Key Insights
Why have multiple births become more common over time?
The rise in multiple births is primarily due to the use of fertility drugs, which increase the release of multiple eggs and their fertilization. Additionally, improved medical care and infant formula have enhanced the survival rates of multiple births.
What are the two main types of twins?
The two main types of twins are fraternal (dizygotic) twins, resulting from two separate eggs being fertilized by two separate sperm, and identical (monozygotic) twins, resulting from a single fertilized egg splitting into two embryos.
Why are fraternal twins more common among the Yoruba people in West Africa?
The high rate of fraternal twins among the Yoruba people is thought to be due to their diet, particularly the consumption of yams containing phytoestrogens that stimulate the release of multiple eggs.
What is the rarest type of twin?
Sesquiseotic twins, also known as half-identical twins, are the rarest type. They result from a single egg being fertilized by two different sperm, followed by a series of rare events leading to two separate embryos sharing the same amniotic sac.
How have medical advancements impacted the survival of multiple births?
Medical advancements, including improved care for premature babies, regular use of cesarean sections, and developments in infant formula, have significantly increased the survival rates of multiple births, especially in extreme cases like quintuplets and beyond.
Chapters
- Multiple births have become more common over time, with a significant increase in twin births in the U.S. from 9.4 per thousand in 1980 to 16.7 per thousand in 2009.
- The primary reason for this increase is the use of fertility drugs, which result in the release of multiple eggs.
- The Yoruba people of West Africa have a particularly high rate of twin births, possibly due to their diet, which includes yams containing phytoestrogens.
Shownotes Transcript
