Prenatal sex discernment is the

prenatal test Prenatal testing consists of prenatal screening and prenatal diagnosis, which are aspects of prenatal care that focus on detecting problems with the pregnancy as early as possible. These may be anatomic and physiologic problems with the health ...

ing for discerning the sex of a

fetus A fetus or foetus (; plural fetuses, feti, foetuses, or foeti) is the unborn offspring that develops from an animal embryo. Following embryonic development the fetal stage of development takes place. In human prenatal development, fetal dev ...

before birth.

Methods

Prenatal sex discernment can be performed by

preimplantation genetic diagnosis Preimplantation genetic diagnosis (PGD or PIGD) is the genetic profiling of embryos prior to implantation (as a form of embryo profiling), and sometimes even of oocytes prior to fertilization. PGD is considered in a similar fashion to prenatal ...

before conception, but this method may not always be classified as ''prenatal sex discernment'' because it's performed even before implantation. *

Cell-free fetal DNA Cell-free fetal DNA (cffDNA) is fetal DNA that circulates freely in the maternal blood. Maternal blood is sampled by venipuncture. Analysis of cffDNA is a method of non-invasive prenatal diagnosis frequently ordered for pregnant women of advance ...

testing, wherein a

venipuncture In medicine, venipuncture or venepuncture is the process of obtaining intravenous access for the purpose of venous blood sampling (also called ''phlebotomy'') or intravenous therapy. In healthcare, this procedure is performed by medical labor ...

is performed on the mother to analyze the small amount of fetal DNA that can be found within it. It provides the earliest post-implantation test. A meta-analysis published in 2011 found that such tests are reliable more than 98% of the time, as long as they are taken after the seventh week of pregnancy. *

Chorionic villus sampling Chorionic villus sampling (CVS), sometimes called "chorionic ''villous'' sampling" (as "villous" is the adjectival form of the word "villus"), is a form of prenatal diagnosis done to determine chromosomal or genetic disorders in the fetus. It ent ...

(CVS) and

amniocentesis Amniocentesis is a medical procedure used primarily in the prenatal diagnosis of genetic conditions. It has other uses such as in the assessment of infection and fetal lung maturity. Prenatal diagnostic testing, which includes amniocentesis, is n ...

are two rather invasive testing procedures. These may, in principle, be performed as early as the 8th and the 9th week of pregnancy. The difficulty of these tests and the risk of injury to the foetus, potentially resulting in

miscarriage Miscarriage, also known in medical terms as a spontaneous abortion and pregnancy loss, is the death of an embryo or fetus before it is able to survive independently. Miscarriage before 6 weeks of gestation is defined by ESHRE as biochemica ...

or congenital abnormalities (especially when done early during the pregnancy), make them quite rare during the first trimester. In the United States, CVS and

are most commonly performed after the 11th and the 15th week of

pregnancy Pregnancy is the time during which one or more offspring develops ( gestates) inside a woman's uterus (womb). A multiple pregnancy involves more than one offspring, such as with twins. Pregnancy usually occurs by sexual intercourse, but ...

. *

Obstetric ultrasonography Obstetric ultrasonography, or prenatal ultrasound, is the use of medical ultrasonography in pregnancy, in which sound waves are used to create real-time visual images of the developing embryo or fetus in the uterus (womb). The procedure is a stan ...

, either transvaginally or transabdominally, can check for the ''sagittal sign'' as a marker of foetal sex. It can be performed between 65 and 69 days from fertilization (week 12 of

gestational age In obstetrics, gestational age is a measure of the age of a pregnancy which is taken from the beginning of the woman's last menstrual period (LMP), or the corresponding age of the gestation as estimated by a more accurate method if available. Su ...

), where it gives a result in 90% of cases – a result that is correct in approximately of cases, according to a study from 2001. Accuracy for males is approximately 50% and for females almost 100%. When performed later, after 70 days from fertilization (at week 13 of gestational age), it gives an accurate result in almost 100% of cases.

Applications

Potential applications of prenatal sex discernment include: *Disease testing: A complement to specific gene testing for

monogenic disorder A genetic disorder is a health problem caused by one or more abnormalities in the genome. It can be caused by a mutation in a single gene (monogenic) or multiple genes (polygenic) or by a chromosomal abnormality. Although polygenic disorders ...

s, which can be very useful for genetic diseases with

sex linkage Sex linked describes the sex-specific patterns of inheritance and presentation when a gene mutation (allele) is present on a sex chromosome (allosome) rather than a non-sex chromosome (autosome). In humans, these are termed X-linked recessive, ...

, such as, for example, X-linked diseases. In such cases, it may be much easier to exclude the possibility of disease in the child by prenatal sex discernment than to test for any specific sign of the disease itself. Common

X-linked recessive disorders Sex linked describes the sex-specific patterns of inheritance and presentation when a gene mutation (allele) is present on a sex chromosome (allosome) rather than a non-sex chromosome (autosome). In humans, these are termed X-linked recessive, ...

include

Duchenne muscular dystrophy Duchenne muscular dystrophy (DMD) is a severe type of muscular dystrophy that primarily affects boys. Muscle weakness usually begins around the age of four, and worsens quickly. Muscle loss typically occurs first in the thighs and pelvis follow ...

fragile X syndrome Fragile X syndrome (FXS) is a genetic disorder characterized by mild-to-moderate intellectual disability. The average IQ in males with FXS is under 55, while about two thirds of affected females are intellectually disabled. Physical features ma ...

and

haemophilia Haemophilia, or hemophilia (), is a mostly inherited genetic disorder that impairs the body's ability to make blood clots, a process needed to stop bleeding. This results in people bleeding for a longer time after an injury, easy bruisin ...

. *Preparation, for any sex-dependent aspects of parenting. *

Sex selection Sex selection is the attempt to control the sex of the offspring to achieve a desired sex. It can be accomplished in several ways, both pre- and post-implantation of an embryo, as well as at childbirth. It has been marketed under the title family ...

, which after preimplantation genetic diagnosis may be performed by selecting only embryos of the preferred sex, or, after post-implantation methods by performing

sex-selective abortion Sex-selective abortion is the practice of terminating a pregnancy based upon the predicted sex of the infant. The selective abortion of female fetuses is most common where male children are valued over female children, especially in parts of Eas ...

depending on the test result and personal preference. A 2006 surve

found that 42 per cent of

IVF In vitro fertilisation (IVF) is a process of fertilisation where an egg is combined with sperm in vitro ("in glass"). The process involves monitoring and stimulating an individual's ovulatory process, removing an ovum or ova (egg or eggs) f ...

clinics in the US that offer PGD have provided it for sex selection for non-medical reasons. Nearly half of these clinics perform it only for "family balancing", which is where a couple with two or more children of one sex desire a child of the other, but half do not restrict sex selection to family balancing. In India, this practice has been used to select only male embryos although this practice is illegal. Opinions on whether sex selection for non-medical reasons is ethically acceptable differ widely, as exemplified by the fact that the

European Society of Human Reproduction and Embryology The European Society of Human Reproduction and Embryology (ESHRE) was founded in 1985 by Robert Edwards ( University of Cambridge) and J. Cohen ( Paris), who felt that the study and research in the field of reproduction needed to be encouraged an ...

Task Force could not formulate a uniform recommendation.

Legal status

India

Prenatal sex determination was banned in India in 1994, under the

Pre-Conception and Pre-Natal Diagnostic Techniques Act, 1994 Pre-Conception and Pre-Natal Diagnostic Techniques (PCPNDT) Act, 1994 is an Act of the Parliament of India enacted to stop female foeticides and arrest the declining sex ratio in India. The act banned prenatal sex determination. Every genetic ...

. The act aims to prevent

, which, according to the Indian Ministry of Health and Family Welfare, "has its roots in India's long history of strong patriarchal influence in all spheres of life". Prenatal sex determination has caused the

Child sex ratio In India, the child sex ratio is defined as the number of females per thousand males in the age group 0–6 years in a human population. Thus it is equal to 1000 x the reciprocal of the sex ratio (ratio of males to females in a population) in t ...

to go down at alarming rates, in India, which is also another factor that led to its banning. However, the

Supreme Court of India The Supreme Court of India ( IAST: ) is the supreme judicial authority of India and is the highest court of the Republic of India under the constitution. It is the most senior constitutional court, has the final decision in all legal matters ...

has accused the

Government of India The Government of India ( ISO: ; often abbreviated as GoI), known as the Union Government or Central Government but often simply as the Centre, is the national government of the Republic of India, a federal democracy located in South Asia, ...

of poor

implementation Implementation is the realization of an application, or execution of a plan, idea, model, design, specification, standard, algorithm, or policy. Industry-specific definitions Computer science In computer science, an implementation is a real ...

and

enforcement Enforcement is the proper execution of the process of ensuring compliance with laws, regulations, rules, standards, and social norms. Governments attempt to effectuate successful implementation of policies by enforcing laws and regulations. E ...

of the act. Over time, there has been a substitution effect of more families participating in pre-natal sex determination instead of the previously popular act of

female foeticide Sex-selective abortion is the practice of terminating a pregnancy based upon the predicted sex of the infant. The selective abortion of female fetuses is most common where male children are valued over female children, especially in parts of Eas ...

China

On May 1, 2016, sex determination and sex-selective abortion were prohibited. Doctors are forbidden by the state from revealing the sex of unborn babies in an effort to stop prospective parents from finding out the gender of their child and potentially abort or abandon babies.

References