The labor participation rate for 30-something South Korean women hit the highest level on record, data showed on Tuesday, suggesting a social trend in which females with higher education opt to work amid low fertility rates and delayed marriages.

The labor participation rate for women aged between 30 and 39 stood at 57 percent last year, the highest since 2000 when comparable data began to be compiled, according to Statistics Korea.

The labor force participation rate refers to the percentage of those who participate in the labor force by either having a job or actively seeking one.

The rate has been on a steady rise, reaching 54.2 percent in 2009, 55.3 percent in 2010, 55.5 percent in 2011 and 56 percent in 2012, the data showed.

In contrast, the rates for women in other age brackets showed little change. The labor participation rate for females in their 20s rose slightly to 62 percent last year from 61.8 percent in 2009, and the comparable figure for females in their 40s increased to 65.9 percent from 65.4 percent over the cited period, the data showed.

The sharp rise for females in their 30s is attributable to low birthrates and a decline in marriages.

"Low birth rates, among other things, would be the biggest reason (for the higher labor participation rate)," said Kim Young-ok, a researcher at the Korea Women's Development Institute.

Government data showed the number of babies born in South Korea dropped for the first time in four years in 2013. A total of 436,600 babies were born last year, down 48,000, or 9.9 percent, from a year earlier, marking the lowest since 2005. It also represented the first time that childbirths have declined on a year-on-year basis since 2009.

The data also show that the total fertility rate, or the average number of babies that a woman is projected to have during her lifetime, dropped to 1.19 last year from the previous year's 1.3. The crude birthrate -- the number of babies born per 1,000 people -- also fell to 8.6, the lowest level since related record-keeping began in 1970, the report showed.

The South Korean government has been trying to bring more women into the nation's workforce by encouraging companies to offer flexible hours and other incentives to help those who need to juggle home life and work. (Yonhap)