Twins babies are equally as adorable as they are fascinating. In the USA, there are 133,155 twin births every year, while in Canada, there are 12,000 multiple births each year, according to the Vanier Institute. Certain fertility medications, such as Follistim, Gonal-F and Clomid, boost the likelihood of twin births (or triplet or quad births). Other variables which determine who has twins include (but are not limited to) family history, weight and BMI.
For example, women older than 30 are more likely to conceive twins, because they have higher levels of FSH (follicle stimulating hormone) than younger women. Follicles sometimes overreact to follicle stimulating hormone and release a couple of eggs, instead of just one.
Also, females with body mass index levels of 30 or higher are more likely to become pregnant with twins. Higher body fat levels mean higher levels of the hormone, estrogen, and this extra estrogen may cause the ovaries to release a couple of eggs, or even more, instead of single eggs.
Now that you know why some women have twins and others don't, it's time to share tons of amazing facts about twins.
20 Some Twins Create Their Own Languages
According to the Irishnews.com, twins frequently make up their own languages. In fact, forty percent of twins make up their own secret languages. This is a phenomenon that linguists refer to as "cryptophasia".
Twin babies rely on each other to build vocabularies. Usually, they stop using these private languages when they begin learning actual languages. A scientific study, Autonomous Languages of Twins, shows that the stuff that very young twins say to each other is definitely not gibberish.
Usually, twins change adult words that they've heard because they can't say them properly yet. The result is impossible for anyone but the twin babies (or scientific researchers) to understand.
19 Identical Twins Don't Have Identical Genes
The genes of identical twins are different. A lot of people mistakenly believe that twins have identical DNA, but a host of genetic mutations occur while twin fetuses develop. This means that hundreds of genetic mutations may trigger millions of differences in genes.
According to McGill.ca, the fact that twins don't have the same DNA helps to explain why a twin might get cancer, while the other remains well. It also explains why twins don't have the same fingerprints. The study that shows differences in twin DNA was presented at a meeting of The American Society of Human Genetics.
18 Twins May Have Different Dads
I have to confess, I didn't know this important fact about twins until I started researching this article. Twins can have different dads. It's happened in the past and will happen again. According to Irishnews.com, it's very rare for twins to have different fathers. In America, the odds of this happening are one in four hundred.
If a woman gets intimate with two partners within a short time frame, during her ovulation phase, it's possible that each male will fertilize a separate egg. There is a scientific term for this phenomenon and it's "heteropaternal superfecundation". Two percent of USA paternity suits involve superfecundation.
17 Twin Births Are More Common Nowadays
According to the Huffington Post, the twin birth rate is rising. In fact, in the USA, the twin birth rate has risen by seventy-six percent since the beginning of the 80s.
In 2009, one in thirty babies born was part of a pair. Back in 1980, the average was one in fifty-three. Experts believe that the uptick in twin births is linked with the fact that having babies at an older age is common these days. Moms over the age of thirty are more likely to conceive twins. Also, fertility treatments are now used by more women and these treatments do boost the odds of multiple births.
16 There is a "Twin Gene"
Some families have more than one set of twins or triplets. The reason for this is a scientific phenomenon known as "hyperovulation", according to the Huffington Post. Women who inherit a particular gene which triggers hyper-ovulation (the release of more than one egg while ovulating) will have a greater chance of conceiving non-identical twins. These types of twins are called fraternal twins.
Fraternal twins are conceived via a couple of separate eggs. The gene may be passed onto children, who may someday have twins of their own. There isn't a gene for identical twins. When men pass on the gene, their daughters may conceive and this means twins that skip one generation.
15 Twins May Be Born At Different Times
We expect twins to be born within a few minutes of one another, but some twins are actually born years apart, according to the Huffington Post. For example, Jody and Simon Blake have a five year old son and a two month old daughter. These kids are twins. Their parents utilized IVF due to fertility problems.
During the IVF process, a couple of eggs were placed in Jody's womb. Only one of them was successful and that led to the birth of their son. They froze the other egg and then had their daughter years afterward. Twins born years apart are still twins.
14 Twins Begin Bonding in the Womb
According to Scientificamerican.com, twins start to interact socially while they are in the womb. By the fourteenth week of gestation, twins in the womb will reach out for their siblings. This information is based on an ultrasonography study performed by researchers at the University of Parma and the University of Turin. The study tracked the movements of several pairs of twins.
If you're pregnant with twins, you'll be pleased to know that your developing fetuses are comforting each other in the womb. They're interacting and looking out for each other, from week fourteen and up. This helps to explain the very close bond between twins.
13 One Brazilian Town is "Twin Central"
If you ever find yourself in the Brazilian town, Candido Godoi, you'll be spending time in the globe's "twin capital". From the late 50s to 2008, eight percent of births in the region were twin births. This is a much higher average than the twin birth rate elsewhere in Brazil, which is one percent, according to the Huffington Post.
Why are there so many twin births in this town? Well, it's believed to be the product of extensive inbreeding. More women in the town carry the hyperovulation gene, which boosts the odds of twin births. Another hotbed for twin births is Baldwinsville, in New York State.
12 Fraternal and Identical Twins Aren't the Only Types of Twins
Most of us believe that there are a couple of types of twins - fraternal and identical. However, according to Mindblowing-facts.org, there are actually seven twin types.
Examples include "mirror image twins", who have mirror image features, such as birthmarks on opposite shoulders or hair whorls that run in contrasting directions, and "half-identical twins", who have half of their genetic material in common, via their mothers. The other half of their genes are not the same. Half-identical twins have elements of fraternal twins.
The other types of twins are mixed chromosome twins, superfetation twins, superfecundation twins, identical twins, and fraternal twins.
11 Moms Who Are Carrying Twins Have More Morning Sickness
According to Webmd.com, moms-to-be who are carrying twins may get hit with more intense morning sickness than pregnant women who aren't carrying twins. This is because women carrying twins have higher levels of HCG.
HCG is human chorionic gonadotropin. It triggers an array of unwanted symptoms, including vomiting and nausea, during the 1st trimester of pregnancy. However, the symptoms of morning sickness should ease by the twelfth to fourteenth week of pregnancy.
Moms-to-be who are carrying twins are also prone to back pain, insomnia, and heartburn. They should also watch out for symptoms of anemia, as they are more likely to become anemic while they're carrying twins.
10 Twins May Be Able to Read Each Other's Thoughts
According to The New York Times, twins may be mind-readers, at least, when it comes to their twin brothers or sisters. A pair of conjoined twins were found to have a shared neural bridge which gave them the capacity to read each other's thoughts.
Lots of parents of twins notice that their twins sense problems with their twin siblings. It's like twin ESP. Twins may also do similar actions, even when they are far apart and have no knowledge of what their twin brothers and sisters are doing. They also have a habit of speaking simultaneously or finishing each other's sentences.
9 Moms With Twins Tend to Live Longer
According to a study by researchers from the University of Utah, which was published at the Huffingtonpost., moms who've given birth to twins enjoy longer lifespans than moms who don't give birth to twins.
The study featured data about fifty-nine thousand moms who were born from 1800 to 1970. It's believed that Moms of twins are strong ladies who pass on their rugged genes to their twins. Apparently, twin pregnancies, childbirth, and baby care don't rob women of their strength. They remain healthy and alive for longer than other moms. So, don't be afraid if you find out that you're expecting twin babies!
8 Identical Twins May Look Less Alike Over Time
Identical twins are derived from one egg and look very much alike, according to Livescience. Sometimes, it's pretty tough to tell which one is which. However, they are not clones. Different variables may cause twins to look less alike as the years pass. Examples of some of these variables are chemical exposures and daily diets.
Effects which make twins less similar are referred to as epigenic effects. Epigenic effects may also cause twins to get diseases when their twin siblings remain healthy. Older twins are generally less alike than younger ones. Lifestyle and environment are the reasons why.
7 Twins increase the Chance of parents Getting Divorced
According to Inreuters.com, couples who have twins and are married have a higher likelihood of getting divorced than couples who don't have twins. Twins mean double the baby care and worry and this may put a strain on relationships.
With this in mind, moms-to-be who are pregnant with twins should create strong support systems, so that they can hand off the twins sometimes after they are born...and spend quality time with their spouses. Until the twin babies grow a bit older, it's safe to say that most parents of twins have a lot on their plates. Romance may often take a backseat to baby care.
6 Expectant Moms Should Gain 35-45 Pounds
According to the American Pregnancy Association, women carrying twins should gain between thirty-five and forty-five pounds. If you're carrying triplets, you're encouraged to gain between fifty and sixty pounds. In particular, women pregnant with twins should do their best to gain at least twenty-four pounds by week twenty-four of pregnancy as doing so decreases the odds of pre-term labors.
Weight gain in the earlier weeks and months of pregnancy also helps the placenta to develop. Proper placenta growth ensures that nutrients pass through to fetuses. Four to six pounds should be gained during trimester one. During trimesters two and three, the weight gain of one and a half pounds a week is recommended.
5 Twins Separated at Birth Often Long for Siblings
One interesting and true story about fraternal twins who were separated at birth shows that separated twins know that something important is missing in their lives.
When Meredith Ellen Harrington was separated from her fraternal twin, Meredith Grace Rittenhouse, she was adopted and so was her sister. By age two, according to the Huffington Post, Meredith Ellen told her mom and dad that she wished for a sister and felt lonely. When Meredith Grace reached age three, she told someone that she wanted to be a sister when she grew up. Eventually, the sisters were reunited, so this poignant story did have a happy ending.
4 A Special Diet Can Boost The Chances Of Twins
According to Herfamily.ie, women who want to become pregnant with twins should eat certain foods that will help them to achieve their goals. During 2006, a doctor named Gary Steinman discovered that women who ate animal products had a higher likelihood of having twins. Dairy products were particularly important.
To try and conceive twins, you may want to step up your consumption of cheese and milk. It's believed that the hormones used in the modern dairy supply boost the odds of women who consume a lot of dairy products having twins. Hormones are also used during the raising of livestock.
3 Twins Aren't Always the Same Race
According to Wstwinregistry.org, it is possible to have twins who are of different races. An array of genes are involved with racial differences and the science behind racial appearance is extremely complicated. There are fraternal twins who seem to be of different race and this may be due to heteropaternal superfecundation (different fathers) or due to one twin looking more like one parent.
Biracial couples may find that they have fraternal twins where one baby looks more like a particular race and the other baby looks to be of the other race. Basically, fraternal twins may look very different.
2 You Can Tell Twins Apart by Checking Their Belly Buttons
You probably know that belly buttons are actually scars that remain after umbilical cords are detached. Navels aren't the product of genetics. Identical twins may not have identical belly buttons, so moms who want to tell their twins apart should inspect their navels and look for differences.
Fingerprints will also be different, but they are a little harder for parents to check! Twins start out with the same fingerprints but end up with different ones, according to Rd.com. The fingerprints change during the time in the womb. Most parents eventually get the hang of telling very similar twins apart, just based on how they act.
1 Fetuses That Share the Same Wombs May Not Be Twins
According to Rd.com, a condition known as "superfetation" happens when an expectant mom has her period and a second embryo is formed. This condition is very rare, but it's real. Typically, the second conceived fetus will be a preemie, who is born ahead of time, and the fetus that is conceived first will be a full-term birth. However, there have been times when both babies were born at the same time.
As you can see, the science of twins is absolutely fascinating. There is so much to learn and more information about twins may be revealed in the foreseeable future.
References: Multiplesofamerica.org, Vanierinstitute.ca, Irishnews.com, McGill.ca, Irishnews.com, Huffingtonpost.ca, Huffingtonpost.ca, Huffingtonpost.ca, Scientificamerican.com, Huffingtonpost.ca, Mindblowing-facts.org, Webmd.com, Nytimes.com, Huffingtonpost.ca, Livescience.com, Inreuters.com, Americanpregnancy.org, Huffingtonpost.ca, Huffingtonpost.ca, Herfamily.ie, Wstwinregistry.org, Rd.com