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Timing of Serial Ultrasounds

Not Applicable
Conditions
Interval Growth Ultrasound
Interventions
Device: Ultrasound
Registration Number
NCT02719886
Lead Sponsor
The University of Texas Health Science Center, Houston
Brief Summary

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.

Detailed 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.

Recruitment & Eligibility

Status
UNKNOWN
Sex
Female
Target Recruitment
228
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)

Study & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Arm && Interventions
GroupInterventionDescription
Fetal growth ultrasound every 2 weeksUltrasoundUltrasound to measure fetal growth every 2 weeks (i.e. 28, 30, 32, 34, 36, 38 weeks gestation).
Fetal growth ultrasound every 4 weeksUltrasoundUltrasound to measure fetal growth every 4 weeks (i.e. 28, 32 and 36 weeks gestation). Usual Care.
Primary Outcome Measures
NameTimeMethod
Frequency of detection of fetal growth abnormalities, starting at 28 weeks gestational ageup to 72 hours after delivery
Secondary Outcome Measures
NameTimeMethod
Frequency of detection of amniotic fluid abnormality, starting at 28 weeks gestational ageUp to 72 hours after delivery
Composite neonatal morbidity (CNM)up to 72 hours from neonatal discharge from hospital
Composite maternal morbidity (CMM)up to 72 hours from mother's discharge from hospital
Birthweight compared to antenatal estimated fetal weightsAt delivery

Comparison of estimated fetal weight by ultrasound to actual birth weight at delivery

Cost of interventions resulting from detection of abnormal growth or amniotic fluidup to 72 hours from neonatal discharge from hospital

e.g. additional ultrasounds, antenatal testing, hospital admission, induction, antepartum or intrapartum complications

Trial Locations

Locations (1)

Memorial Hermann Hospital, Texas Medical Center

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Houston, Texas, United States

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