Wrong. Aid programs slow the trend which, if real (since the graph has no source), is probably being caused by pollution, disease, and malnutrition.
One example is of how poor sanitation may lead to birth defects - a fact that can be mitigated purely by education.
Lead and mercury poisoning in children can also cause lifelong cognitive defects. This exposure can occur, among other ways, in the following manner:
"Health-damaging exposure to environmental risks can begin before birth. Lead in air, mercury in food and other chemicals can result in long-term, often irreversible effects, such as infertility, miscarriage, and birth defects. Women's exposure to pesticides, solvents and persistent organic pollutants may potentially affect the health of the fetus. Additionally, while the overall benefits of breastfeeding are recognized, the health of the newborn may be affected by high levels of contaminants in breast milk. Small children, whose bodies are rapidly developing, are particularly susceptible - and in some instances the health impacts may only emerge later in life." - WHO: The environment and health for children and their mothers
They drink contaminated water for a lack of options - a fact aid programs try to change.
Aid workers also promoted the use of condoms, especially in Africa where AIDS is rampant, both to prevent STIs and as a means of birth-control. Unless the OP considers the Catholic Church a leftist organization, it was the reactionary right that fucked up the program.
I could go on, and in a lot more detail, about how many ways the OP is wrong.