Haemoperitoneum due to ovarian rupture after oocyte retrieval procedure.

Transvaginal ultrasound-guided oocyte retrieval is the gold-standard technique for oocyte retrieval that has few associated procedural and post-procedural complications. Rarely, severe complications can occur including haemoperitoneum, for which the incidence reported in the literature is approximately 0.08-0.22%. In this report, we present the case of a nulliparous woman in her late 30s who presented to the hospital with severe abdominal pain following transvaginal ultrasound-guided oocyte retrieval and was found to have extensive haemoperitoneum attributed to ovarian rupture.

Periosteal Bone Formation Varies with Age in Periostin Null Mice.

Periostin, also known as osteoblast-specific factor 2, is a matricellular protein predominantly expressed at the periosteum of bone. During growth and development, periostin contributes to periosteal expansion by facilitating osteoblast differentiation and mineralization. Later in life, periosteal expansion provides an adaptive strategy to increase tissue strength without requiring substantial increase in bone mass. However, the function of periostin past skeletal maturity and during advanced aging is relatively unknown. The objective of this study was to examine the function of periostin in maintaining bone mass and tissue strength across different ages. In periostin null mice (Postn-/-), periosteal bone formation was significantly reduced in young (3 months) and adult mice (9 months). The lack of bone formation resulted in reduced bone mass and ultimate strength. Conversely, periosteal bone formation increased at advanced ages in 18-month-old Postn-/- mice. The increase in periosteal mineralization at advanced ages coincides with increased expression of vitronectin and osteopontin. Periosteal progenitors from Postn-/- mice displayed an increased capacity to mineralize when cultured on vitronectin, but not type-1 collagen. Altogether, these findings demonstrate the unique role of periostin in regulating periosteal bone formation at different ages and the potential for vitronectin to compensate in the absence of periostin.