Livingston J E, Poland B J
Teratology. 1980 Apr;21(2):139-48. doi: 10.1002/tera.1420210202.
Fifty-three pairs of twins were obtained during examination of 1,939 spontaneously aborted complete embryos and fetuses. Therefore, the rate of twinning in pregnancies which spontaneously aborted was about 1 in 35. The spontaneous twin abortions consisted of 25 sets of twin embryos, 26 sets of twin fetuses, and two sets in which one was an embryo and one was a fetus. It was possible to determine the zygosity in 37 pairs. The ratio of monozygotic to dizygotic was 17.5:1. About 88% of the twin embryos and 21% of the twin fetuses were abnormal. These abnormality rates were similar to those observed in the overall study of the abortuses. The data on spontaneously aborted twins were compared with data on liveborn twins. The results suggest that twinning, particularly MZ twinning, occurs more frequently than has been thought, based on newborn data, and that embryonic and fetal mortality is much higher in twins than in singletons.
在对1939例自然流产的完整胚胎和胎儿进行检查期间，共获得了53对双胞胎。因此，自然流产妊娠中的双胎发生率约为三十五分之一。自然流产的双胞胎包括25组双胚胎、26组双胎儿以及两组，其中一组为胚胎，另一组为胎儿。在37对中可以确定其合子性。单合子与双合子的比例为17.5:1。约88%的双胚胎和21%的双胎儿存在异常。这些异常发生率与在流产总体研究中观察到的相似。将自然流产双胞胎的数据与活产双胞胎的数据进行了比较。结果表明，基于新生儿数据，双胎妊娠，尤其是单合子双胎妊娠的发生频率比之前认为的更高，并且双胞胎的胚胎和胎儿死亡率远高于单胎。
