Twin Pregnancy - What You Should Know!

What is a twin pregnancy?

A twin pregnancy is a pregnancy in which, instead of just one child, two children mature in the uterus at the same time. Twins can share an amniotic sac and placenta, or develop both on their own. This depends on whether the children are identical or dizygoti, i.e. whether they originated from the same egg cell.

Twin pregnancies are much less common than pregnancies with just one baby. Some risks are slightly increased during a twin pregnancy, which is why they are more often high-risk pregnancies.

You can find more about high-risk pregnancy at: High risk pregnancy

When does a twin pregnancy occur?

There are a few different causes of twin pregnancy.
The first cause is that an egg cell accidentally matures in both ovaries instead of - as usual - only on one side. Both egg cells can then be fertilized and mature into a child on their own.
The second reason is that in the early stages of division the cells move apart and two children develop from one egg cell.
Another possible cause of twin or multiple pregnancies is artificial insemination, as several egg cells are always used to increase the chance of a successful pregnancy.
A very rare case is that a woman has two wombs and so two children can grow up at the same time.

Probability of twin pregnancy

Nature actually foresees pregnancies with single children in humans and therefore twins are relatively rare. About every 80th pregnancies are twins, with about one-third of those twins producing identical children. The number of unreported cases in twin pregnancies is relatively high, as many embryos die in the first few weeks of pregnancy and only one child matures. The frequency of twin births is increasing as women become more and more late pregnant and also take hormonal support more often.

Identical twins

At the beginning of a pregnancy, the fertilized egg cell divides several times and thus doubles the number of cells.
With this division, the cells are all still very variable and could theoretically each grow into a child. If the clumps of cells drift too far apart in these early phases, two children emerge.
Depending on the point in time of this division, the children can share an amniotic sac or a placenta or train themselves. These twins consist of the same egg cell and the same sperm and therefore have identical genetic information. Identical twins are always the same sex and look very similar later on.
About 30 percent of all pairs of twins are identical twins. The distinction can be particularly well examined during pregnancy between the eighth and the 12th week of pregnancy. Identical twins require closer watch during pregnancy as the incidence of complications is greater.
However, the genetic information also codes for hereditary diseases. So if a child is affected, the sibling will also have the disease.
In very rare cases, the twins separate so late that they do not separate completely from each other, but remain connected somewhere as Siamese twins.

Dizygotic twins

Normally, one egg cell matures in a woman in every cycle, i.e. every 28 days. This can then be fertilized and develop into a child. In some cases, however, egg cells mature in both ovaries and double ovulation occurs. Each egg cell is fertilized by a different sperm and two children are born.
The children have different genes and are no more similar than siblings of different ages. Every child has their own amniotic sac and also their own mother cake. This makes the children less prone to certain complications. An example of this is that the supply of the children is independent of each other and thus one child cannot withdraw nutrients from the other child.
Even if a child becomes seriously ill, the sibling does not have to be affected. About two in three twin pregnancies are dizygoti twins. The best way to determine whether twins are dizygoti is before the 16th week of pregnancy. In the case of children of different sexes, it can still be said with certainty later in pregnancy that the twins are dizygoti.

These are the signs of a twin pregnancy

Especially in early pregnancy, a twin pregnancy does not differ from a pregnancy with a single child.
The finding is often a chance finding during one of the first preventive examinations during pregnancy. Only in late pregnancy do some differences arise, such as a possibly larger belly. A clue for a twin pregnancy can be that there has been an increased number of twin births in the family or that the pregnancy is based on artificial insemination.

This is how the belly changes in a twin pregnancy

During pregnancy, the mother's body goes through many changes.
At the beginning of pregnancy, the belly of a twin mother is no different from the belly of a woman who is only expecting one child. From around the 16th week the children have a size that stretches the uterus and the pregnancy belly becomes visible. The mother's organs now have to be moved because the twins need space in the abdomen. This happens a little earlier and to a greater extent in twins than in other pregnancies.
From the 24th week of pregnancy, the baby bump can no longer be hidden. This is also about four weeks earlier than for mothers who are just expecting one child. Since two children need more space than a single child, the baby bump grows stronger and faster. This leads to increased stretch marks and increased pressure on the mother's bladder. The regression after the birth can also take a little longer than after a single birth, as the tissue is stretched significantly more.

Since it is mainlystretch marks can occur in twin pregnancies, you may also be interested in the following pages:

  • Prevent stretch marks
  • Can you have stretch marks removed?

Associated Risks

Basically, pregnancy is not a disease, but a natural occurrence. However, pregnancies can be associated with complications, and complications are more common in twin pregnancies.
For example, twins are at greater risk of premature birth than a single child. A few weeks are not critical here, but very early births are also more common in twins. These children can then suffer from immature lungs and other developmental disorders.
Twin transfusion syndrome can also occur in a twin pregnancy. The children's cycles are linked and one child becomes the donor and the other child the recipient. This results in a different supply and an uneven growth of the children. This can lead to the death of the underserved child.
In principle, growth retardation can also occur in twins because the mother has to provide the nutrients for two children.
There may also be additional risks during childbirth, as the children assume a different position in the mother's womb than an individual child. This means that twin births are carried out more often than caesarean sections. All other risks are similar to those for individual children and can only be increased in frequency.

For detailed information on the complications, see: Pregnancy complications - everything about this topic!

What happens if a child dies during pregnancy?

Nowadays, twin pregnancy can be diagnosed very early. This can be a blessing and a curse. The mothers have to be prepared for the fact that not both children will survive, since in many twin pregnancies one embryo dies in the first weeks of pregnancy and only one child grows up.
A twin who dies at this early stage does not mean a higher risk for the mother or the living twin.
However, if a child dies later in pregnancy: this does pose a risk. The deceased twin usually has to be taken out or the mother loses the child on her own divided amniotic sac the second child often has to be born prematurely.

Further information on this topic can be found at: Miscarriage

Duration of a twin pregnancy

A normal pregnancy lasts 40 weeks from the first day of your last menstrual period. This is no different with twin pregnancies either, as the time it takes for a child to grow does not change. Pregnancies that last less than 37 weeks mean premature birth.
Twins are much more likely to give birth prematurely, as the space in the mother's womb is simply limited and the birth is initiated sooner. In most cases, however, the pregnancies are only three to four weeks shorter, which is not critical for the children, as the important organ maturation has already taken place.

Employment ban in the event of a twin pregnancy

Although the compatibility of family and work and thus also of pregnancy and work is increasing, there are some professions that a pregnant woman cannot and is not allowed to pursue.
Since twin pregnancies often run as high-risk pregnancies, the restrictions are even greater here.
A general ban on employment, regardless of whether it is a normal pregnancy or a high-risk pregnancy, is anchored in the Maternity Protection Act. This includes the fact that the expectant mother may not lift more than five kilograms and may not stand for more than four hours in late pregnancy. Dangers to mother and child in the form of occupational and infectious diseases, for example in the laboratory, must also be prevented.
A partial professional ban states that women are only not allowed to do certain activities. A twin pregnancy can be a reason for an individual ban on employment. Twins are more likely to be born prematurely and the mothers have to take more care of themselves, which is why many expectant twin mothers have to stay away from work at the end of the pregnancy even before the absolute ban on employment. A medical certificate is required for an individual prohibition of employment and a certificate from a midwife is not sufficient.

You can find more detailed information on this topic at: Employment prohibition during pregnancy