Duval is remembered for research involving placental development in mice and rats, and was the first to identify trophoblast invasion in rodents.

Normally this would not be possible due to genetic imprinting requiring genes inherited from the father for normal placental development.

It forms as a result of differentiation and fusion of the underlying cytotrophoblast cells, a process that continues throughout placental development.

Advanced maternal age is associated with adverse outcomes in the perinatal period, which may be caused by detrimental effects on decidual and placental development.

The effect is attributed to reduced placental development causing reduced fetal growth.

Hormonal effects appear implicated in the reduced placental development.

Its function is unknown; however, a similar protein in mouse plays an essential role in placental development.

It is those mammals that live more persecuted harried lives that have taken the possibilities of placental development to its ultimate.

Hydatidiform moles are abnormal conceptions with excessive placental development.