Global fertility rates are declining, yet multiple births—like twins and triplets—are at an all-time high. This unprecedented trend marks a significant shift in human reproduction. It is driven by factors like older maternal age. Increased use of fertility treatments also plays a role.
Multiple births are a natural part of human reproduction, though less common than single pregnancies. About one in every 60 pregnancies results in twins, triplets, or higher-order multiples.
BIRTH TRENDS OVER TIME
The Baby Boom Era (1940s–1960s)
During the post-war baby boom, multiple birth rates in England and Wales remained steady at 12–13 per 1,000 pregnancies. With an average maternal age of 26, the likelihood of multiple births was relatively low.
Decline in Larger Families (1970s–1980s)
Economic challenges and widespread access to family planning led to smaller family sizes. In the 1980s, multiple birth rates decreased significantly. They dropped to about 10 per 1,000 maternities. This change coincided with an average maternal age of 26.
RISE OF FERTILITY TREATMENTS
The 1990s and 2000s saw a resurgence in multiple births, fueled by two key factors:
- Older Maternal Age: Women began having children later, increasing the natural likelihood of multiples.
- Fertility Treatments: Early IVF practices often transferred multiple embryos to improve pregnancy success rates, significantly boosting multiple birth rates.
In the 1990s, 28% of pregnancies from fertility treatments resulted in multiples, compared to the natural rate of 1–2%.
THE “ONE AT A TIME” CAMPAIGN
The UK aimed to address concerns over premature births and associated risks. They launched the “One at a Time” campaign. This campaign advocates for single embryo transfers. By 2023, only 4% of fertility treatment pregnancies resulted in multiples.
CURRENT AND FUTURE TRENDS
Recent Statistics
- The UK multiple birth rate peaked at over 16 per 1,000 pregnancies in the mid-2010s.
- As of 2023, the rate stands at 14.4 per 1,000 maternities.
Fertility Tourism
The rising cost of fertility treatments and limited NHS funding have led some couples to seek care abroad. Practices around multi-embryo transfers vary across countries, potentially influencing higher multiple birth rates in fertility tourism hotspots.
CHALLENGES OF RAISING MULTIPLES
While multiple births bring joy to families, they also come with significant challenges:
- Health Risks: Twins face double the stillbirth risk compared to singletons. Preterm births are common in 60% of twins. Nearly all higher-order multiples experience preterm births.
- Financial Strain: Raising multiples costs at least £20,000 more than two singletons born consecutively.
- Emotional Toll: Parents often experience heightened anxiety, compounded by the need for neonatal care and practical support.
A NEED FOR ADAPTATION IN MATERNITY CARE
The rise in multiple births demands a shift in how maternity and early years care are structured. As fertility rates decline globally, the proportion of multiple births may continue to rise, reshaping family dynamics and healthcare needs.
HOW DO MULTIPLE BIRTHS OCCUR?
- Twins: Formed when either two separate eggs are fertilized (fraternal) or a single fertilized egg splits (identical).
- Hyper-ovulation: Occurs when more than one egg is released during a cycle, increasing the likelihood of multiples.
Hyper-ovulation becomes more likely as women approach perimenopause, leading to an increase in natural multiple births in older mothers.
