MXR Imaging acquired Conquest Imaging in December 2018

Ultrasound Accuracy for Pregnancy

by J.Guerra on 2.26.2020

Expectant first-time mothers have all sorts of questions running through their heads. As the baby develops, the mother wonders about its health, if she will be a good mother, what the future will hold for the family, and if they will be one and done or have a big family. Medical professionals and doctors can only answer so much. They are smart people, but they don’t know everything. They aren’t able to predict the future or know what’s in the minds of others. What they can do is monitor the health and development of the baby and make educated predictions about the future. It’s kind of like predicting the future, but they use skill, science, and data to make those predictions. One of the best tools at their disposal is the ultrasound machine.

Prenatal care is the treatment most often associated with ultrasound machines. Ultrasound images of babies in utero are used in marketing campaigns, in movies and television, and are quite pervasive in the public consciousness. Long before the average person becomes a parent, they have some semblance of what an ultrasound image is and how it’s obtained. The ultrasound machine is a versatile machine that has many uses, while new uses are developing all the time.

The main technology of the ultrasound is not new; it’s based on sonar, sending and receiving and interpreting sound waves. While the basics are rudimentary, the ancillary technology in ultrasounds is cutting edge. Advances in 4D imaging and AI make ultrasounds among the most advanced medical equipment in the world. How reliable is ultrasound accuracy for pregnancy? Let’s find out.

HOW ACCURATE ARE THEY FOR PREDICTING DUE DATE?

This is a top-of-mind question for all expecting parents. They can gauge it on their own with a slight degree of accuracy, but a doctor can get a lot closer. Evidence suggests that the ultrasound is more accurate than using the last menstrual period for predicting when the baby is due. The ultrasound is more accurate during the first trimester, and early in the second trimester, it is accurate to within a week. Later in the second and into the third trimesters, the ultrasound will be less accurate in predicting. Keep in mind that this is only an estimate. No doctor can predict the exact day that a baby will be born, unless scheduling a cesarean section.

DETECTING FETAL HEARTBEAT

In detecting a fetal heartbeat, an ultrasound should be 100 percent accurate. If there is one, the ultrasound will detect it with ease. The heartbeat is viewable during the gestational period beyond seven to eight weeks. In the early part of the first trimester, it is difficult to differentiate between an earlier-than-estimated pregnancy and an overlooked miscarriage. It usually takes two ultrasounds with several days in between to confirm or rule out a miscarriage at this point. An abdominal ultrasound will be able to detect the heartbeat after eight weeks. If the pregnancy has a gestational age of less than eight weeks, then a transvaginal ultrasound is needed for an accurate reading.

DIAGNOSING A MISCARRIAGE

As mentioned above, in the first trimester it can be hard to differentiate between a pregnancy and a miscarriage based on the results of one ultrasound exam. Doctors will order a second one if they aren’t sure about what they are seeing. There are times when one ultrasound is able to determine pregnancy, so there is not a defined number of ultrasounds that will detect a miscarriage. It all depends on the skill of the technician, the doctor, and the machine doing the ultrasound. Tests like checking the woman’s hCG level are used in conjunction with an ultrasound to get an accurate diagnosis.

DIAGNOSING BIRTH DEFECTS

Doctors can use ultrasounds for diagnosing birth defects, but there are questions about the accuracy. It is believed that a second-trimester ultrasound performed between 16–20 weeks can detect three of four major birth defects. But it is not uncommon for a woman to have an ultrasound give a false positive for birth defects. It’s important for pregnant women to have this information before the exam is done so they can make informed decisions based on the results. Second-trimester ultrasounds have a higher success rate at finding anomalies in the fetus than in the first trimester. First-trimester exams can still provide important information. A study published in 2016 found that first-trimester ultrasounds were capable of finding anomalies. The researchers were successful in finding birth defects in 30 percent of women at low risk and 60 percent of women at high risk of having babies with anomalies. In other cases, like Down syndrome, ultrasounds can’t give a definite diagnosis, only show markers that indicate an elevated risk of certain conditions.

DETERMINING THE BABY’S GENDER

Midway through the pregnancy, an ultrasound can find out the gender of the baby, if you choose to know. For many mothers this is the one and only ultrasound they will have if everything is progressing normally. Ultrasound imaging is good enough to find the telltale signs of gender in the womb. The only limiting factors are the position of the baby and the skill of the ultrasound technician. If the baby isn’t cooperating and is in the wrong position, getting a clear image will be difficult. There are specific structures specific to males and females, beyond fully formed reproductive organs, that the technician will look for to determine the sex.

PREDICTING THE BABY’S SIZE

This is an area in which the ultrasound isn’t very reliable. Ultrasounds can be off by multiple pounds in predicting the weight and overall size of a baby. The best an ultrasound exam can do is estimate weight. The difficulty goes both ways, low and high. It is accepted that the exam is not good for predicting low birth weight, and estimates vary on assessing babies that are oversize. If the doctor is worried about low birth weight, there are other tools available that will give a better diagnosis.

MXR Imaging has portable Philips ultrasound machines for sale. Keep your staff adaptable and mobile with this versatile machine. Contact us today for availability.