Third-trimester fetal death in triplet pregnancies. During the last decade, 89 sets of triplets were born in Denmark with a gestational age of more than 25 completed weeks. Fifteen pregnancies (16.9%) were complicated by fetal death in the third trimester, with a total of 17 intrauterine deaths. Six neonatal deaths occurred, leaving 22 survivors among these 15 patients. Four triplet gestations were diagnosed as twins until delivery. Eight women conceived spontaneously, two gestations followed assisted fertilization and embryo transfer, and five women had had various forms of ovulation stimulation. The mean maternal age was 27.8 years (range 17-38). Seven women were parous and eight wer nulliparous. Maternal complications included hydramnios (three), preeclampsia/hypertension (three), and anemia (nine). All women delivered preterm. Of the 11 gestations diagnosed as triplets, fetal death was diagnosed at 32.2 +/- 2.9 weeks (mean +/- SD) and delivery occurred at 32.6 +/- 3.0 weeks. Nine of 11 women had cesarean deliveries. Continuation of pregnancy after fetal death could be considered in only three subjects. In eight women, obstetric reasons required immediate delivery. Fetal death was associated with monochorionic or dichorionic placentation, and growth retardation was a frequent complication before fetal death. Anencephaly of one fetus, umbilical cord problems in two, and severe hydrops in two were the only obvious causes of fetal death. Fetal death should not be the sole indication for delivery. In cases with severe prematurity and a stable intrauterine situation, frequent assessments of fetal well-being are recommended, with prompt delivery when indicated. 