Final answer:
Pregnant women with type 1 diabetes mellitus have an increased risk of preeclampsia, diabetic ketoacidosis, fetal growth restriction, and other complications due to high blood glucose concentrations damaging small blood vessels.
Step-by-step explanation:
The risk for various pregnancy complications is increased in clients with type 1 diabetes mellitus. One key issue is the development of diabetic ketoacidosis (DKA), which is more likely during the third trimester when the demand for glucose doubles. The high blood glucose concentrations characteristic of poorly controlled diabetes can damage small blood vessels, leading to complications such as preeclampsia, fetal growth restriction, preterm birth, and stillbirth. It's critical for pregnant women with type 1 diabetes to maintain tight glucose control to minimize these risks.