Nearly every woman in Pakistan has been witness or victim to it.
A woman, an aunt, a sister, becomes pregnant.
If she has daughters or even if she does not, the hope is for a boy. In the prayers old ladies bestow on the woman, to the vocalised aspirations of all relatives, the hope, the desire, the goal is a boy. For all but a few families, therefore, the birth of a girl is a loss.
Given the dynamics of shame in the country, some cover this up with forced smiles and platitudes; others visibly mourn and mope. The numbers for a while testified to the reality: 105.7 boys born for every 100 girls.
In parts of the world where such prejudice does not exist, the natural ratio so to speak, is usually about 50/50.
Expanded into millions it becomes a huge gap between men and women.
It was only a matter of time before technology was put into the service of patriarchy.
According to the Population Research Institute, that calls itself a non-profit research group, and that collects data on sex selective abortion, over 1.2 million female foetuses were aborted in Pakistan in the years between 2000 and 2014.
The yearly average of sex selective abortions is 116,384.
The numbers are reportedly trumped only by China and India, both of which have significantly larger populations than Pakistan and who see around 800,000 and 600,000 sex selective abortions every year.
The numbers are calculated using census numbers and life expectancy and then projecting the natural ratio and noting the disparity between what should be and what is.
These estimates may be surprising to some, at least in this sort of public presentation.
Reproductive health is in itself a loaded issue in Pakistan, where fertility and a woman's ability to give birth and then give birth to a son has huge impact on the quality of her life.
In private conversations, reproductive healthcare professionals tell of the onerous professional decisions they face when confronted with infertility issues.
Women, afraid of losing their marriages, will often beg their doctors to keep information from their in-laws.
In sum, the issue of a woman's ability to bear children is a fraught one.
With so much riding on the ability and possibility of a woman bearing a child, it is unsurprising that, even in educated families, misinformation and secrecy reigns.
Abortion for any reason is a taboo subject, with no statistics available as to who or why or when abortions are necessitated and what sort of care is available to women who have them.
Given the rest of Pakistan's dismal numbers on maternal health (the majority of poor women have virtually no access to healthcare) and the deplorable mix of coercion and abuse that hounds most women, it can safely be assumed that most who avail of them do so in secrecy, with a good number perishing in the process.
Life in general is cheap in Pakistan and women's lives even cheaper.
Numbers, however, do not lie. Sex selective abortions, where parents discover the gender of the foetus and then abort it, are obviously happening in Pakistan and at a rate higher than in Vietnam, Malaysia, Azerbaijan and others.
Nor is there any hope, it seems; with girls married off at younger ages (half of married women between the ages of 20-24 were married before they were even 18), little training for those providing reproductive health services and coercive in-laws and husbands wanting sons at any cost, the number of these abortions will most likely rise.
The high cost of raising children, expected only to get higher, is likely to facilitate its popularity; the country's increasingly urban character will add to it.
Boys after all are investments with rates of return; girls, we are told, are always liabilities.
Normally, the ever-vigilant religious vanguard of Pakistani society would rise up and rant against the killing of the unborn; but patriarchy, it seems, silences even the most pious and the issue of saving unborn girls does not appear on their agenda.
Should we feel sorry for the 1.2 million gone girls of Pakistan, the ones who were killed before they ever had a chance to live?
Instinct and empathy would say yes; a chance at life is after all a chance at change, at making something of oneself, at a future.
This sort of wish, however, aligns poorly with the realities of Pakistani society.
As a large number of unborn girls of Pakistan continue to be eliminated soon after they make their first appearances on this or that ultrasound monitor, as the number of gone girls rises from the hundreds of thousands a year to the millions, the men may notice. Future generations could see a Pakistan transformed from one where women are increasingly banished and invisible to one where women are simply not there anymore.
If the level of misogyny regularly witnessed in the pages of newspapers, the murders and kidnappings, the discrimination and abuse are any indicator, then it seems that the numbers of women could dwindle further.
This 'womanless' world, one that the country's men seem to want to create, by harassing and constraining, banning and eliminating, raping and disrespecting, would be a good fate for them.
Those that plan and plot and kill girls before they are born, who imagine their hushed act as having no consequences, would face the collective catastrophe brought on by a million others that thought the same.
In the meantime, many unborn girls of Pakistan are at risk or probably, gone girls.
The writer is an attorney teaching constitutional law and political philosophy.