Cryopreserved placental biopsies maintain mitochondrial activity for high-resolution respirometry.

BACKGROUND: High-resolution respirometry (HRR) of human biopsies can provide useful metabolic, diagnostic, and mechanistic insights for clinical research and comparative medical studies. Fresh tissues analysis offers the potential best condition, the drawback being the need to use them shortly after dissection for mitochondrial respiratory experiments. The development of effective long-term storage protocols for biopsies that allow the assessment of key Electron Transport System (ETS) parameters at later stages is thus a major need. METHODS: We optimised a cryopreservation protocol that preserves mitochondrial membranes intactness, otherwise affected by direct tissue freezing. The protocol is based on a gradual freezing step from on-ice to liquid nitrogen and - 80 °C storage using a specific DMSO-based buffer. RESULTS: Placenta is a suitable tissue to design and test the effectiveness of long-term storage protocols being metabolically active foetal tissue with mitochondrial dysfunctions contributing to placental disease and gestational disorders. Here we designed and tested the effectiveness of the cryopreservation protocol using human placenta biopsies; we measured the ETS activity by HRR of placenta specimens comparing fresh, cryopreserved, and snap frozen conditions. CONCLUSIONS: By this protocol, Oxygen Consumption Rate (OCR) measurements of fresh and cryopreserved placental specimens are comparable whereas snap frozen procedure impairs mitochondrial activity.

Spontaneous hemoperitoneum in pregnancy: Italian prospective population-based cohort study.

INTRODUCTION: Spontaneous hemoperitoneum in pregnancy is defined as a sudden non-traumatic intraperitoneal bleeding in pregnancy and up to 42 days postpartum. In the present study we aim to estimate the incidence and investigate the risk factors, the management and the outcomes of spontaneous hemoperitoneum in pregnancy in order to improve its clinical identification and reduce avoidable maternal deaths. MATERIAL AND METHODS: This is a prospective population-based cohort study, set in maternity units from nine Italian regions covering 75% of the national births. The study population comprises all women admitted for spontaneous intraperitoneal hemorrhage during pregnancy and up to 42 days postpartum between November 2017 and March 2020. Incident cases were reported by trained clinicians through electronic data collection forms. Descriptive statistics were performed. The main outcome measures included incidence rate of spontaneous hemoperitoneum in pregnancy, association with potential risk factors, clinical management and maternal and perinatal outcomes. RESULTS: Twenty-nine cases met the adopted definition of spontaneous hemoperitoneum in pregnancy with an estimated incidence rate of 0.04 per 1000 births. An increased risk ratio (RR) of this condition was observed in pregnancies conceived by assisted reproductive technology (RR = 6.60, 95% CI 2.52-17.29), in the case of multiple pregnancies (RR = 6.57, 95% CI 1.99-21.69) and maternal age ≥35 years (RR 2.10, 95% CI 1.01-4.35). In 17/29 cases the bleeding site was intra-pelvic (23.5% in the posterior uterine wall and 35.2% in the left hemipelvis). Laparotomy represented the surgical treatment in 27 cases (93%), and most women underwent a cesarean delivery (92.6%). Median blood loss was 1900 mL, one hysterectomy was necessary, and two women died. Twenty-two preterm births were recorded. CONCLUSIONS: Spontaneous hemoperitoneum in pregnancy is a rare, life-threatening condition associated with high perinatal morbidity and mortality. Maternal age ≥35 years, multiple pregnancies and assisted reproductive technology were associated to a higher risk of the condition. Two women of 29 died and 70% of births occurred preterm.