From the study: An Economic Analysis of Abortion: The Effect of Travel Cost on Teenagers.
The authors find that a teen with a higher wage (i.e., a higher opportunity cost associated with time out of the labor force to raise a child) is more likely to have an abortion. In addition, teenagers who live in poverty are shown to be less likely to abort a pregnancy. Leibowitz et al. (1986) use individual data on the first pregnancy of unmarried teenage women in Ventura County, California: teens who are enrolled in school and those who perform well in school are shown to be more likely to have an abortion; since schooling is a measure of the opportunity cost of giving birth in terms of future wages, this result implies that the value of a teen's time is a factor in the teenage abortion decision. Ohsfeldt and Gohmann (1994) use state-le vel data to show that the price of abortion services and income are negatively related to teenage rates of abortion and pregnancy. Hass-Wilson (1996) gives evidence that U.S. states with parental notification and consent laws and those with more Medicaid funding restrictions have lower teenage abortion rates; because these laws effectively raise the cost to a teenager of obtaining an abortion, these results imply that abortion cost is important in the abortion decision process for teens. Lundberg and Plotnick (1995) use the NLSY and find that teens who live in states that offer funding for abortions have a higher probability of aborting a pregnancy.Source: The Social Science Journal:January 01, 2000 : JEWELL, R. TODD; BROWN, ROBERT W.The literature shows that abortion restrictions lead to fewer abortions among teenage women, possibly due to an increase in the monetary or psychic cost of obtaining an abortion. There can be legal restrictions, such as parental consent laws, or geographical restrictions in the number or location of abortion facilities. The research on parental consents laws implies that raising the cost of abortion services, either by reducing teens' accessibility to abortion services or by increasing the psychic cost associated with gaining parental consent, reduces the number of teen abortions. Likewise, reducing the availability of abortion services effectively raises the travel cost associated with acquiring an abortion; if the demand for abortions is sensitive to this price increase, then restricting availability will reduce the quantity of abortions demanded. Results from Haas-Wilson (1996) and Lundberg and Plotnick (1995) suggest that teens who live in states with greater abortion availability are more likely to have an abortion. In a related study, Kane and Staiger (1996) use county-level data from U.S. states to show that local abortion availability affects the teen birthrate; however, the authors do not estimate the relationship between local abortion availability and the teen abortion rate. Dayek and Smith (1976) and Brown and Jewell (1996) investigate the connection between local abortion availability and abortion demand, but neither study focuses on teenage women.
An abstract of the entire source can be found here: ScienceDirect - The Social Science Journal : An economic analysis of abortion: the effect of travel cost on teenagers
So while your assumption is that abortions are preventative of lower income/drug dependent families having children, the evidence points to the contrary.
The major contributor to the sudden stagnation in economic growth is due to the flattening of the population growth rate. This can be caused by a multitude of factors, namely birth rate, although immigration rate/policy is also integral to the discussion. Although common among developed economies, increasing population has been considered the most effective way to spur economic growth.
Which is my point BTW...