagnosis and management. Our experience includes fetuses with major central nervous system abnormalities (spina bifida aperta, holoprosencephaly) and anterior abdominal wall defects, which are detectable with routine prenatal diagnostic screening examinations (ultrasound and AFP). In addition, we stress the importance of recognizing obstetric complications and associated cystic placental changes, which are quite common among triploid conceptuses. Molar changes associated with triploidy have a more benign prognosis than that associated with diploid moles. Such molar changes may relate to the presence of a diploid paternal chromosome complement. The usefulness of cytofluorometric DNA determinations in helping to confirm a clinical suspicion of triploidy is emphasized. These cases are presented in an effort to facilitate prenatal recognition and management of this common cytogenetic condition and prevent unnecessary Caesarean section deliveries.

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As part of the diagnostic workup following an episode of fetal loss, it is generally recommended that fetal tissue be submitted for chromosome analysis and that the fetus be photographed and radiographed. Our recent clinical experience has suggested that, in those fetuses where size is compatible, xeroradiography may be superior to standard radiography. Xeroradiography utilizes principles similar to those in film radiology, with low-energy photon beams and relatively long exposure times. The physical characteristics of the beam and imaging system provide optimal soft tissue visualization. We have found this technique to be of use in studying a broad variety of abortuses with abnormalities. Examples of fetal abnormalities in which we have used this technique include acardia, neural tube defects, nuchal cystic hygroma, and arthrogryposis. In fetuses weighing 500-1,000 gm, the exposure settings are 25 MA, 1 second, 40 KVP. For larger fetuses the KVP should be increased by 1 or 2. This technique has not been useful for a complete body view of large fetuses due to the size limitations of the xeroradiographic cassette itself.

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Hyperamnonemia (amnonia nitrogen level >90 umol/L) during the first week of life was observed in 5 of 9 infants weighing slOOO grams at birth. Amnonia nitrogen levels ranged between 40 and 211 umol/L. Liver function tests were normal. None of these infants had received either oral or parenteral protein supplement. All 9 infants were receiving assisted ventilation. As part of