Elevated levels of homocysteine in the blood appear to increase the risk of heart attack, stroke, peripheral vascular disease, and venous thrombo'embolism (blood clots in the veins). Homocysteine is believed to damage blood vessels in several ways.
I don't know for sure about how long Wrens usually spend on the nest at one sitting.. (Sorry couldn't resist the joke) However, the eggs usually hatch in 13-18 days, so if there were no hatchlings when that time elapsed, then you'd know for sure that she hadn't been behaving normally.
5. Wait until the eggs hatch. Incubation can take 28 to 35 days, and hatching can take as long as three days. 1  Keep the conditions of the nest clean throughout this entire period and continue turning the eggs each day during the entire process.