Hello. I will explain your ultrasound report- - The letter Y mentioned in the report is not a part of standard reporting format, and you must talk to your doctor about it. It may mean that the structures without the Y, were not well visualized by the sonographer. - There is a single fetus of 17 weeks and 5 days (17w5d), by ultrasound dates. - it is in breech position- butt/feet down near the cervix, head up - baby weight is 208 gm +/- 30- - persistent focal contraction means there was a uterine contraction during the scan. usually nothing to worry. - Placenta:lower edge is 3.5 cm from the (internal os) cervix. - Fetal heart rate is 151/beats per min: normal - normal fluid around baby. - There is mild dilatation of renal pelvis both sides (fluid filled in part of kidney) In my opinion the size mentioned is borderline/minimal, and I would do a thorough study (Anomaly scan) in a 3 weeks time, for any other gross abnormalities to suggest a chromosomal defect. In the majority of cases, it is physiological and resolves spontateously. However, if the dilatation persists/increases it may signal a urinary tract abnormality. Do not worry about it. Write in if you have any more doubts. Take care.