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Evidence against oral contraceptives as a cause of neuraltube defects
Author(s) -
CUCKLE HOWARD S.,
WALD NICHOLAS J.
Publication year - 1982
Publication title -
bjog: an international journal of obstetrics and gynaecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.157
H-Index - 164
eISSN - 1471-0528
pISSN - 1470-0328
DOI - 10.1111/j.1471-0528.1982.tb03657.x
Subject(s) - medicine , relative risk , confidence interval , pregnancy , obstetrics , gynecology , family planning , population , research methodology , environmental health , genetics , biology
Summary. Information on oral contraceptive (OC) use, collected at the first antenatal visit, was abstracted from the medical notes in respect of 107 index pregnancies resulting in the delivery of an infant with a neural‐ tube defect (NTD) and 214 unaffected controls. The relative risk of having an NTD infant for women who had at any time used OCs was 0.82 (95% confidence interval 0.52,1.32) compared with that in women who had never used OCs. For women who stopped OC use less than 3 months before becoming pregnant or who continued in early pregnancy, the relative risk was 1.18 (95% confidence interval 0.70, 1.98) compared with women who had used OCs at any other time. An analysis restricted to those women who had at any time used OCs did not suggest an association between NTD risk and the interval between stopping OC use and becoming pregnant. None of our analyses therefore provided any evidence that OCs cause NTDs and if a risk exists it can only be small.