Serial Third Trimester Abdominal Circumference and Amniotic Fluid Measurements Versus Routine Care

Study Overview
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Brief Summary
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The purpose of this study us to compare the rate of prenatal identification of abnormal fetal growth or amniotic fluid between clinical evaluation of uterine size by symphysis fundal height (SFH) measurements versus point-of-care ultrasound (POC-US) evaluation of abdominal circumference (AC) and maximum vertical pocket (MVP).

Official Title
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Serial Third Trimester Abdominal Circumference and Amniotic Fluid Measurements Versus Routine Care: A Randomized Controlled Trial (STAR Trial)

Conditions
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Fetal Growth Abnormality, Amniotic Fluid; Disorder

Intervention / Treatment
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* Diagnostic Test: Point-of-care ultrasound (POC-US)
* Diagnostic Test: Routine antenatal care
* Diagnostic Test: Formal ultrasound


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Maternal age of 18 at the time of consent Singleton gestation Ultrasound examination that confirms or revises the estimated date of delivery (EDD) before 22 0/7 weeks of gestational age Gestational age ≥ 24 weeks gestation Exclusion Criteria: Abnormal aneuploidy screening (1st trimester screening, 2nd trimester screening, integrated screening, NIPT) Fetal chromosomal or genetic abnormalities Fetal malformations or soft markers identified on fetal anatomy survey Current pregnancy is a result of in vitro fertilization Documented uterine bleeding after 24 weeks gestation. Unobserved self-reported bleeding with confirmed intact pregnancy on ultrasound after the bleeding episode is not an exclusion criterion. Uterine/placental abnormalities including uterine malformations (i.e bicornuate uterus, didelphus uterus), abnormal placentation (placenta previa, accrete, percreta), uterine fibroids. Cerclage in the current pregnancy History of intrauterine fetal demise Fetal isoimmunization or alloimmunization History of medical complications such as: Cancer (including melanoma but excluding other skin cancers) Endocrine disease including thyroid disease (recently diagnosed or whose medication dose is not stable), adrenal disease, diabetes mellitus (pregestational and gestational). Renal disease with altered renal function (creatinine > 0.9 or proteinuria) Epilepsy or other seizure disorder Any collagen disease (lupus erythematosus, scleroderma, etc.) Active liver disease (acute hepatitis, chronic active hepatitis, persistently abnormal liver enzymes) Hematological disorder including alloimmune and isoimmune thrombocytopenia but excluding mild iron deficiency anemia (Hb > 9 gm/dl). Patients with sickle cell disease are excluded. Chronic pulmonary disease including asthma requiring regular use of medication and active tuberculosis (TB). An asthma inhaler used on an as needed basis (PRN) for a cold or an asthma attack is not considered regular use. Heart disease except mitral value prolapse not requiring medication Cardiovascular disorders: chronic hypertension Liver disorders accounting for cholestasis Infectious diseases: HIV, Cytomegalovirus (CMV), toxoplasmosis, parvovirus B19

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 50 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Diagnostic
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Point of care ultrasound (POC-US)<br>Point of care ultrasound (POC-US) to measure abdominal circumference and amniotic fluid every 4 weeks from 28-36 weeks | Diagnostic Test: Point-of-care ultrasound (POC-US)<br>* POC-US evaluation will be conducted using the portable ultrasound machine, which is capable of straight-line measurements for assessment of the amniotic fluid, as well as ellipse measurements for determination of abdominal circumference. POC-US evaluation will be conducted every 4 weeks from 28-36 weeks.<br>Diagnostic Test: Formal ultrasound<br>* Formal growth ultrasound performed between 36-38.6 weeks by RDMS.<br>|
| Active Comparator: Routine antenatal care<br>Routine care with fundal height measurement at each antenatal appointment every 2 weeks from 28-36 weeks. As well as clinically indicated obstetric ultrasound by a Registered Diagnostic Medical Sonographer (RDMS) | Diagnostic Test: Routine antenatal care<br>* Routine care with fundal height measurement at each antenatal appointment every 2 weeks from 28-36 weeks. As well as clinically indicated obstetric ultrasound by a Registered Diagnostic Medical Sonographer (RDMS)<br>Diagnostic Test: Formal ultrasound<br>* Formal growth ultrasound performed between 36-38.6 weeks by RDMS.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of participants with abnormal fetal growth or amniotic fluid | Abnormal fetal growth or amniotic fluid as assessed by clinical evaluation of uterine size by SFH versus POC-US evaluation. | From 28 weeks Gestational age (GA) to 36 weeks GA | 
| Number of participants with abnormal fetal growth or amniotic fluid | Abnormal fetal growth or amniotic fluid as assessed by formal ultrasound by RDMS | From 36 weeks Gestational age (GA) to 38.6 weeks GA | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Sensitivity of diagnostic methods for identification of abnormal fetal growth or amniotic fluid | Test performance characteristics of SFH measurements and POC US for identification of abnormal fetal growth or amniotic fluid using formal USE as the diagnostic standard. | From 28 weeks Gestational age (GA) to 38.6 weeks GA | 
| Sensitivity of diagnostic methods for identification of birthweight < 10th percentile or > 90th percentile | Test performance characteristics of SFH measurements and POC US for identification of birthweight < 10th percentile or > 90th percentile using the neonates' gestational age at delivery as the standard | From 28 weeks Gestational age (GA) to time of delivery | 
| Specificity of diagnostic methods for identification of abnormal fetal growth or amniotic fluid | Test performance characteristics of SFH measurements and POC US for identification of abnormal fetal growth or amniotic fluid using formal USE as the diagnostic standard. | From 28 weeks Gestational age (GA) to 38.6 weeks GA | 
| Specificity of diagnostic methods for identification of birthweight < 10th percentile or > 90th percentile | Test performance characteristics of SFH measurements and POC US for identification of birthweight < 10th percentile or > 90th percentile using the neonates' gestational age at delivery as the standard | From 28 weeks Gestational age (GA) to time of delivery | 
| Positive predictive value of diagnostic methods for identification of abnormal fetal growth or amniotic fluid | Test performance characteristics of SFH measurements and POC US for identification of abnormal fetal growth or amniotic fluid using formal USE as the diagnostic standard. | From 28 weeks Gestational age (GA) to 38.6 weeks GA | 
| Positive predictive value of diagnostic methods for identification of birthweight < 10th percentile or > 90th percentile | Test performance characteristics of SFH measurements and POC US for identification of birthweight < 10th percentile or > 90th percentile using the neonates' gestational age at delivery as the standard | From 28 weeks Gestational age (GA) to time of delivery | 
| Negative predictive value of diagnostic methods for identification of abnormal fetal growth or amniotic fluid | Test performance characteristics of SFH measurements and POC US for identification of abnormal fetal growth or amniotic fluid using formal USE as the diagnostic standard. | From 28 weeks Gestational age (GA) to 38.6 weeks GA | 
| Negative predictive value of diagnostic methods for identification of birthweight < 10th percentile or > 90th percentile | Test performance characteristics of SFH measurements and POC US for identification of birthweight < 10th percentile or > 90th percentile using the neonates' gestational age at delivery as the standard | From 28 weeks Gestational age (GA) to time of delivery | 
| False positive rate of diagnostic methods for identification of abnormal fetal growth or amniotic fluid | Test performance characteristics of SFH measurements and POC US for identification of abnormal fetal growth or amniotic fluid using formal USE as the diagnostic standard. | From 28 weeks Gestational age (GA) to 38.6 weeks GA | 
| False positive rate of diagnostic methods for identification of birthweight < 10th percentile or > 90th percentile | Test performance characteristics of SFH measurements and POC US for identification of birthweight < 10th percentile or > 90th percentile using the neonates' gestational age at delivery as the standard | From 28 weeks Gestational age (GA) to time of delivery | 
| False negative rate of diagnostic methods for identification of abnormal fetal growth or amniotic fluid | Test performance characteristics of SFH measurements and POC US for identification of abnormal fetal growth or amniotic fluid using formal USE as the diagnostic standard. | From 28 weeks Gestational age (GA) to 38.6 weeks GA | 
| False negative rate of diagnostic methods for identification of birthweight < 10th percentile or > 90th percentile | Test performance characteristics of SFH measurements and POC US for identification of birthweight < 10th percentile or > 90th percentile using the neonates' gestational age at delivery as the standard | From 28 weeks Gestational age (GA) to time of delivery | 
| Positive likelihood ratio of diagnostic methods for identification of abnormal fetal growth or amniotic fluid | Test performance characteristics of SFH measurements and POC US for identification of abnormal fetal growth or amniotic fluid using formal USE as the diagnostic standard. | From 28 weeks Gestational age (GA) to 38.6 weeks GA | 
| Positive likelihood ratio of diagnostic methods for identification of birthweight < 10th percentile or > 90th percentile | Test performance characteristics of SFH measurements and POC US for identification of birthweight < 10th percentile or > 90th percentile using the neonates' gestational age at delivery as the standard | From 28 weeks Gestational age (GA) to time of delivery | 
| Negative likelihood ratio of diagnostic methods for identification of abnormal fetal growth or amniotic fluid | Test performance characteristics of SFH measurements and POC US for identification of abnormal fetal growth or amniotic fluid using formal USE as the diagnostic standard. | From 28 weeks Gestational age (GA) to 38.6 weeks GA | 
| Negative likelihood ratio of diagnostic methods for identification of birthweight < 10th percentile or > 90th percentile | Test performance characteristics of SFH measurements and POC US for identification of birthweight < 10th percentile or > 90th percentile using the neonates' gestational age at delivery as the standard | From 28 weeks Gestational age (GA) to time of delivery | 
| Number of referrals for formal USE. |  | From 28 weeks Gestational age (GA) to 36 weeks GA | 
| Number of participants with composite neonatal morbidity | Composite neonatal morbidity is defined as any of the following: 1) Apgar score < 3 at 5 min, 2) birth trauma, 3) hypotension requiring vasopressor support, 4) hypoxic-ischemic encephalopathy, 5) infection, 6) intracranial or subgaleal hemorrhage, 7) meconium aspiration syndrome, 8) perinatal death, 9) respiratory support, or 10) seizure. 4. The rate of composite neonatal morbidity, including any of the following: 1) Apgar score < 3 at 5 min, 2) birth trauma, 3) hypotension requiring vasopressor support, 4) hypoxic-ischemic encephalopathy, 5) infection, 6) intracranial or subgaleal hemorrhage, 7) meconium aspiration syndrome, 8) perinatal death, 9) respiratory support, or 10) seizure. | at delivery | 
| Number of participants with composite maternal morbidity | Composite maternal morbidity is defined as any of the following: o 1) chorioamnionitis, 2) cesarean delivery in labor, 3) wound infection, 4) transfusion, 5) deep venous thrombus or pulmonary embolism, 6) admission to intensive care unit, 7) postpartum hemorrhage, or 8) death | labor until delivery (total time is about 1-48 hrs) | 
| Total costs of care from the health system perspective | 6. The total costs of care from the health system perspective during the study period (from the date of enrollment through the mothers' post-delivery discharge and the infants' post-birth discharge). The hospital costs (for ER visits, admissions, delivery, and neonatal care) will be obtained from the Memorial Hermann Hospital cost-accounting system. The costs of physician services received during the study period by the mothers and the newborns will be estimated using relative value units (RVUs) based on claims data. The intervention arm will be augmented by the cost of the POC-US examinations. The POC-US costs will include the costs of the POC provider time (estimated based on limited time-motion studies, salary, and fringe data) and the depreciation costs of the portable ultrasound equipment. | from time of randomization until discharge (total time is about 15 weeks) | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Pregnancy, Ultrasound, neonatal morbidity