Asian Americans and Native Americans have the lowest rates for twins. White people assigned female at birth have the highest rate of higher-order multiple births (triplets or more). This is especially true for those older than 35.
Race – African-American women are more likely to have twins than any other race. Asian and Native Americans have the lowest twinning rates. Caucasian women, especially those over age 35, have the highest rate of higher-order multiple births (triplets or more).
Race – African women have the highest incidence of twins, while Asian women have the lowest. Assisted reproductive techniques – many procedures rely on stimulating the ovaries with fertility drugs to produce eggs and, often, several eggs are released per ovulation.
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.
This belief is based on the assumption that twinning is genetic and runs in families. However, if that was truly the case—if there was a twin gene—then twins would occur with predictable frequency in those families that carry the gene. There is no concrete scientific evidence that suggests twins skip a generation.
Women older than 30 have a greater chance of multiple conception. Many women today are waiting to have children until later in life. They may have twins as a result.
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.
Researchers analysed records from more than 100 countries and found a substantial rise in twin birthrates since the 1980s, with one in 42 people now born a twin, equivalent to 1.6 million children a year. According to the study, the global twin birthrate has risen by one-third, on average, over the past 40 years.
Rate of twin births in the U.S. in 2020 and 2021, by month
In 2021, the month with the highest rate of twin births in the United States was July with almost 33 twin births per 1,000 total births.
The twinning rate in Asia and Latin America, on the other hand, is very low: often less than 8 per 1000 births and almost always less than 10 per 1000 births.
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.
Twin birth rates declined among mothers aged 30 and over, with the largest declines among older mothers aged 40 and over. The twinning rate dropped 7% among non-Hispanic white mothers from 2014 to 2018 (34.3 in 2018), but was essentially unchanged among non-Hispanic black (40.5) and Hispanic (24.4) mothers.
The central African country of Benin has the highest national average of twinning, with a whopping 27.9 twins per 1,000 births, the researchers added.
Most sets of Twins
The first wife (died ante 1770), of Feodor Vassilyev (b. 1707–c. 1782), a peasant from Shuya, Russia, gave birth to 16 sets of twins. Barbara Zulu of Barberton, South Africa bore 3 sets of girls and 3 mixed sets in seven years (1967–73).
Identical twins are almost always the same sex, although there are some rare exceptions to this rule. Because identical twins occur when a single fertilized egg splits and forms two embryos, each embryo has the same chromosomes (usually, XX for girls or XY for boys). Remember that sex and gender are not the same.
When people refer to Irish twins, it's important to recognize that although the siblings are close in age, they are not actually twins. In other words, they were not born during the same gestational period. Calling them Irish twins is just an informal way of classifying siblings that are born close together.
The birth process is similar to giving birth to a single baby. If you're planning a vaginal birth, your health team may recommend that you have an epidural for pain relief.
A little more than half of twin pregnancies end in preterm delivery (before 37 weeks). While 40 weeks is the full gestation period of the average pregnancy, most twin pregnancies are delivered at approximately 36 weeks (range 32-38 weeks depending on the type of twin pregnancy).
While you are breastfeeding/chestfeeding, your level of luteinizing hormone (LH) and prolactin are higher. LH has a direct effect on ovulation while prolactin is a pregnancy hormone. This combination may increase the chances of conceiving twins while breastfeeding/chestfeeding.
Women over 35 have a higher chance of having fraternal twins or multiples because they have more FSH (follicle-stimulating hormone) compared to younger women. FSH is responsible for causing an egg to mature for ovulation every month.
One study estimated a woman can have around 15 pregnancies in a lifetime. And depending on how many babies she births for each pregnancy, she'd probably have around 15-30 children. But the "most prolific mother ever," according to Guinness World Records, was Mrs.
A twin pregnancy can often be detected in your first trimester by an ultrasound Opens a new window at 6 weeks or later. If your healthcare provider checks your hcG levels, a higher-than-normal level can be a sign of a twin pregnancy. But you'll need an ultrasound to confirm that it's really twins.
A woman gave birth to octuplets in California Monday after 30 weeks of pregnancy. The six boys and two girls ranged in weight from 1 pound, 8 ounces, to 3 pounds, 4 ounces. How many babies can fit inside a pregnant woman? There's no scientific limit, but the largest reported number of fetuses in one womb was 15.