While abortion rates usually decline with increasing usage of modern contraceptives (Westoff, 2005; Shah and Ahman, 2004), they may rise due to a strong desire for smaller family size during periods of rapid fertility decline. Studies have shown an association between fertility transition and unwanted pregnancy in some developing countries, indicating a rise in unwanted pregnancies during the fertility transition, and remaining relatively high until the end of the transition period (Bankole and Westoff, 1995; Bongaarts, 2002). Contrary to other countries, the substantial fertility decline in the Islamic Republic of Iran has been accompanied by only a moderate rise in the age at first birth, which increased from 18.5 years in the 1980s to 21 years in the 1990s (Abbasi-Shavazi and Hosseini-Chavoshi, 2014).