Preimplantation genetic diagnosis (PGD) - In sex selection cases, embryos resulting from IVF procedures are genetically tested for X or Y Chromosomes. The embryos of the desired sex are then implanted.
Sex-selective child abandonment - Abandoning children of the unwanted sex. Though illegal in most parts of the world, it is still practiced.
Sex-selective adoption - Placing children of the unwanted sex for adoption. Less commonly viewed as a method of social sex selection, adoption affords families that have a gender preference a legal means of choosing offspring of a particular sex.
Listed here are some ethical concerns:
Sexual discrimination - The idea that if one sex is preferred over another, those individuals in the non-preferred sex would be at a disadvantage. Opponents of social sex selection argue that the procedure would artificially unequalize the ratio of females to males, leading to discrimination, potential violence and abuse of the smaller group.
Eugenics - Many fear that PGD, in general, is a 'slippery slope' leading to a society where 'non-selected' individuals would be discriminated against. PGD is used primarily in the U.S. for the purpose of reducing birth defects and abnormalities, but opponents fear that there is nothing stopping persons from using PGD for more eugenic-based purposes.
Psychological Implications - There may be psychological implications for both the parents and child if the procedure does not produce a child of the desired sex. Furthermore, problems may also arise if the gender-related expectations of the parents are not subsequently fulfilled by the child. However, it may be the case that any child will fail to fulfill particular parental expectations, so perhaps more emphasis should be placed on promoting acceptance and tolerance within parents as opposed to completely banning sex selection.
Conflict with Kantian principles - Many argue that by selecting the sex of their child, parents are using the child as a means of fulfilling their own desires rather than respecting the child as a person and an end in their own right.
In contrast, there is widespread support for the concept that individual reproductive choice is an important private decision which should not be infringed by government. There is considerable evidence from sperm sorting in the United States that pre-conceptual use of this technology, which does not involve destruction of embryos or fetuses, is desired and utilized by many couples to achieve balancing of gender ratios within their families. Furthermore, the fear that there would be preferential selection of boys is clearly false - indeed, actual experience in the U.S. indicates that the technology is used more often to obtain girls than boys. Thus the real-world experiences with techniques such as MicroSort demonstrate that theoretical fears of gender discrimination from sperm sorting are not at all realized in a country such as the U.S. There is equally little real evidence in support of the other theoretical harms postulated by opponents of pre-conceptual gender selection.
Post-conceptual selection by preimplantation testing (PGD) is a distinct subject as it obviously involves preferential use of embryos, and of course termination of pregnancy for gender selection is a quite different matter.
In addition to the ethical concerns mentioned, issues of demographics arise in societies where social sex selection is common. A society may exhibit a widespread bias towards having children of a specific gender, either due to cultural biases or economic concerns (e.g. male children may be more employable in the future and thus provide more financial support). When combined with frequent social sex selection, this bias may produce a gender imbalance that has undesirable consequences. This phenomenon has been observed in many nations in the Far East, such as India and China, where social sex selection has produced unnaturally high male/female ratios in the population. China's gender imbalance is further increased by the One Child Policy. In these nations, a lack of opportunity for many men to marry is believed to be producing increases in crime, demand for prostitution, and the selling of brides.
In contrast, actual experience in Western cultures provides no evidence for any degree of gender imbalance from technologies which have long been available and legal - such as selective abortion or preimplantation embryo testing. When used for family balancing indications in such countries as the United States, pre-conceptual sex selection is widely sought without any preferential selection of males. Thus the right of individual families to determine whether or not to balance gender of offspring in their families is not and will not become, in many countries, a demographic issue. Furthermore, in countries where such demographic issues exist because of strong gender preferences in a segment of the population, regulatory and legal control of, without denial of access to, sperm sorting technology can be utilized to provide individuals with choices while ensuring that equal numbers of boys and girls are produced for population demographic equality.
Some people believe that timing conception according to astrological charts can influence a baby's sex, though there is no evidence to support this or any other timing method. A 13th century Chinese conception chart purports to be able to identify the sex of the baby before birth.
During the 1980s, Lawrence Livermore National Laboratories teamed with the United States Department of Agriculture to develop the first (and only) successful and repeatable means of separating X- (male) and Y- (female) chromosome bearing spermatozoa. Based on the DNA difference between the X and Y chromosome, the technique (known as 'Beltsfield Sperm Sexing Technology') uses flow cytometry to accurately separate each sub-population. Sperm sorting by flow cytometry is able to separate spermatozoa from most mammalian species, including humans . 'Sexed semen' is offered commercially in cattle by a variety of companies including Cogent (UK) and Sexing Technologies (USA). In humans the technique is marketed as 'MicroSort', but is unavailable outside of the USA due to legal restrictions.
Recently, a study published in 2006 indicated that mothers with toxoplasmosis have a significantly higher sex ratio of boys to girls. This has been discussed in connection with the manipulation hypothesis of parasites.
Social sex selection is illegal in India. To ensure this, prenatal determination of sex through ultrasound is also illegal in India. These laws are instituted to combat the prevalent practice of sex-selective abortion. However, these laws have generally failed to be effective and sex-selective abortion continues to be widely practised.
Sex selection is legal in most of the world, and its practice particularly in Western countries is far more limited than in India or China.