Between 23 and 45 million women have gone'missing' since the 1970s due to sex-selective abortions in China, India and ten other countries.
A new study has shown that these same countries will lose 4.7 million more female births by 2030, which could further skew their sex ratios.
This study is based on 3.26 Billion birth records from 204 nations. It identifies 12 countries with strong evidence of a skewed ratio and 17 at risk.
Good news is that 12 countries with a high sex ratio are showing signs of improvement, particularly China and India where 95 percent of missing births are currently located.
The model predicts that these countries will lose 5.7 millions women by 2100. This is a fraction of the loss since 1970s when sex diagnosis was widely available. It also shows a faster decline than other studies.
However, this is a large number of women who won't be born and could have lasting cultural and social repercussions.
A marriage squeeze in China and India has already caused a worrying increase in loneliness and violence as well as female trafficking and prostitution in countries like India and China.
Recent years have seen a decrease in sex inequality between these two countries, with government officials offering incentives for female births as well as restrictions on sex selective abortions.
However, there is still much to be done. According to the team behind the model, we must take immediate action to balance the sex in countries like China, India and Armenia.
It could also set precedent elsewhere.
The new model predicts that 22 million more women could be lost by 2100 if other countries like Nigeria, Pakistan and Egypt favor sons over daughters.
This scenario could see sub-Saharan Africa contributing more than a third to all the lost births.
Although it is a hypothetical scenario, as sex diagnoses and abortions become more easily available all over the globe and gender discrimination persists, it is possible.
Although abortion gives women control over their bodies, health and future, it can also make them less likely to choose well. Gender discrimination is a serious problem in the world, but in certain cultures only men are allowed to work, care for their elderly parents, or carry on the family's line of succession.
Women can't work, own property or have any other assets. In some cases, they may need a dowry in order to get married. This cultural expectation makes them a burden, even if they are not at fault, particularly for poorer families.
Researchers have also attributed the missing millions of women to poor female healthcare and female infanticide, in addition to sex-based abortion.
Although it is difficult to predict the future, we can be sure that these attitudes will change. Given the importance of sex ratios in determining the well-being and health of a nation,
Although the model isn’t perfect, it is the first attempt by researchers to predict the number of sons and daughters to be born over the next few years.
The authors state that these findings "underline the necessity to monitor [the gender ratio at birth] for countries with preference for sons and to address the causes of persistent gender bias in families, institutions and households."
"A larger objective is to influence gender norms that lie at the heart of harmful practices like prenatal sex select."
The study was published by BMJ Global Health.