**Core Concept**
Cleft lip repair is a critical procedure in pediatric plastic surgery, requiring optimal timing for optimal outcomes. The best time for cleft lip repair is when the child is between 3-6 months of age, allowing for the best possible aesthetic and functional results.

**Why the Correct Answer is Right**
The American Cleft Palate-Craniofacial Association recommends repairing cleft lip between 3-6 months of age. This timing allows for the best possible alignment of the lip segments and the establishment of normal facial growth patterns. Additionally, early repair can help prevent future speech and feeding difficulties associated with cleft lip. The optimal timing is also influenced by the presence of other congenital anomalies and the overall health of the child.

**Why Each Wrong Option is Incorrect**
**Option A:** Repairing cleft lip at birth may not be ideal due to the child's small size and potential difficulties with anesthesia, as well as the risk of complications during the procedure.
**Option B:** Delaying cleft lip repair beyond 6 months of age may lead to difficulties with speech and feeding, as well as suboptimal aesthetic outcomes.
**Option C:** Repairing cleft lip at 1 year of age may be too late to prevent future speech and feeding difficulties, and may require additional surgeries to achieve optimal results.

**Clinical Pearl / High-Yield Fact**
The "rule of 10s" in cleft lip repair states that the best outcomes are achieved when the repair is performed between 3-6 months of age, when the child weighs 10 pounds, and when the length of the cleft is less than 10 mm.

**Correct Answer:** C.