Murphy M, Seagroatt V
Department of Public Health and Primary Care, Radcliffe Infirmary, Oxford.
Arch Dis Child. 1992 Feb;67(2):189-91. doi: 10.1136/adc.67.2.189.
The trends in British twin and higher multiple birth rates inside and outside marriage from 1938 to 1989 were reviewed for evidence of the probable impact of the use of ovulatory stimulants. After adjustment for maternal age monozygotic twin rates within marriage rose to a significant excess (of 12%) over those outside during the last two decades; a similar increase of higher multiple births within marriage to a significant excess (of 50%) over those outside was also seen for 1980-9. The dizygotic twin rate within marriage exceeded that outside in 1989 for only the second time in 50 years, as the difference in rates narrowed in the last decade. It is concluded that ovulation induction and techniques of assisted conception are apparently more available to the married, with a stronger effect on higher multiple birth rates than on dizygotic twin rates. Monozygotic twin trends support the suggestion that part of the infertility treatment regimen also promotes zygote splitting.
回顾了1938年至1989年英国婚内和婚外双胞胎及多胞胎出生率的趋势，以寻找使用促排卵药物可能产生影响的证据。在对产妇年龄进行调整后，婚内单卵双胞胎率在过去二十年中比婚外单卵双胞胎率显著高出（12%）；1980 - 1989年期间，婚内多胞胎出生率也出现了类似的增长，比婚外多胞胎出生率显著高出（50%）。婚内异卵双胞胎率在1989年超过婚外异卵双胞胎率，这是50年来的第二次，因为在过去十年中两者的差距缩小了。得出的结论是，诱导排卵和辅助受孕技术显然在已婚人群中更易获得，对多胞胎出生率的影响比对异卵双胞胎率的影响更大。单卵双胞胎的趋势支持了这样一种观点，即部分不孕治疗方案也会促进受精卵分裂。
