Synchronous uterine and conceptus development in pigs

Among all mammals, the pig exhibits the most severe naturally occurring IUGR (15-25%) due to the increased fetal crowding during gestation and limited uterine capacity. Uterine capacity is the result of the combined effects of uterine, placental and fetal functions established as early as Days 12 to 30 of gestation and continuing to Days 30 to 40 of gestation, the critical period of placentation. Porcine conceptuses (embryo/fetus and its extraembryonic membranes) undergo rapid transitions from spherical to tubular to filamentous forms and implant to the uterus between Days 13 and 20 of gestation. Notably, 30% of porcine conceptuses arrest during the same time frame, increasing to 40% by Day 30 of gestation. Our long-term goal is to understand the fundamental roles of conceptus- and uterine-secreted factors that govern synchronous uterine and conceptus development required for implantation, the establishment of pregnancy, and placental development required for fetal growth and survival.  We aim to develop new strategies to optimize placental and fetal growth that will improve the overall health and survivability of piglets before and after birth to reduce neonatal death losses.

Age-associated uterine adaptability to pregnancy

Childbirth at advanced maternal age (i.e., ≥35 years old) is associated with an increased risk of adverse pregnancy outcomes such as preterm birth, preeclampsia and intrauterine growth restriction. A significant portion of reproductive aging research has focused on ovarian dysfunction, gamete quality and thus karyotypic abnormalities within the blastocyst; however, recent research studies have identified a prominent alteration in the uterine environment as the prevalent cause of age-related reproductive decline, e.g., severe placentation defects and abnormal embryonic development. We have identified that aging compromised the ability of uterus to undergo decidualization instead of implantation. Our long-term goal is to investigate the molecular mechanisms that underlie the age-associated uterine adaptability to pregnancy.