Background Fetal volvulus is a rare, yet life-threatening condition that requires skilful diagnosis and management. Volvulus occurs when bowel loops become twisted and the twisting of the mesenteric artery leads to congestion, impaired venous return, and bowel necrosis. Case Description We present a case of fetal ileal volvulus suspected on third trimester ultrasound, complicated by premature labour, small bowel necrosis, and meconium peritonitis. Progressive dilatation and decreased peristalsis of echogenic bowel were noted in the early part of the third trimester. Daily surveillance ultrasound was performed and spontaneous labour occurred at 32 weeks' gestation. A proactive postnatal approach guided by prenatal sonographic findings allowed prompt treatment and an urgent laparotomy was performed for an ileal volvulus with necrosis and meconium peritonitis. A segment of small bowel volvulus was resected and an end-to-end anastomosis was performed with uneventful recovery. Discussion Clinically signs of fetal midgut volvulus are not pathognomonic, such as intestinal dilatation, abdominal mass, ascites, peritoneal calcifications, or polyhydramnios; thus, the diagnosis is often challenging. Complications reported in the literature include perforation and haemorrhagic ascites, which may lead to anaemia, hypovolemia, heart failure, and fetal demise. Conclusion This case highlights the importance of assessing the fetal bowel as a part of routine third trimester ultrasound. The case describes the complexity of diagnosis in the fetus, important considerations along with multidisciplinary team approach to management.
We determined the contribution of calcite to the total particle-size spectrum of Lake Michigan seston during different seasons in 1978–83 and 1985, employing a novel Coulter counter method, to examine the intensity and ecological effects of calcite whitings that result from autogenic precipitation of calcite. The whitings were most intense during September, when 12–56% of the total particle volume was calcite. Overall, food web dynamics were more controlling of than controlled by whitings. Year-to-year variation in calcite concentration was probably caused by predation-controlled variation in primary production, which drives calcite precipitation through CO2 uptake. Feeding rate of cladocerans in Lake Michigan is slightly reduced (16%) by calcite, but that of copepods is not. Light extinction is only slightly increased. Coprecipitation and sinking of P with calcite is probably a minor factor in regulating P concentration in the epilimnion of Lake Michigan. Removal of nutrients is enhanced by increased sinking rates caused by inclusion of calcite in fecal pellets and matter. Although all of the effects of calcite on plankton dynamics appear to be subtle in Lake Michigan, large effects can be expected for lakes of greater calcium hardness and eutrophy.
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