1. Aetna considers ultrasounds not medically necessary if done solely to determine the fetal sex, or to provide parents with a view and photograph of the fetus.

2. A fetal ultrasound with detailed anatomic examination is considered medically necessary to evaluate the fetus for amniotic band syndrome (also known as amniotic constriction band syndrome), or if there are known or suspected fetal anatomic abnormalities, including anatomic abnormalities due to genetic conditions (see attached ICD-9 coding).  More than one detailed ultrasound fetal anatomic examination per pregnancy per practice is considered experimental and investigational, as there is inadequate evidence of the clinical utility of multiple serial detailed fetal anatomic ultrasound examinations during pregnancy.

3. Detailed ultrasound fetal anatomic examination is considered experimental and investigational for all other indications  including routine evaluation of pregnant women who smoke or abuse cannabis.  There is inadequate evidence of the clinical utility of detailed ultrasound fetal anatomic examination for indications other than evaluation of suspected fetal anatomic abnormalities.  Detailed ultrasound fetal anatomic examination is not considered medically necessary for routine screening of normal pregnancy.

4. Aetna considers three-dimensional (3D) and four-dimensional (4D) fetal ultrasounds experimental and investigational because of a lack of evidence that 3D and 4D ultrasounds alter management over standard two-dimensional (2D) ultrasounds such that clinical outcomes are improved.

For Aetna’s policy on first trimester ultrasonographic assessment of fetal nuchal skinfold thickness, see CPB 282 - Noninvasive First Trimester Down Syndrome Screening.

See also: CPB 106 - Fetal Echocardiograms.

This policy is based in part on The American College of Obstetricians and Gynecologists (ACOG) Practice Bulletin on Ultrasonography in Pregnancy  and guidelines from the Society for Maternal-Fetal Medicine (SMFM).

Ultrasonography in pregnancy should be performed only when there is a valid medical indication.  ACOG (2008) stated, "The use of either two-dimensional or three-dimensional ultrasonography only to view the fetus, obtain a picture of the fetus, or determine the fetal sex without a medical indication is inappropriate and contrary to responsible medical practice." 

Indications for a first-trimester ultrasound (performed before 13 weeks and 6 days of gestation) include:

• To confirm the presence of an intrauterine pregnancy
• To evaluate a suspected ectopic pregnancy
• To evaluate vaginal bleeding
• To evaluate pelvic pain
• To estimate gestational age
• To diagnosis or evaluate multiple gestations
• To confirm cardiac activity
• As adjunct to chorionic villus sampling, embryo transfer, or localization and removal of an intrauterine device
• To assess for certain fetal anomalies, such as anencephaly, in patients at high risk
• To evaluate maternal pelvic or adnexal masses or uterine abnormalities
• To screen for fetal aneuploidy

• To evaluate suspected hydatidiform mole.

ACOG recommended that in the absence of specific indications, the optimal time for an obstetric ultrasound examination is between 18 - 20 weeks of gestation because anatomically complex organs, such as the fetal heart and brain, can be imaged with sufficient clarity to allow detection of many major malformations.  This recommendation is based primarily on consensus and expert opinion (Level C).  ACOG stated that it may be possible to document normal structures before 18 weeks of gestation but some structures can be difficult to visualize at that time because of fetal size, position, and movement; maternal abdominal scars; and increased maternal abdominal wall thickness.  A second or third trimester ultrasound examination, however, may pose technical limitations for an anatomic evaluation due to suboptimal imaging, and when this occurs, ACOG recommended documentation of the technical limitation and that a follow-up examination may be helpful. 

ACOG uses the terms "standard" (also called basic), "limited," and "specialized" (also called detailed) to describe various types of ultrasound examinations performed during the second or third trimesters.  

Standard Examination

A standard ultrasound includes an evaluation of fetal presentation, amniotic fluid volume, cardiac activity, placental position, fetal biometry, and fetal number, plus an anatomic survey.  A standard examination of fetal anatomy includes the following essential elements:

• Head, face and neck (cerebellum, choroid plexus, cisterna magna, lateral cerebral ventricles, midline falx, cavum septi pellucidi, upper lip)
• Chest (heart)
• Abdomen (stomach, kidneys, bladder, umbilical cord insertion site into the fetal abdomen, umbilical cord vessel number)
• Spine (cervical, thoracic, lumbar, and sacral spine)
• Extremities (presence or absence of legs and arms)
• Sex (medically indicated in low-risk pregnancies only for the evaluation of multiple gestations).

Limited Examination

A limited examination does not replace a standard examination and is performed when a specific question requires investigation (e.g., to confirm fetal heart activity in a patient experiencing vaginal bleeding or to establish fetal presentation during labor).  A limited examination may be performed during the first trimester to evaluate interval growth, estimate amniotic fluid volume, evaluate the cervix, and assess the presence of cardiac activity. 

Specialized Examination

A detailed or targeted anatomic examination is performed when an anomaly is suspected on the basis of history, laboratory abnormalities, or the results of either the limited or standard examination.  Other specialized examinations might include fetal Doppler ultrasonography, biophysical profile, amniotic fluid assessment, fetal echocardiography, or additional biometric measurements.  Specialized examinations are performed by an operator with experience and expertise in such ultrasonography who determines that components of the examination on a case-by-case basis.

Indications for a second and third trimester ultrasound include the following:

• Estimation of gestational age
• Evaluation of fetal growth
• Evaluation of vaginal bleeding
• Evaluation of cervical insufficiency
• Evaluation of abdominal and pelvic pain
• Determination of fetal presentation
• Evaluation of suspected multiple gestation
• Adjunct to amniocentesis or other procedure
• Significant discrepancy between uterine size and clinical dates
• Evaluation of pelvic mass
• Examination of suspected hydatidiform mole
• Adjunct to cervical cerclage placement
• Evaluation of suspected ectopic pregnancy
• Evaluation of suspected fetal death
• Evaluation of suspected uterine abnormality
• Evaluation for fetal well-being
• Evaluation for premature rupture of membranes of premature labor
• Evaluation for abnormal biochemical markers
• Follow-up evaluation of a fetal anomaly
• Follow-up evaluation of placental location for suspected placenta previa
• Evaluation in those with a history of previous congenital anomaly
• Evaluation of fetal condition in late registrants for prenatal care
• To assess for findings that may increase the risk of aneuploidy

• To screen for fetal anomalies.

The Society for Maternal-Fetal Medicine (SMFM) has stated that a fetal ultrasound with detailed anatomic examination (CPT 76811) is not necessary as a routine scan for all pregnancies (SMFM, 2004).  Rather, this scan is necessary for a known or suspected fetal anatomic or genetic abnormality (i.e., previous anomalous fetus, abnormal scan during pregnancy, etc.).  Thus, the SMFM has stated that the performance of this scan is expected to be rare outside of referral practices with special expertise in the identification of, and counseling about, fetal abnormalities (SMFM, 2004).

SMFM has also determined that no more than one fetal ultrasound with detailed anatomic examination is necessary per pregnancy, per practice, when medically necessary (SMFM, 2004).  Once this detailed fetal anatomical exam is done, a second one should not be performed unless there are extenuating circumstances with a new diagnosis.  The SMFM has stated that it is appropriate to repeat the detailed fetal anatomical ultrasound examination when a patient is seen by another maternal-fetal medicine specialist practice, for example, for a second opinion on a fetal anomaly, or if the patient is referred to a tertiary center in anticipation of delivering an anomalous fetus at a hospital with specialized neonatal capabilities.

A focused ultrasound assessment is sufficient for follow-up to provide a reexamination of a specific organ or system known or suspected to be abnormal, or when doing a focused assessment of fetal size by measuring the bi-parietal diameter, abdominal circumference, femur length, or other appropriate measurements (SMFM, 2004).

An ultrasound without detailed anatomic examination is appropriate for a fetal maternal evaluation of the number of fetuses, amniotic/chorionic sacs, survey of intracranial, spinal and abdominal anatomy, evaluation of a 4-chamber heart view, assessment of the umbilical cord insertion site, assessment of amniotic fluid volume, and evaluation of maternal adenexa when visible and appropriate (SMFM, 2004).

Amniotic band sequence refers to a highly variable spectrum of congenital anomalies that occur in association with amniotic bands. Amniotic banding affects approximately 1 in 1200 live births. It is also believed to be the cause of 178 in 10,000 miscarriages. Up to 50% of cases have other congenital anomalies including cleft lip, cleft palate, and clubfoot deformity. Hand and finger anomalies occur in up to 80%. The diagnosis is based upon the presence of characteristic structural findings on prenatal ultrasound or postnatal physical examination. The diagnosis should be suspected when limb amputations or atypical body wall or craniofacial defects are present, or when bands of amnion are seen crossing the gestational sac and adherent to the fetus.

Three-Dimensional and Four-Dimensional Ultrasound in Obstetrics

Three-dimensional (3D) ultrasound can furnish a 3-dimensional image of the fetus. To create a 3-dimensional image, a transducer takes a series of thin slices of the subject, and a computer translates these images and presents them in three dimensions.

Proponents of 3D ultrasound scanning have argued that volumetric measurements from 3D ultrasound scan are more accurate and that both clinicians and parents can better appreciate a certain abnormality with a 3D scan than a standard 2-dimensional (2D) scan. In addition, there is the possibility of increasing psychological bonding between the parents and the baby (Ji, et al., 2005).

In the diagnosis of congenital anomalies, there is evidence to suggest that smaller defects such as spina bifida, cleft lip and palate, and polydactyly may be more lucidly demonstrated with 3D ultrasound (Gonçalves, et al., 2005; Kurjak, et al., 2007). Other more subtle features such as low-set ears, facial dysmorphia or clubbling of feet may be better assessed, which has the potential to lead to more effective diagnoses of chromosomal abnormalities.

In addition, the use of 3D technology can reduce scanning time while maintaining adequate visualization of the fetus in obstetrical ultrasound (Benacerraf, et al., 2005; Benacerraf, et al., 2006).

More recently, 4-dimensional (4D) or dynamic 3D scanners have come on the market, with the attraction of being able to look at fetal movements. These have also been referred to as "reassurance scans" or "entertainment scans." Proponents argue that 4D scans may have an important catalytic effect for mothers to bond to their babies before birth. However, the impact of 4D scans on diagnosis and management of fetal abnormalities is unknown.

Three-dimensional ultrasound appears to have been useful in research on fetal embryology. However, there is no evidence that the results of 3D ultrasound alters clinical management over standard 2D ultrasound such that clinical outcomes are improved. Whether 3D ultrasound will provide unique, clinically relevant information remains to be seen.

Current guidelines on ultrasonography in pregnancy from the American College of Obstetricians and Gynecologists (2008) state: "The technical advantages of 3-dimensional ultrasonography include its ability to acquire and manipulate an infinite number of planes and to display ultrasound planes traditionally inaccessible by 2-dimensional ultrasonography.  Despite these technical advantages, proof of a clinical advantage of 3-dimensional ultrasonography in prenatal diagnosis in general is still lacking.  Potential areas of promise include fetal facial anomalies, neural tube defects, and skeletal malformations where 3-dimensional ultrasonography may be helpful in diagnosis as an adjunct to, but not a replacement for, 2-dimensional ultrasonography.  Until clinical evidence shows a clear advantage to conventional 2-dimensional ultrasonography, 3-dimensional ultrasonography is not considered a required modality at this time."