Twin Pregnancy: Early Ultrasound & What To Expect
Are you curious about the fascinating journey of a multiple pregnancy? Discovering you're carrying twins or more is a life-altering event, filled with both excitement and a heightened need for careful monitoring.
In the realm of prenatal care, the initial ultrasound holds significant importance, particularly when multiple pregnancies are suspected. This initial scan allows healthcare professionals to assess vital aspects of each developing embryo. The first key element involves checking the cardiac activity of each embryo, confirming their heartbeats. Simultaneously, the size of the embryos is meticulously measured to ascertain whether their development aligns with the gestational age, calculated from the woman's last menstrual period. Furthermore, the type of twin gestation is categorized, determining the number of embryos and the number of placentas present. This crucial information forms the foundation for understanding the unique characteristics and potential challenges of the pregnancy.
Early detection of a multiple pregnancy is key to providing appropriate care. Elevated levels of human chorionic gonadotropin (hCG) in the early stages of pregnancy can be an indicator of a twin pregnancy. However, this alone is not a definitive method. Specific weeks of gestation are crucial for confirmation.
Multiple studies have shown that the majority of twin pregnancies are confirmed between the seventh and tenth weeks of gestation. During an ultrasound, the gestational sacs, which envelop the developing embryos, may be visible. In identical twin pregnancies, there might be a single gestational sac. The size of these sacs is remarkably small, measuring around 2 mm. This early visualization, although subtle, provides the first glimpse into the possibility of a multiple pregnancy.
The ultrasound is an invaluable tool for differentiating between identical and fraternal twins, accomplished by examining the placenta and amniotic sacs. In identical twins, a single placenta and a single amniotic sac will be present, enveloping both fetuses. Conversely, in fraternal twins, each fetus has its own placenta and amniotic sac. This distinction is crucial for the subsequent monitoring and management of the pregnancy, as it influences the risks and complications associated with each type of twin gestation.
Interestingly, while not a scientific sign, many mothers of twins report experiencing an intuition or premonition that they were expecting more than one baby. This feeling often manifests as an internal knowing or a strong conviction that the pregnancy is multiple. It's a testament to the profound connection mothers have with their developing babies, and it underscores the emotional journey that accompanies the anticipation of multiple births.
The membrane that separates twins can be quite thick. The central point of color observed in two-dimensional (2D) ultrasounds corresponds to the dividing membrane between twins. The 3D image confirms this definitively. Additionally, the type of twin gestation can influence the risks involved. Monochorionic twins, who share a placenta, face a higher risk of neurological alterations, intrauterine growth restriction, discordant twins (where one twin grows more than the other), and even the unfortunate possibility of one twin's demise within the womb. The majority of these intrauterine deaths occur before 24 weeks of gestation. Consequently, careful monitoring and early intervention are paramount in ensuring the best possible outcomes for both the mother and the babies.
The increase in twin pregnancies has been significantly linked to assisted reproductive technologies. Between 2% and 3% of pregnancies in Spain involve twins. This increase is directly associated with the use of assisted reproduction techniques in recent decades.
Even though it's not a scientific signal to determine if twins are present before an ultrasound, many mothers of twins claim to have had an intuition or premonition that they were expecting more than one baby. This sensation can manifest as an inner knowing or a strong conviction that it is a multiple pregnancy.For this reason, to reduce risks and to identify these problems as soon as possible if they occur, we perform ultrasounds more frequently. Between 2 and 3 percent of pregnancies in Spain correspond to twin pregnancies, a rate that has increased in recent decades due to assisted reproduction techniques. Seven out of ten cases are dizygotic twins (known as fraternal twins, that is...Despite its limitations, ultrasound is a technique that provides a great deal of information about a pregnancy. As we have seen, although it is not common, it is possible to have twins that are not seen in the first ultrasound, that is, to have a hidden fetus during the first months of pregnancy.
Weight gain during pregnancy is another common symptom of twins or multiple pregnancy. According to the National Academy of Sciences of the United States, the pregnant woman usually increases 0.75 grams per week and 16 to 20 kilos in total. A third type of multiple pregnancy occurs when there are more than two fetuses, which can be a mixture of twins or Siamese twins, this can lead to the birth of three babies or more. In this case, having two gestational sacs of different sizes in the pregnancy suggests a twin gestation. However, in cases of independent sacs, each fetus has its own amniotic sac and its own placenta. This means that the twins are completely separated from each other, both physically and in terms of their supply of oxygen and nutrients. Each fetus develops independently, without affecting the other.
Babies who share a sac also have a higher likelihood of complications. The placenta in monochorionic twins presents irregular vascular connections which, under pathological conditions, can compromise the supply of nutrients for fetal growth and the oxygenation of one or both twins. This determination is very important to assess the risk of multiple pregnancy and how often we will be monitored. However, out there everyone associates pregnancy = 9 months and here comes the mess. Because, for practicality, we tend to count lunar months, that is, months of four weeks. And according to this count, you would now be 12 weeks / 4 = 3 months. However, this is not entirely accurate. When a woman is pregnant with twins, one of the biggest concerns that arise in parents is the good development of the fetuses during gestation. Despite the fact that in 70% of cases it occurs in a normal way, there are 30% of them in which complications appear for one or both babies. Twin pregnancy is considered "at risk." why is there a greater risk
Each of the babies is with their heads in one direction, as we can visualize on the ultrasound. One of the twins moves at the end of the ultrasound images while his brother rests.
| Aspect | Details |
|---|---|
| Type of Gestation | Multiple, typically twins, but can include triplets or more. |
| Confirmation Period | Typically confirmed between the 7th and 10th week of gestation. |
| Diagnostic Tools | Ultrasound scans are the primary method of confirming multiple pregnancies. |
| Initial Assessment | The first ultrasound examines the cardiac activity of each embryo and the size of the same with last menstrual period. |
| Differentiating Twins | Ultrasound determines if twins are identical (monochorionic) or fraternal (dichorionic) based on the placenta and amniotic sacs. |
| Risks & Complications | Monochorionic twins (sharing a placenta) face higher risks of neurological issues, growth restriction, discordance, and potential fetal death. |
| Gestational Sacs | In early scans, the presence and number of gestational sacs provide initial clues. |
| Maternal Intuition | Many mothers report a strong intuition or premonition of a multiple pregnancy before confirmation. |
| Incidence Rate | Between 2% and 3% of pregnancies in Spain are multiple gestations; the rate has increased due to assisted reproduction. |
| Weight Gain | Increased weight gain is a common symptom of twin pregnancies. |
| Fetal Development | Fetal development requires careful monitoring and frequent ultrasound examinations to track growth and detect any potential complications. |
| Early Signs | Higher-than-expected hCG levels in early pregnancy can suggest the possibility of twins. |
Further research and information regarding multiple pregnancies and related topics can be found at the American College of Obstetricians and Gynecologists (ACOG) website.
