[Cancer and Pregnancy: the point of view of the obstetrician].

Onset of malignancy during pregnancy is distressing for the future parents and raises thorny problems for the oncologist and obstetric gynecologist. Many diagnostic and therapeutic approaches cannot be used. Some first-line reference treatments are known to cause fetal loss or severe birth defects, yet any delay in treatment may unacceptably worsen the maternal prognosis. In the absence of large randomized trials and cohort studies, it is difficult to know how best to manage these patients. An estimated one in ten thousand pregnancies are associated with malignancies, especially gynecologic tumors (cervix, breast, ovary), lymphomas, melanomas, brain tumors and leukemia. The obstetrician, in close collaboration with the oncologist, has a major role in choosing the most appropriate diagnostic and therapeutic strategy, and must keep the couple fully informed. Importantly, improvements in cancer cure rates and the development of conservative treatments mean that many of these young women can hope to start a new pregnancy after their treatment. The optimal interval between cure and conception must be carefully weighed up by a multidisciplinary team including oncologists and obstetric gynecologists. Chemotherapy, pelvic radiation therapy, and gynecologic surgery can impact not only on fertility but also on the course of a next pregnancy (increased risk of miscarriage and premature delivery, etc.). The obstetrician must take these risks into account.