Declining Twin Birth Rates in India and Bangladesh

Recent studies reveal a projected decline in twin births in India and Bangladesh by 2100. Despite this, India will continue to have one of the highest twin birth numbers globally due to its large population. This trend reflects changing fertility patterns, maternal age, and medical interventions affecting twinning rates.

Current Trends in Twin Births

India’s twin birth rate is expected to drop by about 10.5%, and Bangladesh’s by 20.2% by 2100. This decline is mainly due to fertility rates falling below replacement levels and fewer women having children. However, more women having children at older ages slightly offsets this decline, as older maternal age increases the likelihood of twins.

Medical Assisted Reproduction and Twinning

Medically assisted reproduction (MAR), including in vitro fertilisation (IVF) and ovulation induction, is a known factor increasing twin births in high-income countries. MAR use in India has grown over the past two decades but was not fully accounted for in projections. This suggests that future twin birth rates in India could be higher than current estimates.

Health Risks and Mortality Among Twins

Twins face higher health risks than single births. In India, twins account for 7.7% of under-five deaths despite being a small share of total births. Mortality rates for twins are 7.5 to 10 times higher in early neonatal stages compared to singletons. Wealth disparities affect twin survival, with poorer households facing greater risks.

Need for Twin Registries

Twin registries systematically track twin births and health outcomes. Countries like Sweden, Denmark, Finland, and Australia use these registries to study genetics, disease risks, and public health. Establishing a twin registry in India could improve healthcare for twins and aid research on gene-environment interactions.

Genetics, Environment and Twin Research

Twin studies help distinguish genetic influences from environmental factors in disease development. By analysing twins living in different environments, researchers can better understand conditions like asthma, Parkinson’s disease, and cancer. India’s urbanisation and pollution make such studies especially valuable for public health insights.

Policy and Public Health Implications

The rising maternal age and growing use of MAR require health systems to prepare for more twin pregnancies. Targeted interventions and training for frontline health workers can improve twin survival. A twin registry would support policy decisions and advance medical research in India and similar low-income countries.

Questions for UPSC:

1. Discuss in the light of recent demographic trends how declining fertility rates impact population structure and healthcare needs in India.
2. Analyse the role of medically assisted reproduction technologies in changing birth patterns and their socio-economic implications in developing countries.
3. Taking the example of twin mortality in India, critically discuss the challenges and strategies for improving neonatal healthcare in resource-constrained settings.
4. Examine how twin studies contribute to understanding the interaction between genetics and environment in disease epidemiology, with suitable examples.

Answer Hints:

1. Discuss in the light of recent demographic trends how declining fertility rates impact population structure and healthcare needs in India.

1. Declining fertility leads to slower population growth and an ageing population structure.
2. Lower birth rates reduce the proportion of young dependents, altering dependency ratios.
3. Healthcare needs shift from maternal and child health to geriatric and chronic disease care.
4. Declining fertility can reduce twin births, affecting specialized neonatal care demand.
5. Changing maternal age patterns (older mothers) increase risks in pregnancies, requiring advanced healthcare services.
6. Policy planning must adapt to these demographic shifts for resource allocation and health infrastructure.

2. Analyse the role of medically assisted reproduction technologies in changing birth patterns and their socio-economic implications in developing countries.

1. MAR increases twinning rates by enabling multiple embryo implantations (e.g., IVF, ovulation induction).
2. Growing MAR use in developing countries like India may raise twin births despite declining natural fertility.
3. Access to MAR is often limited to wealthier or urban populations, increasing socio-economic disparities.
4. MAR can help address infertility issues, impacting population growth and family planning dynamics.
5. Higher twin births from MAR increase healthcare costs due to higher maternal and neonatal risks.
6. Policy and regulation are needed to manage MAR use and ensure equitable access and safety.

3. Taking the example of twin mortality in India, critically discuss the challenges and strategies for improving neonatal healthcare in resource-constrained settings.

1. Twin mortality rates are higher than singletons, especially in early neonatal stages.
2. Challenges include limited healthcare infrastructure, poverty, and lack of specialized neonatal care.
3. Wealth disparities cause unequal access to quality maternal and neonatal services.
4. Strategies include training frontline health workers for twin-specific care and monitoring.
5. Establishing twin registries can improve tracking, research, and targeted interventions.
6. Community awareness and improved nutrition, hygiene, and antenatal care are essential.

4. Examine how twin studies contribute to understanding the interaction between genetics and environment in disease epidemiology, with suitable examples.

1. Twin studies help separate genetic factors from environmental influences on diseases.
2. Comparing monozygotic (identical) and dizygotic (fraternal) twins reveals heritability estimates.
3. Examples include studies on Parkinson’s disease, cancer, asthma, and cardiovascular diseases.
4. Environmental exposures like pollution and lifestyle differences between twins clarify non-genetic risks.
5. Twin registries in countries like Sweden and Denmark facilitate longitudinal health research.
6. In India, twin studies can explore urbanisation effects on respiratory diseases and immune system development.