Understanding Enlarged Kidneys in Pregnancy: What You Need to Know

Question
i'm a 23 year old woman that is 22 weeks pregnate. i recently went on Dec. 23, 2004 for my 20 week ultrasound. well i got a call the other day from my midwife saying that the babies kidneys are larger then normal and that i should not worry.. She told me that she has scheduled another ultra sound for the 2nd of feb. but what could cause the kidneys to be enlarged? and should i really be worried?

Answer
During pregnancy, enlarged kidneys can be normally seen due to dilatation of the collecting ducts or hydronephrosis of the ureters, causing some blockage in the fetal kidneys. If there is any blockage, there would be less amniotic fluid seen on ultrasound. Sometimes cysts can form in the fetal kidney. These usually are not a problem and the enlarged kidneys do not appear enlarged in subsequent sonogram examinations. It could also be an artifact or a subjective error in measurement by the sonographer. Be patient and wait to see what the next sonogram shows. Then discuss it in detail with the obstetrician.