A woman in her 20s has experienced a miscarriage at 10 weeks' gestation and asks the nurse at the hospital what went wrong. she is concerned that she did something that caused her to lose her baby. the nurse can reassure the woman by explaining that the most common cause of spontaneous miscarriage in the first trimester is related to which factor?

Spontaneous miscarriage in the first trimester is related to Chromosomal defects in the fetus. An estimated 15 to 20 percent of known pregnancies end in miscarriage, the loss of a pregnancy before the 20th week. Upto 70 percent of first-trimester miscarriages, and 20 percent of second-trimester miscarriages, are caused by chromosomal anomalies/abnormalities in the fertilized egg. Most often, it means that the egg or sperm had wrong number of chromosomes, and consequently the fertilized egg can't develop normally.