Timing of Serial Ultrasounds (SUN)

The University of Texas System (UT)

Status: Unknown

Conditions: Interval Growth Ultrasound

Treatments: Device: Ultrasound

Study type: Interventional

Funder types: Other

Identifiers

NCT02719886

HSC-MS-15-0968

Details and patient eligibility

About

The purpose of this randomized controlled trial is to compare the frequency of the diagnosis of fetal growth abnormalities when ultrasound assessment is performed at 2 versus 4 week intervals.

Full description

While there is an agreement that women at risk for abnormalities of fetal growth should have serial ultrasound examinations in the 3rd trimester, there is a lack of consensus on how frequently these exams should be done. The American College of Obstetrics and Gynecology recommend that an ultrasound to assess fetal growth be performed between 2 to 4 weeks; however, there have been no prospective or randomized trials to determine whether the optimal interval should be closer to 2 weeks or delayed to 4 weeks. Currently, only 60% of fetuses' with abnormal growth are detected antenatally. There is equipoise of whether ultrasound every 2 versus 4 weeks improves the detection and subsequent newborn outcomes or merely leads to an increase in false positives and unnecessary interventions. It has been proposed, that if delivery occurs within 2 weeks of the ultrasound, the antenatal detection of abnormal growth may be more accurate and hence more likely to improve outcomes. Conversely, a shorter interval may result in confusion as to whether there is actual change in growth or merely variation in the measurement technique itself. Moreover, with the cost of ultrasound averaging approximately $200 per examination, the interval between ultrasounds can have major implications on public-health costs as well as the interventions that subsequently follow if an abnormality is detected.

The purpose of this randomized controlled trial is to compare the frequency of the diagnosis of fetal growth abnormalities when ultrasound assessment is performed at 2 versus 4 week intervals.

Enrollment: 228 estimated patients

Sex: Female

Ages: 18 to 50 years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

• Maternal age ≥ 18 years
• Singletons
• Gestational age ≥ 20 weeks to 27 weeks 6 days
• Has insurance, whether private or government issued
• High-risk pregnancy requiring serial fetal growth assessment as determined by the treating physician.
• Dating of pregnancy by ultrasound ≤ 21 weeks and 6 days of gestation or known date of conception in the setting of in vitro fertilization
• No known major anomalies

Exclusion criteria

• Known major fetal anomaly
• Multiple gestation (twins or triplets)

Trial design

228 participants in 2 patient groups

Fetal growth ultrasound every 2 weeks

Experimental group

Description:

Ultrasound to measure fetal growth every 2 weeks (i.e. 28, 30, 32, 34, 36, 38 weeks gestation).

Treatment:

Device: Ultrasound

Fetal growth ultrasound every 4 weeks

Active Comparator group

Description:

Ultrasound to measure fetal growth every 4 weeks (i.e. 28, 32 and 36 weeks gestation). Usual Care.

Treatment:

Device: Ultrasound