Their most distinctive external feature is the presence of two suckers, one close to the mouth, and the other on the underside of the animal.The body surface of trematodes comprises a tough syncytial tegument, which helps protect against digestive enzymes in those species that inhabit the gut of larger animals. It is also the surface of gas exchange; there are no respiratory organs.The mouth is located at the forward end of the animal, and opens into a muscular, pumping pharynx. The pharynx connects, via a short oesophagus, to one or two blind-ending caeca, which occupy most of the length of the body. In some species, the caeca are themselves branched. As in other flatworms, there is no anus, and waste material must be egested through the mouth.Although the excretion of nitrogenous waste occurs mostly through the tegument, trematodes do possess an excretory system, which is instead mainly concerned with osmoregulation. This consists of two or more protonephridia, with those on each side of the body opening into a collecting duct. The two collecting ducts typically meet up at a single bladder, opening to the exterior through one or two pores near the posterior end of the animal.The brain consists of a pair of ganglia in the head region, from which two or three pairs of nerve cords run down the length of the body. The nerve cords running along the ventral surface are always the largest, while the dorsal cords are present only in the Aspidogastrea.
Infants from diabetic mothers usually have several blastogenic malformations. Diabetic embryopathy is therefore an etiological subgroup of defects of blastogenesis that present different monotopic and polytopic developmental defects. Abortion and perinatal deaths
Diabetic embryopathy may result in early or late spontaneous abortion and stillbirth. In maternal diabetes, 90% of pregnancy losses happen in the first trimester due to oxidative stress. Diabetic embryopathy abortions in the second-trimester are most likely due to severe birth defect, maternal metabolic derangement, placental insufficiency and fetal hypoxia due to membrane rupture. Pathogenesis
The development of birth defects associated with maternal hyperglycemia is multi-factorial. Environmental factors and genetic predisposition (paternal, maternal and offspring genome) are important in diabetic embryopathy. The diets of diabetic mothers impacts the rate at which malformations form in their offspring. Furthermore, there is evidence that resistance to certain malformations caused by diabetes is genetic. Epigenetics and its relationship with various environmental factors such as metabolism and diet play a significant role in teratogenesis. Hyperglycemia and associated teratogenic mediators influence DNA methylation, non-coding RNA expression, histone modifications and other epigenetic regulation mechanisms. Research is focused on exploring the impact of diabetic embryopathy on methylation signatures, which could potentially serve as a diagnostic biomarker for the condition. Prevention
Preconception
The probability of major birth defects in offspring of mothers with diabetes is 0.7-4.4% for glycohemoglobin levels <7%. For glycohemoglobin levels >10% the probability of major birth defects is 16.1-100% with an average of 26.6%.