A maternal serum alpha-fetoprotein (MsAFP) level greater than 2.5 MoM indicates which of the following risks?

A maternal serum alpha-fetoprotein (MsAFP) level greater than 2.5 multiples of the median (MoM) is associated with an increased risk for spina bifida and other neural tube defects. Alpha-fetoprotein is a protein produced by the fetal liver, and higher-than-normal levels in maternal serum can suggest the presence of conditions that lead to a defect in the fetus's neural tube closure, such as spina bifida.

When MsAFP levels are elevated, it typically indicates that there may be an abnormality, such as an open neural tube defect, allowing increased quantities of AFP to leak into the amniotic fluid and subsequently into the maternal circulation. Therefore, this significantly elevated level is clinically relevant when assessing risks for neural tube defects, with spina bifida being a primary concern.

In contrast, conditions like Down syndrome, Turner syndrome, and trisomy 13 are generally associated with decreased alpha-fetoprotein levels rather than increased levels. Therefore, focusing on the implications of elevated AFP levels specifically relates to the risk of spina bifida, making it the appropriate conclusion.