Pregnancies resulting from fresh in vitro fertilization (IVF) cycles exposed to supraphysiologic estrogen levels have been associated with higher rates of low birth weight and small for gestational age babies. We identified GATA3, a transcription factor selectively expressed in the trophectoderm during the blastocyst stage of embryo development, in an upstream analysis of genes that were differentially methylated in chorionic villus samples between IVF and non-IVF infertility treatment pregnancies. In this study, we investigate the hypothesis that GATA3 is hormonally regulated and plays an important functional role in trophoblast migration, invasion, and placentation. We found that GATA3 expression was hormonally regulated by estradiol in HTR8/SVneo first trimester trophoblast cells; however, no change in expression was seen with progesterone treatment. Furthermore, GATA3 knockdown resulted in decreased HTR8/SVneo cell migration and invasion compared with controls. RNA sequencing of GATA3 knockdown cells demonstrated 96 differentially regulated genes compared with controls. Genes known to play an important role in cell-cell and cell-extracellular matrix interactions, cell invasion, and placentation were identified, including CTGF, CYR61, ADAMTS12, and TIMP3. Our results demonstrate estradiol down-regulates GATA3, and decreased GATA3 expression leads to impaired trophoblast cell migration and invasion, likely through regulation of downstream genes important in placentation. These results are consistent with clinical data suggesting that supraphysiologic estrogen levels seen in IVF pregnancies may play an important role in attenuated trophoblast migration, invasion, and impaired placentation. GATA3 appears to be an important regulator of placentation and may play a role in impaired outcomes associated with fresh IVF cycles.