SEOUL (Reuters) - The South Korean president s office said on Sunday that it will begin a review on the country s 64-year-old law to ban abortion. The announcement came after more than 230,000 South Koreans filed a petition calling for the abolishment of the law. South Korea criminalized abortion in 1953 when its leaders wanted to boost the population and build an army powerful enough to fend off its rival North Korea. But in 1973, with population growth strong, the country drew up exceptions to the abortion law, such as where the mother s health is at risk, the baby is to be born with severe birth defects or the pregnancy was caused by a sexual crime. Many public health experts in South Korea pushed for changes in the abortion law but faced opposition from a strong pro-life lobby in a country with one of Asia s largest percentages of Christians and a government trying to boost one of the world s lowest fertility rates.  The president s office said the government will conduct research next year on the country s abortion cases for the first time since 2010.  Based on the outcome from the research, we expect to move relevant discussions one step forward,  Cho Kuk, the senior presidential secretary for civil affairs, said in a statement.     Cho said South Korea s Constitutional Court, which in 2012 upheld the anti-abortion law, will again review the legislation.    According to the most recent figures, an estimated 16,900 abortions were performed in 2010, and only 6 percent of them were done legally, he said. 