Record R G, Armstrong E, Lancashire R J
J Epidemiol Community Health (1978). 1978 Sep;32(3):183-9. doi: 10.1136/jech.32.3.183.
Data on all births to Birmingham residents during a ten-year period were used to compare the reproductive history of mothers immediately before and after a twin maternity with that of mothers of similar age and parity before and after a single birth. It was found that mothers of twins were less likely than mothers of singletons to have a subsequent birth if both twins survived, but if only one survived there was little difference between the two groups. If both twins died, however, the likelihood of a later birth was increased. The interval before the next birth was longer than expected when both twins survived and much shorter when both died. The sex of the twins appeared to have little influence on subsequent reproduction, in spite of the fact that for singleton-containing fraternities a further pregnancy was more likely if the first two children were of the same sex than if they were of opposite sexes. The mean interval preceding a twin maternity was almost the same as that preceding a single birth when both twins survived, but it was shorter when one twin died (being similar to that preceding the birth of a singleton who died) and it was much shorter when both twins died.
研究使用了伯明翰居民在十年期间的所有出生数据，比较双胞胎产妇在双胎分娩前后与单胎分娩的相似年龄和胎次的产妇在单胎分娩前后的生育史。研究发现，如果双胞胎都存活，双胞胎母亲随后生育的可能性低于单胎母亲，但如果只有一个存活，两组之间差异不大。然而，如果双胞胎都死亡，随后生育的可能性会增加。当双胞胎都存活时，下次分娩前的间隔比预期长，而当双胞胎都死亡时则短得多。双胞胎的性别似乎对随后的生育影响不大，尽管事实上对于包含单胎的异卵双胞胎来说，如果头两个孩子性别相同，再次怀孕的可能性比性别相反时更高。当双胞胎都存活时，双胎分娩前的平均间隔与单胎分娩前几乎相同，但当一个双胞胎死亡时间隔较短（与死亡单胎分娩前的间隔相似），当双胞胎都死亡时间隔则短得多。
