aplacental
/ˌæpˈlæsɛntəl/Definitions
1. adjective
Not having a placenta; especially, in embryology, relating to an embryo that develops without a placenta.
“The unusual aplacental development in the fetus is a rare occurrence in the field of obstetrics.”
2. adjective
Lacking a placenta, especially in the development of an embryo.
“Aplacental development is a complex and poorly understood process in the field of embryology.”