Passage: In the developing world, birth control increases economic growth due to there being fewer dependent children and thus more women participating in or increased contribution to the workforce. Women's earnings, assets, body mass index, and their children's schooling and body mass index all improve with greater access to birth control. Family planning, via the use of modern birth control, is one of the most cost-effective health interventions. For every dollar spent, the United Nations estimates that two to six dollars are saved. These cost savings are related to preventing unplanned pregnancies and decreasing the spread of sexually transmitted illnesses. While all methods are beneficial financially, the use of copper IUDs resulted in the greatest savings.The total medical cost for a pregnancy, delivery and care of a newborn in the United States is on average $21,000 for a vaginal delivery and $31,000 for a caesarean delivery as of 2012. In most other countries, the cost is less than half. For a child born in 2011, an average US family will spend $235,000 over 17 years to raise them.

Question: The savings that have been accumulated have done a good job at what?
preventing unplanned pregnancies and decreasing the spread of sexually transmitted illnesses