The association of cancer and pregnancy is increasingly encountered nowadays in clinical practice. Due to the relative rarity of the situation, it lacks a systematized approach. Different systemic therapies are used in managing cancer with uncertainty regarding the potential hazards they could pose on the pregnancy and/or the fetus. We have performed a systematic review of literature to identify all reports addressing cancer patients who were exposed to any of the known systemic therapies during the course of the pregnancy. The results were discussed in two parts; part I addresses pregnant patients with solid tumors while part I for those with hematological malignancies. In part I, we identified different solid tumors diagnosed and treated during the course of pregnancy. Breast cancer was the most commonly treated followed by ovarian cancer. Other tumors were treated as well including lung cancer, cervical cancer, sarcoma and melanomas. It is important to acknowledge the intent of therapy (palliative vs. curative) and the patients has to be properly counseled to reach an informed decision. We aim to provide a more robust consensus on how to approach these cases and provide a higher degree of evidence to support the safety of applying certain management strategies over the other.