Age. According to the Office on Women's Health , women who are aged 30 years or older are more likely to conceive twins. The reason for this is that women of this age are more likely than younger women to release more than one egg during their reproductive cycle.
The quick answer to this question is that, in a twin pregnancy, it is the mother's genes that determine twins. First up, giving birth to identical twins is not genetic, but conceiving fraternal twins is. The mother may have the genetic trait of releasing two eggs in one menstrual cycle.
The notion that twins always skip a generation is also a myth. The illusion may have arisen because men who inherit the gene from their mothers are unaffected by it ( they do not ovulate), but can still pass it on to their daughters, who, in turn, will have an increased likelihood of conceiving twins.
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.
"Today, twins can usually be diagnosed as early as six to seven weeks into the pregnancy," he says.
The rate keeps rising for (naturally) two big reasons. More twins are being born now than ever before. Parents are increasingly using in-vitro fertilization and deciding to have children later in life. The twin rate could continue to go up as more nations push these factors higher.
Ivory Coast registered a rate of 24.9 twins for every 1,000 deliveries in the period 2010–15, according to a study of data from 135 countries by the University of Oxford's Christiaan Monden and his colleagues published in 2020.
Twins are more or less equally likely to be female or male. Contrary to popular belief, the incidence of twins doesn't skip generations.
Reasons for More Twin Births
Several factors have been identified as contributing to increased twinning. One study associated rising obesity rates with increases in twinning, citing that overweight or tall women are more likely to have twins. Women under age 25: 2% of births were a twin delivery.
Even if you are pregnant with twins, there's no guarantee you will produce hCG any sooner than if you were pregnant with one baby. But because your levels may be higher, it is possible to detect a pregnancy slightly earlier due to higher levels of hCG.
Are twins hereditary? Yes, some types of twins are hereditary, meaning that twins run in families. Heredity on the mother's side ups a couple's odds of conceiving fraternal twins. Fraternal twins are two babies from two different eggs that were released from the ovaries simultaneously.
With a twin pregnancy, your body makes high levels of pregnancy hormones. So morning sickness may come on earlier and stronger than if you were carrying a single baby. You may also have earlier and more intense symptoms from pregnancy, like swelling, heartburn, leg cramps, bladder discomfort, and sleep problems.
Factors that increase the chance of twins include: consuming high amounts of dairy foods, being over the age of 30, and conceiving while breastfeeding. Many fertility drugs including Clomid, Gonal-F, and Follistim also increase the odds of a twin pregnancy.
Your nausea and vomiting may be worse than ever: Morning sickness peaks around 9 or 10 weeks of pregnancy for many women. That's when levels of the pregnancy hormone human chorionic gonadotropin (hCG) are highest (morning sickness is thought to be linked to rises in hCG and estrogen).
Elevated Beta-hCG Levels
If you are using a regular pregnancy test (not the super-sensitive variety) and get an immediate positive (especially a very dark positive indicator) a few days before your period is due, there may be an increased chance that you are carrying twins.
Identical (i.e., monozygotic, or MZ) twins share 100 percent of their genes, whereas fraternal (i.e., dizygotic, or DZ) twins generally share only 50 percent of their genes.
According to Stanford, the likelihood of twins during any particular pregnancy comes from the mother, because, as they put it, "A father's genes can't make a woman release two eggs." If you're the woman who is trying to conceive though, it's not just your mom's genetics that matter.
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.
Home pregnancy test positive earlier than “normal”
If you get a positive test, especially a really dark positive, days before your period is even due, that may be one of the early signs of twins! The more babies you're carrying, the higher and faster your human chorionic gonadotropin hormone (hCG) rises.
Fraternal Twins: This type of twin set is the most common. This occurs when two different eggs are both fertilized by two different sperm and implant themselves into the uterine wall at the same time. Fraternal twins will both have a different amniotic sac and placenta.
Don t be surprised if you develop a bit of a 6 weeks pregnant belly. Although your 6 week embryo is still well down in your pelvis, some women, especially those who've been pregnant before, seem to show much earlier. General abdominal distention is usually the cause.
Now an international research group has found that twin mothers are not actually more fertile than other women. On the contrary, when a woman gives birth several times, the chances increase that at least one of these births will be a twin birth. Twin mothers aren't supermothers, but have been given more chances."
What is the likelihood of having more than one set of twins? If existing twins are identical the chance of having another set is the same as most women, about 1 in 250. If the twins are non- identical the chances of having twins again are much higher.