Number of life births associated with melanoma risk

Women giving birth one or more times are in increased risk of developing malign tumours. So concludes a case-control study of 318 women with malign melanomas, compared with 395 frequency-matched control participants. Women with multiple childbirths (3 or more births) showed a 3-fold higher risk than women not having experienced any childbirth (odds-ratio).

Women with nevi growing in numbers and size during pregnancy were in particular risk of developing melanomas. However, the study found no association between oral contraceptive use or hormone replacement therapy with melanoma risk. 

 
Lea CS, Holly EA, et al. Reproductive risk factors for cutaneous melanoma in women: a case-control study. Am J Epidemiol. 2007;165:505-513.