(Updates with details) MEXICO CITY, April 30 (Reuters) - Mexico’s economy grew 0.4% in the first quarter compared to the previous three-month period, outpacing expectations, a preliminary estimate from the national statistics agency INEGI showed on Friday. The seasonally-adjusted advance in gross domestic product (GDP) compared with the median forecast of a Reuters poll of analysts for an increase of 0.1% from the prior quarter. Compared with the same quarter a year earlier, the economy shrank 3.8% in unadjusted terms, INEGI said. That compared with a poll forecast for a contraction of 3.5% year-on-year. (Reporting by Anthony Esposito)