The World of Pregnancy

Ultrasound during Pregnancy: Side Effects & Fetal Abnormalities

Maybe no other method of examination didn`t had so much impact on obstetrics as ultrasound did. Today there`s no way to supervise a pregnancy`s development without an ultrasound. This goes under the arsenal of obstetrics and gynecology. The major advantage of this method is the fact that isn`t harmful or painful in any way, and allows the possibility of obtaining information in real time.

Ultrasound during Pregnancy

Ultrasound: General Aspects

There are 2 ways to perform an ultrasound during pregnancy: transabdominal (on the patient`s abdomen) and endovaginal (through the vagina).

Being a method in which there aren`t any adverse effects, doesn`t use radiations, isn`t harmful and in which in most cases doesn`t need special training (such as sedation), an ultrasound can be repeated as many times as it`s needed and at any groups of patients, especially pregnant women. When these last ones are concerned, either there aren`t other methods that can be used due to adverse effects, either require a close collaboration with the doctor, which sometimes may be difficult.

From the necessity of studying anatomical structures as best possible, there are now different types of transducers (probes), some of them for studying structures that are located deeper, others for superficial structures, and other ones for anatomical cavities such as the vagina, rectum or esophagus.

The purpose of an ultrasound is to identify specific congenital abnormalities of the fetus and correctly evaluate his health.

Academic medical centers have sophisticated equipment of the latest technology and qualified medical personnel, which are able to detect around 80% from the fetal problems that can be identified by ultrasound.

In the last years, it has appeared numerous clinics with ultrasounds in which doctors more or less qualified are working, but don`t really guarantee quality results, being able to identify only up to 13% from fetal congenital abnormalities.

Ideally, ultrasounds should be performed by physicians or obstetricians, who are specialized doctors in methods of ultrasound, who have the large experience in how to interpret results, and who are able to ensure the identification of fetal abnormalities as soon as possible.

How Many Ultrasounds Are Done during Pregnancy?

There isn`t an exact number of ultrasounds that a pregnant woman needs to do. An additional ultrasound is indicated whenever an anomaly of the pregnancy is suspected. In reality, the first ultrasound is recommended at 7 weeks for confirming the pregnancy, excluding an ectopic pregnancy, confirming the presence of cardiac activity and establishing the pregnancy`s age and due date.

The second ultrasound is performed between 20 and 22 weeks of pregnancy to check the presence of possible fetal abnormalities, as the fetus is big enough for a careful evaluation of fetal anatomy. That`s why it`s also named a morphological ultrasound. The multiple pregnancy is also evaluated accurately now, as well as the baby`s growth parameters, the placenta`s position and the baby`s sex.

Lots of centers perform an ultrasound between weeks 11 and 14 to measure the nuchal translucency and the presence of fetal nasal bone which helps in diagnosing the Down syndrome. A new ultrasound can be recommended during the 32nd week or even later for determining the position of the fetus, his weight, the rhythm of growth, as well as the position and weight of the placenta. Some doctors perform a last ultrasound during the 39th – 40th weeks of pregnancy to check the quantity of amniotic liquid, weight and cardiac rhythm of the fetus. The total number of ultrasounds depends on the pregnancy health; if at an ultrasound were detected certain abnormalities, than the pregnancy requires an additional evaluation.

Which Is the Pregnancy`s Minimum Age when an Ultrasound Can Be Done?

In case of pregnancy, ultrasound is the only method that can visualize the fetus without adverse effects and without limiting the number of examinations.

The intrauterine evolution knows 2 stages:

  • Embryonic stage – up to 10 weeks of pregnancy
  • Fetal stage – from 10 weeks of pregnancy.

Ultrasounds can be performed:

  • In the embryonic stage – when their main purpose is to confirm the pregnancy, their position (intrauterine or ectopic), viability (demonstrated through the presence of tonus and heart beats, usually around 5 weeks of gestation through the endovaginal examination).
  • In the fetal stage – when the ultrasound is performed transabdominal and the main purpose is to detect abnormalities.

Does Ultrasound Have Side Effects?

There were numerous studies made that tried to demonstrate the effect of ultrasounds on embryo or fetus while developing. Studies from the last 35 years have shown the fact that an ultrasound doesn`t have adverse effects on the development of the fetus or that there would be a harmful cumulative effect after multiple exposures to ultrasound.

There are some smaller studies which suggested that ultrasound can increase the risk of health problems for the fetus: low birth weight, issues of communication and hearing or clumsiness. However, there isn`t enough evidence to prove it.

Do Ultrasounds Detect Certain Fetal Abnormalities?

A routine ultrasound shouldn`t scare a pregnant woman because in most cases this doesn`t identify major abnormalities offering guarantee for a healthy baby. Still, in some situations it can be detected some congenital anomalies, malformations or functional abnormalities more or less serious.

Not any fetal abnormality is synonym with a compromised pregnancy, lots of the health problems of the fetus being able to be treated even from the gestational period.

Some cardiac anomalies can be partially corrected through endoscopic surgeries. Cardiac arrhythmias (rhythm disorders) can be successfully treated by administrating some antiarrhythmic drugs. Some congenital abnormalities of the urinary tract can be corrected surgically.

An ultrasound is very important because if it detects certain fetal health problems that can be corrected prenatal, it can offer the necessary monitoring of the fetus until birth when the newborn will be able to receive the specialized medical treatment.

Ultrasounds offer the possibility of interrupting a compromised pregnancy (severe congenital malformations with a bad prognosis after birth) which protects the pregnant woman from a major psychological trauma.

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