To form identical or monozygotic twins, one fertilised egg (ovum) splits and develops into two babies with exactly the same genetic information. To form fraternal or dizygotic twins, two eggs (ova) are fertilised by two sperm and produce two genetically unique children.
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.
The hardest thing about having twins is…
“Managing the movement of two babies. Carrying them both up and down the stairs, getting them into the car, etc.” —Simeon R. “Often having to make one baby wait!” —Catharine D. “Being outnumbered—the logistics of two on one is definitely the hardest.
Just like singleton babies, twins can sometimes get super-active in the womb. But not to worry — there's no real threat from it! Babies can kick or even hit each other (yes, really) in utero, but the good news is the amniotic fluid acts as a cushion to protect them from actually getting hurt by any of it.
Being a twin has its benefits—tricking people, having a lifelong companion, sharing clothes—but it also has downsides. Many twins struggle to cultivate their own identities, while being so similar to one another. And that struggle lasts a lifetime, according to a recent study.
Once the babies are large enough to stay in one position in the womb, the twin lowest in the uterus is known as Baby A and the one furthest from there is Baby B, according to the Stanford Medicine News Center. In the majority of vaginal births, Baby A is born first.
Twins are more likely to be born early, often before 38 weeks, so it's important to understand your birth options. Less than half of all twin pregnancies last beyond 37 weeks.
Two babies are twins and three are triplets.
It is estimated that 1 in 250 natural pregnancies will naturally result in twins. While twin pregnancies can happen by chance, there are some factors that may increase your odds of having two babies at the same time.
The Yorubas believe twins bring good luck and riches, though many do not appear to remember this when their wives give birth to twins. People believe that, depending on how they are treated, twins can bring either fortune or misfortune to their families and communities.
Twins Become Aware of Each Other in the Utero
According to multiple studies that include 3D ultrasounds, twins start to reach out and touch each other in the womb starting at about 14 weeks. At about 18 weeks, they touch each other more often.
According to The American Society for Reproductive Medicine, women who are fraternal twins have a 1 in 60 chance of having twins, and men who are fraternal twins have a 1 in 125 chance of fathering twins. It was previously believed that identical (monozygotic) twins were random — not genetic.
The concept of fertility symbolized by twins corroborated by the study of more than a dozen dreams-is confirmed by mythology. The most obvious meaning suggested by twins is fertility, although it seems to be considered a bad omen.
Everyone has the same chance of having identical twins: about 1 in 250. Identical twins do not run in families. But there are some factors that make having non-identical twins more likely: non-identical twins are more common in some ethnic groups, with the highest rate among Nigerians and the lowest among Japanese.
Medically, this 7-year defect is very rare. Twins are typically born with a bit of a delay — a few minutes to a few hours. Some even have separate birthdays, due to being born just before and just after midnight. The Zeitgest girls were not only born 7 years apart, but Ms.
Twins not only have a bestie from birth — they also live longer than singletons. And those two factors may be related, according to new University of Washington research.
Both results were statistically significant. Moms of twins also were older at the time of their last birth. The age at last birth averaged 39.7 years for women born before 1870, and 36.2 years for women born during 1870-1899. Moms of twins had their last births 4.8 months later and 14 months later, respectively.
As expected, first-born twins had greater birth weight than second-born twins. With respect to height, first-born twins were slightly taller than second-born twins in childhood.
Quite simply, in early pregnancy, the fetus contained in the gestational sac closest to the maternal cervix was designated as Twin 1, and the relative orientation of the fetuses to each other was then defined as being either lateral (left/right) or vertical (top/bottom).
Twins on the average seem to have lower IQs than singletons. The best estimate for this group difference is 4.2 IQ points (less than one-third of a standard deviation), with a great divide between study outcomes of less vs more recent birth cohorts (5.1 vs 0.5 IQ points, respectively).
“Having twins is not twice as hard—it's exponentially more difficult,” says Natalie Diaz, author of What To Do When You're Having Two and CEO of Twiniversity, a global support network for parents of twins.
Personality differences.
If one twin is more outgoing and the other more shy, the shy twin may develop speech and language skills at a slower rate. One twin/multiple is the “spokesperson.” We see this a lot too with children who have older siblings who “speak” for them.
Twins are competitive with each other and/or jealous of one another because of their unique and deep attachment, which creates judgments. This rivalry is based on the reality that twins measure themselves against each other from an early age.