How are multiple pregnancies classified?

If the number of pregnancies settled in the uterus is more than one, it is called a multiple pregnancy. The most common is twin pregnancy. Although it varies according to ethnicity, approximately 1-3% of live births are twin pregnancies. On the other hand, 97% of multiple pregnancies are twin pregnancies. Twin pregnancies are divided into two depending on whether they originate from a single egg or fraternal egg. Triplet pregnancies are usually the complications of assisted reproductive techniques. It is very rare and has a frequency of approximately 1000-2000 pregnancies.

The most important examination of multiple pregnancies is the first trimester examination.

In the first trimester examination, the number of pregnancies, location and risks are determined. In particular, this examination distinguishes between identical fraternal twins. Preferably, this examination should be performed by a perinatologist. In twin pregnancies, the most important is chorionicity, that is, to confirm whether it is caused by a single egg or a double egg. Identical twins, on the other hand, are the type of twins that should be followed by perinatology specialists.

In this article, we have compiled for you what you need to know about risk factors and risk management related to multiple pregnancy. You can find the details on the subject in the continuation of our article.

What Are the Symptoms of Multiple Pregnancy?

In cases of multiple pregnancy, the following symptoms may occur:

• Increased Uterine Size: In cases of multiple pregnancy, the uterus of the expectant mother may tend to grow faster and more. A larger abdomen than the normally expected gestational size may be observed.

• High HCG Levels: In multiple pregnancies, the human chorionic gonadotropin (hCG) levels in the blood of the expectant mother will be higher than normal. Even before the gestational sac is seen, this is a good indicator.

• Severe Morning Sickness: Morning sickness may be more intense in multiple pregnancies and is usually more severe than in singleton pregnancies.

• Multiple Fetal Movements: In multiple pregnancies, the expectant mother can feel the movement of more than one baby. Because there is more than one baby, fetal movements may be more frequent and more intense.

What Are the Risks of Multiple Pregnancy?

In cases of multiple pregnancies, some additional risks are seen compared to singleton pregnancies, and some complications may occur more frequently. We can list some of the risks frequently encountered in multiple pregnancies as follows:

• Vanishing Twin: This is very common in twins, and this is when the pregnancy starts as a twin and continues as a singleton. It constitutes the outcome of pregnancies that start twining at a rate of about 10-30%.

• Growth retardation and incompatible development: The rate of growth retardation is more common in twin pregnancies than in singleton pregnancies. In addition, if there is a difference of more than 20% between the estimated weights of the two fetuses, it means that there is discordant development between twins. These conditions should be managed by a perinatologist.

• Premature Birth: The risk of preterm birth is higher in multiple pregnancies and approximately more than 50% of twins are born before 37 weeks.

• Low Birth Weight: In second pregnancy, babies grow as singletons in the mother’s womb until 28 weeks, but then they stay smaller because their place is narrowed.

• Gestational Diabetes: The risk of gestational diabetes, that is, gestational diabetes, increases in multiple pregnancies. Both the excess weight gained and the pregnancy hormones have a great effect on this situation.

• Preeclampsia: Preeclampsia is also known as gestational hypertension or pregnancy poisoning. While this risk is about 5-6% in singleton pregnancies, it goes up to 13% in twin pregnancies.

How to screen for Down Syndrome in Multiple Pregnancy?

Screening for Down syndrome in twin pregnancies can be done in the same way as in singleton pregnancies. We have covered the screening strategies for Down syndrome in pregnancy in detail under another heading. We will now briefly summarize.

• In twin pregnancies, as in singleton pregnancies, a detailed ultrasound is performed between 11-14 weeks. If anomaly is not detected afterward, double test or combined test can be performed.

• Fetal DNA testing in twin pregnancies can also be performed with a similar success rate to singletons.

• Triple and quadruple test can be done in pregnant women who missed the time of the double test.

• It should be noted that the double test is a more successful test than the triple and quadruple test.

• The only screening that can be done in triplet and higher pregnancies is ultrasound examination.

• Diagnostic tests, namely CVS, Amniocentesis and Cordocentesis, are performed in pregnant women whose screening test is risky, just as in singleton pregnancies.

In all matters such as multiple pregnancy risks, follow-up management, Prof. Dr. You can contact Ali Ekiz.