The risk of malformation in women who take oral contraceptives (colloquially known as the pill) and become pregnant despite taking them or immediately after stopping them is not increased. This was shown by an evaluation of 880,694 women who had a child in Denmark between 1997 and 2011. First group: 74,542 women (8%) had stopped oral contraception less than three months before becoming pregnant.Second group: 11,182 women (1%) became pregnant despite taking oral contraceptives. Result: 1,856 malformations occurred in the first group (prevalence (disease incidence): 24.9 per 1,000 births).In the second group, 277 malformations were diagnosed (prevalence: 24.8 per 1,000 births),
Mothers who had never taken the “pill”: prevalence (disease frequency) for malformations: 25.1 per 1,000 children.Women who had taken the “pill” but had stopped more than three months before pregnancy: prevalence for malformations: 25.0 per 1,000 children.
The authors also conducted analyses on individual specific malformations. They looked at malformations that had been associated with oral contraceptive use in previous studies. These include gastroschisis (also known as abdominal cleft; abdominal wall defect usually on the right side of the navel), hypoplastic left heart syndrome (HLHS; several associated malformations of the heart and the connected aorta) and limb defects. They were unable to confirm an increased rate of malformation for any of these malformations.
