Maternal malignancy during pregnancy is estimated to occur in 1 out of 1000 pregnancies. Controversy exists regarding the effect of pregnancy on cancer prognosis. Gestational hormones and pregnancy-related growth factors may induce a more aggressive behavior in malignant cells. However, metastasis to the products of conception is rare. In the current study investigators wish to analyze the effect of placental explants on cancer cells (cervical, ovarian, thyroid, melanoma, lymphoma, leukemia and breast)phenotype (cell death, proliferation, migration , invasion), signaling pathway, mRNA, miRNA and protein expression.

In the Oncogenetic laboratory cancer cells will be exposed to first trimester human placental explants or to serum collected from pregnant women. As a control cancer cells will be cultured alone or in the presence of sera collected from young (18-45) non pregnant women.

Placentae, 6-9 weeks gestational age, will be retrieved from terminated normal pregnancies. The placenta will be taken after pregnancy termination, thus, no harm will be caused for the women.

The sera will be collected from the women by an authorized physician. It will be taken from: 1. the vein of the non pregnant women and volunteered pregnant women. 2. from the same branula that will be introduced into the pregnant women as a routine during pregnancy termination procedure.

Following culture investigators will analyze the cancer cells phenotype (cell death, proliferation, migration, and invasion), signaling pathway, mRNA, miRNA and protein expression.

Sera will be collected from 50 pregnant women and 50 non pregnant women. Placentae will be collected from 50 pregnant women.

Inclusion Criteria:

• Healthy women
• Age 18-45.
• Pregnant (6-9 weeks) and non pregnant women.

Exclusion Criteria:

• Placentae that were destroyed during pregnancy termination.

Healthy women Age 18-45. Pregnant (6-9 weeks) and non pregnant women.