EFFECTS OF AGE, CIGARETTE-SMOKING, AND OTHER FACTORS ON FERTILITY - FINDINGS IN A LARGE PROSPECTIVE-STUDY
EFFECTS OF AGE, CIGARETTE-SMOKING, AND OTHER FACTORS ON FERTILITY - FINDINGS IN A LARGE PROSPECTIVE-STUDY
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DOI:
10.1136/bmj.290.6483.1697
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发表时间:
1985-01-01
影响因子:
105.7
通讯作者:
YEATES, D
中科院分区:
文献类型:
--
作者:
HOWE, G;WESTHOFF, C;YEATES, D
Of 17,032 women taking part in the Oxford Family Planning Association [UK] contraceptive study, 4104 stopped using a birth control method to plan a pregnancy on a total of 6199 occasions. The influence of various factors on fertility in these women was assessed by measuring the time taken to give birth to a child. An appreciable inverse relation was observed between age at stopping contraception and fertility both in nulliparous and parous women, but the effect was much greater in the nulliparous women. The most important finding was a consistent and highly significant trend of decreasing fertility with increasing numbers of cigarettes smoked per day; it was estimated that 5 yr after stopping contraception 10.7% of smokers smoking more than 20 cigarettes a day, but only 5.4% of non-smokers, remained undelivered. Some relation was found between fertility and social class, age at marriage and a history of gynecological disease, but weight, height and Quetelet''s index were without noticeable effect.