GENERAL HEALTH

Pre-marital screening in India: the carrier test only works if both partners take it

In short

Beta-thalassaemia carrier screening changes what a couple can decide, and it is informative only when both partners are tested, because a carrier is healthy and the one-in-four risk in each pregnancy exists only when two carriers have children together.

Published 6 September 202615 min read
Two glass droplets each holding a faint helix, linked by a glass ring, with four small spheres above and one tinted amber, illustrating that carrier screening only means anything when both partners are tested

Carrier screening for thalassaemia changes what a couple can decide, and it only means anything when both partners are tested. Someone with beta-thalassaemia trait is not ill with thalassaemia and does not become ill with it, though the trait shows on a blood count as a small red cell. The risk arises only when two carriers have children together, and then it is one in four in every pregnancy, each pregnancy counted separately. The National Health Mission's 2016 guideline puts the average Indian carrier frequency at 3 to 4%, while the largest Indian survey it cites measured 2.78% (95% CI 2.66 to 2.94) across six cities. Carriage cannot be felt or seen, and no family history can confirm or exclude it. It is settled by a blood test.

Written by Dr. A. Ameer Jahan, Senior Consultant · Reproductive Medicine, Male Infertility & STD, Chairman, AJSMC, Egmore, Chennai (TNMC 28017). This page is about what pre-marital screening and counselling in India consist of, what each test can and cannot tell you, and what the law says about consent. The principal document it follows is Prevention and Control of Hemoglobinopathies in India — Thalassemias, Sickle Cell Disease and Other Variant Hemoglobins, National Health Mission, Ministry of Health & Family Welfare, Government of India, 2016. On consent to testing it follows the HIV and AIDS (Prevention and Control) Act, 2017.

Screening is for people who feel well, and a few of the things it turns up need a hospital the same day. Severe anaemia, decompensating liver disease in someone found to be hepatitis B or C positive, and a pain crisis in someone found to have sickle cell disease rather than trait all need transfusion and round-the-clock inpatient care that AJSMC's ten planned-admission beds cannot provide. A result arriving weeks before a wedding also carries psychological risk. Thoughts of harming yourself, after any result on this page, need help today. Call 108 or go to the nearest hospital with a 24-hour emergency department. AJSMC is a multi-speciality centre in Egmore with no casualty unit, no emergency department and no critical care: its ten beds take planned, stable admissions, with a nurse on site overnight and no doctor on the premises. Consultations run Monday to Saturday, 10am to 9pm, and it is closed all day Sunday.

What is actually on a pre-marital screening panel, and who recommends it?

No Indian national guideline or programme document prescribes a standard pre-marital panel. The list a Chennai laboratory prints on a card is clinical convention, not policy, which does not make the individual tests on it useless; it means the panel was never designed as one. The nearest official statement is in the 2016 haemoglobinopathies guideline, and it concerns antenatal screening: testing in pregnancy "can be integrated with testing for HIV, hepatitis B, VDRL, diabetes mellitus, hypothyroidism etc."

TestWhat it is forRecommended before marriage by an Indian guideline?
Haemoglobinopathy carrier screeningFinding two carriers before they have childrenThe 2016 guideline offers it only to "those individuals or couples who seek it"
Complete blood countAnaemia, and the MCV and MCH a carrier result is read againstPart of the same guideline's confirmatory step
HIV testKnowing your own status, voluntarilyNo. No Indian law requires it before marriage
Hepatitis B surface antigenChronic infection, which matters for a partner and a newbornNo. India screens selectively in pregnancy
Rubella IgG (women)Immunity, because NG257 1.20.2 says those found susceptible should be offered vaccination before a pregnancy rather than during oneNo Indian recommendation for adults. NICE advises it where fertility is a concern
Blood group and RhKnowing an Rh-negative woman will need anti-D in a pregnancyNo. The rationale is antenatal
Syphilis serologyA treatable infection that damages a pregnancy if missedAntenatal only

Sources: NHM/MoHFW, Prevention and Control of Hemoglobinopathies in India, 2016; HIV and AIDS (Prevention and Control) Act, 2017, ss.5–6; National Viral Hepatitis Control Programme Operational Guidelines, MoHFW, 2018; NICE guideline NG257, Fertility problems, 31 March 2026, recommendations 1.20.1 and 1.20.2.

Why does carrier screening only work if both of you are tested?

Because a carrier result acquires meaning only alongside a partner's. Beta-thalassaemia trait is recessive: one altered copy causes no illness, and most carriers in India have never been told they are one. Two carriers face a one in four chance in each pregnancy of a child with thalassaemia major. A carrier already known in the family is a reason to be tested, not a substitute for testing.

The 2016 guideline states the purpose bluntly: "identification of carriers before marriage so as to avoid marriage between two carriers to eliminate possibility of birth of an affected child." It is equally firm that this is an offer, holding that "genetic testing should always be voluntary" and preceded by "non-directive genetic counseling", and that public health goals "should never be set in ways to impose genetic tests or reproductive decisions on individuals."

It also ranks the timings, and pre-marital is not its favourite: adolescent screening is "most suitable for carrier screening, as a long term sustainable strategy", while pre-marital screening is "effective in a well-informed community". A result arriving between an engagement and a wedding lands in the hardest place, where the guideline says the decision "becomes a delicate issue at this stage and will depend on the families and the couple's level of emotional bonding."

What is the national programme called, and what does it cover?

The haemoglobinopathies document above is a guideline. The funded programme is separate: the National Sickle Cell Anaemia Elimination Mission, run under the National Health Mission, which aims to eliminate sickle cell disease as a public health problem in India before 2047 and to cover 7 crore people across 17 higher-prevalence states, Tamil Nadu among them. Its strategy includes "mechanisms to be established at community level for pre-marital and pre-conception screening backed by genetic counselling services".

On burden, no single national number should be trusted. The 2016 guideline estimates almost 42 million carriers and 10,000 to 15,000 affected babies a year, but cites nothing at all for the 42 million and traces the 10,000 to 15,000 to a single 2008 book chapter. Published estimates elsewhere are lower: 8,000 to 10,000 in the six-city paper's own introduction, and 7,500 to 12,000 in a 2022 review by that study's senior author (Colah and Seth, Hemoglobin 2022;46:20–26). The largest survey the guideline cites, the ICMR six-city study of 56,780 people (Mohanty, Colah and colleagues, Journal of Community Genetics 2013;4:33–42), measured an overall beta-thalassaemia trait prevalence of 2.78% (95% CI 2.66 to 2.94), ranging from 1.48% to 3.64% between states and from 0 to 9.3% across 59 ethnic groups. Tamil Nadu was not among the six states.

How is carrier status confirmed on a blood test?

In two steps. India's protocol uses NESTROFT for beta-thalassaemia trait, the DCIP test for HbE trait and a solubility test for HbS trait, on a finger-prick sample alongside a haemoglobin reading. Anything screening positive, with a haemoglobin of 8 g/dL or more, goes on to a complete blood count and high-performance liquid chromatography.

FindingValueSource
NormalHbA2 2.3–3.5%, HbF below 2.0%, MCV 80–100 fL, MCH 27–32 pgNHM/MoHFW, 2016, Table 4
Beta-thalassaemia traitHbA2 4.0–8.0%, HbF 0.5–4.0%, reduced MCV and MCHNHM/MoHFW, 2016, Table 4
Equivocal, needs evaluationHbA2 between 3.5% and 3.9%NHM/MoHFW, 2016, Table 4 footnote
HbS traitHbA2 3–4%, variant haemoglobin 35–40%NHM/MoHFW, 2016, Table 4
HbE and HbD traitHbA2 normal, which is why HPLC rather than HbA2 alone is confirmatoryNHM/MoHFW, 2016, Table 4

Iron deficiency confounds this, so the guideline asks for serum ferritin where HbA2 falls in the equivocal band, and where HbA2 is diagnostic but haemoglobin is below 12 g/dL. It also makes cascade screening of the siblings and wider family of a detected carrier "an integral component of the screening strategy protocol".

Can anyone require you to have an HIV test before marriage?

No. Not a family, not a prospective spouse, not a broker, not an employer, not a clinic. The belief that a pre-marital HIV certificate can be demanded is widespread and it is wrong in Indian law.

Section 5 of the HIV and AIDS (Prevention and Control) Act, 2017 states that no HIV test shall be undertaken or performed upon any person except with that person's informed consent, and requires that the consent include pre-test and post-test counselling. Section 6 lists exhaustively the only situations where consent is not required: a court order that the test is necessary to determine issues before it; use of a human body or body part for research or therapy; anonymous surveillance testing; and screening in a licensed blood bank. Marriage is not on that list.

Section 3(l) makes it prohibited discrimination to require HIV testing as a prerequisite for employment, healthcare or education, "or for accessing or using any other service or facility". Section 2(n) defines informed consent as consent given "without any coercion, undue influence, fraud, mistake or misrepresentation", so a test agreed to under family pressure is not consent in the sense the Act uses. Section 8(1) forbids compelling anyone to disclose his HIV status except by order of a court, and forbids anyone in a fiduciary relationship from disclosing another's status except with written informed consent: a doctor cannot hand your result to your fiancé, your parents or your prospective in-laws.

Section 9 opens one narrow route by which a partner may be told: only a physician or a counsellor may use it, all four statutory conditions must be met, and a proviso bars disclosure where there is reasonable apprehension of violence, abandonment or serious harm to a woman, her children or her relatives. Section 10 puts the duty to take reasonable precautions, including disclosure before sexual contact, on the person themselves. Goa's government has proposed compulsory pre-marital testing more than once, in 2006 and again publicly since; this page does not say any such law is in force, because no gazette notification establishing one could be traced to a primary source.

Does it matter that you are marrying a cousin?

More often than most couples expect, and less consequentially than the fear around it suggests. Tamil Nadu has the highest rate of consanguineous marriage of any state in India.

PopulationEver-married women aged 15–49 married to a blood relativeSource
Tamil Nadu27.9%, the highest of any state or union territory. First cousin on the father's side 10.0%, mother's side 11.2%, uncle 1.2%NFHS-5, 2019–21, Table 6.6
Karnataka / Andhra Pradesh26.6% / 26.4%NFHS-5, Table 6.6
Kerala4.4%NFHS-5, Table 6.6
India10.8%. Urban 11.0%, rural 10.7%NFHS-5, Table 6.5

The figures come from the National Family Health Survey (NFHS-5), IIPS and ICF, 2019–21, DHS Final Report FR375, covering 552,040 ever-married women. Note the last row: consanguinity is a normal family structure across the southern states except Kerala, in cities as much as villages.

Related parents share ancestors, so they are likelier to carry the same recessive variant. The excess risk of a significant congenital anomaly in the offspring of first cousins is usually given as 1.7 to 2.8 percentage points above the risk the general population already faces (Bennett, Motulsky, Bittles and colleagues, Journal of Genetic Counseling 2002;11:97–119, restated in the Geneva International Consanguinity Workshop Report, Hamamy and colleagues, Genetics in Medicine 2011;13:841–847). Because that excess is driven by recessive conditions, it concentrates in a small minority of couples, which is what carrier screening and a family history are for. Sources disagree on the size: in the Born in Bradford cohort, congenital anomaly affected 2.3% of births to unrelated White British couples and 2.6% of births to unrelated Pakistani couples, against 6.2% of births to Pakistani first-cousin couples, an adjusted risk ratio of 2.19 (95% CI 1.67 to 2.85) (Sheridan and colleagues, Lancet 2013;382:1350–1359). None of this evidence is Indian, and no verified Tamil Nadu figure exists.

Consanguinity has not been shown to cause infertility or recurrent miscarriage. The legal question sits apart from the clinical one. Sections 5(iv) and 5(v) of the Hindu Marriage Act, 1955 require that the parties are not sapindas of each other and not within the degrees of prohibited relationship, "unless the custom or usage governing each of them permits of a marriage between the two". The exception is narrow: the custom must govern both parties, and section 3(a) requires it to have been observed continuously and uniformly for a long time and to have obtained the force of law. A marriage outside that exception is void under section 11. Anyone with a question about legal validity should take independent legal advice.

Do you need a rubella test before marriage?

The useful version of this question is about timing. Rubella infection early in pregnancy can cause miscarriage, foetal death or congenital rubella syndrome, and WHO describes rubella as the most common infectious cause of birth defects. WHO also says the vaccine should be avoided in pregnancy and advises women planning a pregnancy to avoid conceiving for a month after it. India's national immunisation schedule contains measles-rubella vaccine at 9–12 months and 16–24 months and no adult dose, so rubella protection for an adult woman sits outside the national programme entirely. Whether immunity should be established, and how, is a decision for the doctor before any pregnancy.

How many Indian women are susceptible is less settled than it looks. ICMR-coordinated serosurveys of 3,585 pregnant women aged 16–39 at sentinel surveillance hospitals in 2017 and 2019–20 found 16.2% seronegative, which the authors summarised as about one fifth of women of reproductive age being susceptible, citing a published review range of 12 to 30% (Shanmugasundaram and colleagues, PLOS Neglected Tropical Diseases 2021;15(7):e0009608). A thirteen-site survey by the same group in August to October 2022 found seroprevalence of 85.2% (95% CI 84.0 to 86.2), roughly 15% susceptible (Vaccine 2024;42:126077). Ten of the twelve earlier sites were urban and none randomly chosen, and a district survey in Palghar, Maharashtra found about 9% susceptible (91% seropositive, 95% CI 87.2 to 94.8). The women surveyed in 2019–20 were almost all too old to have been reached by the 2017 childhood campaign, so susceptibility should fall further as vaccinated cohorts age in.

Where do hepatitis B, blood group and Rh fit in?

The case for hepatitis B testing rests on grounds that have nothing to do with marriage. The National Viral Hepatitis Control Programme, launched by the Ministry of Health and Family Welfare on 28 July 2018, records HBsAg positivity in the general population ranging from 1.1% to 12.2%, average 3 to 4%, with around 40 million people chronically infected. Most do not know. It is transmissible to a partner and to a newborn, and knowing your status is what allows either of those to be managed; the birth dose within 24 hours is already part of India's national immunisation schedule. What follows a positive result is a clinical decision, taken with the doctor who reads the report.

Blood group and Rh typing is on every pre-marital card in the city, and no Indian guideline recommends it before marriage. Its purpose is antenatal: identifying an Rh-negative woman who will need anti-D arrangements in a future pregnancy. Anyone told that an Rh mismatch between partners is a reason not to marry has been misinformed. It is a pregnancy management issue with a settled answer, not a compatibility test.

What can genetic counselling tell you, and what can it not?

It can tell you what a specific result means for a specific couple, in numbers, and what the options are. It can take a three-generation family history, which carrier screening cannot substitute for, and say when in a pregnancy prenatal diagnosis must happen to be useful. The 2016 guideline names the two options to be reinforced with a detected carrier: avoiding marriage with another carrier, and opting for antenatal screening after marriage.

What it cannot do is larger. It cannot tell you a child will be healthy, because carrier screening looks for a defined list of conditions and is silent on everything else, and it cannot resolve whether a couple should marry. If a result is going to be given, the time to give it properly should be arranged when the test is.

Does age change how long conception takes?

Yes, gradually, and the honest numbers are less frightening than the conversation usually is. NICE puts it at more than 80% of heterosexual couples conceiving within one year if the woman is under 40, they use no contraception and they have regular intercourse; of those who do not, about half conceive in the second year.

Woman's ageCumulative probability of clinical pregnancy without any treatment, after 12 cyclesAfter 24 cycles, untreated
19–26 years92%98%
27–29 years87%95%
30–34 years86%94%
35–39 years82%90%

Source: NICE guideline NG257, 31 March 2026, Table 1, from Dunson, Baird and Colombo, Obstetrics and Gynecology 2004;103:51–6, assuming intercourse twice a week. The table stops at 39 and must not be extrapolated past it. The second-year column matters: a year without conception is common and is not by itself a diagnosis.

Does counselling about the marriage itself work?

Partly, modestly, and the evidence is not Indian. A meta-analysis of 86 reports covering 117 studies found, for the experimental studies, effect sizes of d = .30 to .36 for relationship quality and d = .43 to .45 for communication skills (Hawkins and colleagues, Journal of Consulting and Clinical Psychology 2008;76:723–734). A follow-up of 47 studies found that once unpublished work was included, premarital education did not improve relationship quality or satisfaction, though it still appeared to improve communication (Fawcett and colleagues, Family Relations 2010;59:232–239). Every study located is Western, with short follow-up, and no Indian trial could be found. What the conversation is for, in practice, is the questions that never get asked in front of families: whether either of you wants children and when, and what contraception you will use in the first years.

When should you see a doctor?

Book early. Three months before a wedding is comfortable; three weeks is not, because a confirmatory test, a partner's test and a counselling conversation do not compress well. Come as a couple if you both want to, and alone if you do not, since nothing here permits a partner's consent to stand in for yours.

Bring any previous blood report, particularly a complete blood count or an HPLC, with its date, and your immunisation record. Bring a list of any illness in either family that repeated across siblings or cousins, especially a child who needed regular transfusions or died young. Say when you book if either of you is already known to be a carrier, and say so plainly if a test is being asked of you by someone other than yourself: a request from a family or a broker is a reason to talk to a doctor alone.

Ask to be seen sooner for symptoms rather than a screening question, such as unexplained tiredness with breathlessness, jaundice, a genital ulcer or discharge, or pain during intercourse. Do not come here at all, and do not wait for opening hours, for severe anaemia with breathlessness or fainting, jaundice with confusion or bleeding, severe pain in someone with sickle cell disease, or thoughts of harming yourself. Call 108 or go to the nearest hospital with a 24-hour emergency department. AJSMC has no casualty unit and no critical care, its ten beds take planned, stable admissions only, and it does not perform ART; where that is what a couple needs, the destination is a registered ART centre. For an outpatient consultation, AJSMC is on Police Commissioner Office Road, Egmore, Chennai 600008, Monday to Saturday, 10am to 9pm, on 044 2532 2021. Before you travel, ask on that number which tests are run in-house and which are sent to a referral laboratory.

This article is for general information and is not a substitute for a consultation. AJSMC does not run a casualty or trauma unit — in a life-threatening emergency call 108 or go directly to the nearest hospital with a 24-hour emergency department. For appointments and questions our helpline is answered 24 hours on 044 2532 2021.

Talk to a doctor

Still not sure what applies to you?

An article can tell you what usually happens. It cannot examine you. Bring your reports to a consultant at AJSMC in Egmore and get an answer about your own case.

FAQ

Questions people ask after reading this

No. The National Health Mission's 2016 haemoglobinopathies guideline says carrier screening before marriage is "to be offered to those individuals or couples who seek it", and binds itself to the WHO position that genetic testing should always be voluntary. Section 5 of the HIV and AIDS (Prevention and Control) Act, 2017 requires informed consent for any HIV test, and section 6's list of exceptions does not include marriage. No enacted, notified and enforced state law making any pre-marital test compulsory could be traced to a primary source.

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