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.
1 It took the Decorah Eagles 37 days in 2009 and 2011, and 36 days in 2010. 2  35 to 37 days is a safe bet. 3  From pip to hatch: Pipping occurs when the baby eagle's egg tooth first breaks through the eggshell. 4  It can take as long as a day for the chick to fully hatch.