As a parent of twins, I'm pretty sure that you know the answer to the question “which twin is older?” It is, of course, the child that was born first.
In addition, previous studies have shown that first-born twins are, on average, taller and heavier than second-born twins until adolescence (Silventoinen et al., 2007; Pietiläinen et al., 2002).
Birth Order and Twins
The babies' order of birth is determined by their position in the womb, which can change throughout pregnancy. In some cases, which baby is born first depends on how the mother delivers; the order might be switched if the mother had a Cesarean section rather than vaginal delivery.
On September 1, sisters Umeno Sumiyama and Koume Kodama turned 107 years and 300 days old, officially breaking the record for the world's oldest living identical twins. The Japanese siblings are also the oldest identical twins to have ever lived.
As a parent of twins, I'm pretty sure that you know the answer to the question “which twin is older?” It is, of course, the child that was born first.
Yes, you read that right. Twins (non-identical) can be born at completely different times, sometimes even years apart.
Fraternal twins live longer than singletons and identical twins longer still. Male identical twins on average, saw the most benefit. The rarity of twins has inspired many myths about them.
Monoamniotic-monochorionic Twins
This is the rarest type of twin, and it means a riskier pregnancy as the babies can get tangled in their own umbilical cords. If you have monoamniotic-monochorionic twins, your healthcare provider will monitor your pregnancy closely.
However, for a given pregnancy, only the mother's genetics matter. Fraternal twins happen when two eggs are simultaneously fertilized instead of just one. A father's genes can't make a woman release two eggs.
However, since only women ovulate, the connection is only valid on the mother's side of the family. While men can carry the gene and pass it on to their daughters, a family history of twins doesn't make them any more likely to have twins themselves.
The likelihood of conceiving twins is a complex trait, meaning that it is affected by multiple genetic and environmental factors, depending on the type of twins. The two types of twins are classified as monozygotic and dizygotic.
The fetus with more blood flow is called the recipient twin, and the fetus with less is called the donor twin. Because the donor twin has less blood flow, this baby grows slower and is smaller.
Her brother, Adrial Luka Nadarajah, joined her 23 minutes later, weighing not quite 15 ounces. According to Guinness World Records, the pair are both the most premature and lightest twins ever born.
The DNA of monozygotic twins tends not to be 100% identical, and epigenetic and environmental differences further widen the gap between twin pairs. It's not nature or nurture; it's a complex interaction between our genes, our environment, and our epigenetic markers that shape who we are and what illnesses befall us.
In 99.9% of cases boy/girl twins are non-identical. However, in some extremely rare cases resulting from a genetic mutation, identical twins from an egg and sperm which began as male (XY) can develop into a male / female pair.
Longer lives
When analyzing the data by gender, the researchers found that female identical twins lived, on average, about 63.4 years, whereas female fraternal twins lived about 61.4 years and the general Danish female population lived about 58.8 years, Sharrow said.
According to Enbom, the incidence of twin pregnancies with single fetal demise ranges from 0.5% to 6.8% [6,7]. Intrauterine single fetal death can occur at any gestational age. If this event happens in the first trimester of the pregnancy, the surviving twin will most likely develop without further consequences.
Identical twins reported similar levels of happiness, while fraternal twins exhibited greater variation in their reported sense of well-being. These results were found in families of twins raised together and extended with twins reared apart.
Can twins have different fathers? In rare cases, fraternal twins can be born from two different fathers in a phenomenon called heteropaternal superfecundation. Although uncommon, rare cases have been documented where a woman is pregnant by two different men at the same time.
Babies that are born close to midnight may arrive on different days. For example, Twin A may be born at 11:59 pm on one day while Twin B doesn't make an appearance until 12:01 am, which would be the next day.
They come from the same fertilized egg and share the same genetic blueprint. To a standard DNA test, they are indistinguishable. But any forensics expert will tell you that there is at least one surefire way to tell them apart: identical twins do not have matching fingerprints.