Best results are obtained when sacrococcygeal teratoma is operated:

Ans: a (Immediately after birth) Ref: Bailey & love, 24th ed, p. 1248SACROCOCCYGEAL TERATOMAAlthough rare, it is among the most common of the large tumours seen during the 1st three months of life. The frequency of the precoccygeal region for the development of teratoma is explained by the fact that this area is the site of primitive knot, a group of totipotent cells that retain their totipotentiality longer than any others.* Females are more affected.* Arises b/w sacrum and rectum and firmly attached to coccyx.* MRI is very useful in making the diagnosis and extent of tumour.* Large tumours are prone to become malignant usually at 10 months of age.TreatmentRemoval soon after birth, delay is liable to result in fatal ulceration, infection, rectal or urinary obstruction or malignant change.