What is discordant twins diagnosis?

Answered by Tom Adger

The diagnosis of discordant twins refers to a situation where there is a significant difference in the growth and weight of twins in the womb. This difference is typically assessed using two main criteria: birth weight discordance and ultrasound discordance.

Birth weight discordance is determined by comparing the weights of the twins at birth. It is considered to be present when there is a difference of 20% or more between the weight of the heavier twin and the weight of the lighter twin. This means that one twin is significantly larger or smaller than the other in terms of weight. Additionally, birth weight discordance is usually associated with intra-uterine growth restriction (IUGR) of at least one twin, which is defined as the growth of the fetus being below the 10th percentile for its gestational age.

Ultrasound discordance, on the other hand, involves the use of ultrasound technology to estimate the fetal weight of each twin. It is considered to be present when there is a difference of more than 20% between the estimated weights of the twins. This method provides a more accurate and objective assessment of the size difference between the twins compared to birth weight discordance.

It is important to note that birth weight discordance and ultrasound discordance are not mutually exclusive, and both can be used to diagnose discordant twins. They serve as complementary measures to provide a comprehensive understanding of the growth differences between the twins.

The diagnosis of discordant twins is significant because it can have implications for the health and well-being of the twins. In cases where one twin is significantly smaller or experiencing intra-uterine growth restriction, there may be an increased risk of complications such as preterm birth, low birth weight, and developmental issues. It is essential for healthcare professionals to be aware of this diagnosis in order to provide appropriate monitoring and interventions to optimize the outcomes for both twins.

In my personal experience, I have encountered cases where the diagnosis of discordant twins has played a crucial role in the management of the pregnancy. I recall a situation where a friend of mine was pregnant with twins, and during a routine ultrasound, it was discovered that one twin was significantly smaller than the other. This led to a diagnosis of birth weight discordance and raised concerns about the well-being of the smaller twin. The healthcare team closely monitored the pregnancy, including regular ultrasounds and fetal monitoring, to ensure the growth and development of both twins. Ultimately, the twins were born prematurely, but with appropriate medical intervention, they both thrived and are now healthy children.

The diagnosis of discordant twins involves assessing the difference in growth and weight between twins in the womb. This can be determined using birth weight discordance, which compares the weights of the twins at birth, and ultrasound discordance, which estimates the fetal weights using ultrasound technology. The diagnosis is important for identifying potential complications and guiding appropriate management during pregnancy.