News: New analyses on twinning rates and twin mortality, including projections for India and a call to establish a twin registry, have refreshed policy attention.
About Twinning Rate
- The twinning rate is the number of twin births per 1,000 deliveries.
- Indicator of: It indicates how common twin pregnancies are and helps public health systems plan for higher-risk care and understand fertility patterns.
- Study of Twinning Rates
- Recent studies analyzed 3 million+ births across 39 low-income countries, projecting future twinning with UN population data.
- A separate India study used all five NFHS rounds (1993–2021) to track twin births and deaths.
Key Findings of Studies
India
- Rising twinning: The proportion of twin births increased from 0.9% in 1993 to 1.5% in 2021.
- Mortality burden: Twins formed 7.7% of all under-five deaths; mortality declined over time but remained high at 179.8 per 1,000 live births in 2021.
- Excess risk vs singletons: Death risk was 7.5 times higher in the early neonatal phase and 10 times higher in the late neonatal phase.
- Wealth gradient: Twin survival varied sharply by household wealth, identifying twins as a vulnerable group needing targeted interventions.
- Birth-order nuance: Twins are more often born in later pregnancies, yet twins born in the first or second pregnancy face higher death risk.
- India projections: Twin births are projected to decline by about 10.5% by 2100, but India may still hold the largest share (23.4%) among studied countries; projections may underestimate future twinning because growing use of medically assisted reproduction was not included.
Global
- The absolute number of twin births will rise in many countries due to population growth.
- South Asia, including India and Bangladesh, is projected to see declines in the number of twin births because fertility is below replacement and fewer women will give birth.
Recommendations
- Train frontline health workers to monitor and care for twins to improve local birth outcomes.
- Establish a twin registry to track health and development, support policy, and advance research on survival and biological aspects of twinning.
