**Current Understanding of Autophagy in Pregnancy**

#### **Akitoshi Nakashima 1, Sayaka Tsuda 1, Tae Kusabiraki 1, Aiko Aoki 1, Akemi Ushijima 1, Tomoko Shima 1, Shi-Bin Cheng 2, Surendra Sharma 2 and Shigeru Saito 1,\***


Received: 12 April 2019; Accepted: 10 May 2019; Published: 11 May 2019

**Abstract:** Autophagy is an evolutionarily conserved process in eukaryotes to maintain cellular homeostasis under environmental stress. Intracellular control is exerted to produce energy or maintain intracellular protein quality controls. Autophagy plays an important role in embryogenesis, implantation, and maintenance of pregnancy. This role includes supporting extravillous trophoblasts (EVTs) that invade the decidua (endometrium) until the first third of uterine myometrium and migrate along the lumina of spiral arterioles under hypoxic and low-nutrient conditions in early pregnancy. In addition, autophagy inhibition has been linked to poor placentation—a feature of preeclamptic placentas—in a placenta-specific autophagy knockout mouse model. Studies of autophagy in human placentas have revealed controversial results, especially with regard to preeclampsia and gestational diabetes mellitus (GDM). Without precise estimation of autophagy flux, wrong interpretation would lead to fixed tissues. This paper presents a review of the role of autophagy in pregnancy and elaborates on the interpretation of autophagy in human placental tissues.

**Keywords:** Atg7; autophagy; lysosomes; placenta; preeclampsia; protein aggregation; p62/SQSTM1
