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

Not Applicable

Terminated

Conditions: Fetal Growth Abnormality
Amniotic Fluid; Disorder

Interventions: Diagnostic Test: Point-of-care ultrasound (POC-US)
Diagnostic Test: Routine antenatal care
Diagnostic Test: Formal ultrasound

Registration Number: NCT03857659

Lead Sponsor: The University of Texas Health Science Center, Houston

Brief Summary: 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).

Detailed Description: Not available

Recruitment & Eligibility

Status: TERMINATED

Sex: Female

Target Recruitment: 113

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

Study & Design

Study Type: INTERVENTIONAL

Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Point of care ultrasound (POC-US)	Point-of-care ultrasound (POC-US)	Point of care ultrasound (POC-US) to measure abdominal circumference and amniotic fluid every 4 weeks from 28-36 weeks
Routine antenatal care	Routine antenatal care	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)
Routine antenatal care	Formal ultrasound	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)
Point of care ultrasound (POC-US)	Formal ultrasound	Point of care ultrasound (POC-US) to measure abdominal circumference and amniotic fluid every 4 weeks from 28-36 weeks

Primary Outcome Measures

Name	Time	Method
Number of participants with abnormal fetal growth or amniotic fluid	From 36 weeks Gestational age (GA) to 38.6 weeks GA	Abnormal fetal growth or amniotic fluid as assessed by formal ultrasound by RDMS

Secondary Outcome Measures

Name	Time	Method
Specificity of diagnostic methods for identification of abnormal fetal growth or amniotic fluid	From 28 weeks Gestational age (GA) to 38.6 weeks GA	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.
Positive predictive value of diagnostic methods for identification of abnormal fetal growth or amniotic fluid	From 28 weeks Gestational age (GA) to 38.6 weeks GA	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.
Negative predictive value of diagnostic methods for identification of abnormal fetal growth or amniotic fluid	From 28 weeks Gestational age (GA) to 38.6 weeks GA	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.
Sensitivity of diagnostic methods for identification of abnormal fetal growth or amniotic fluid	From 28 weeks Gestational age (GA) to 38.6 weeks GA	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.
Sensitivity of diagnostic methods for identification of birthweight < 10th percentile or > 90th percentile	From 28 weeks Gestational age (GA) to time of delivery	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
Specificity of diagnostic methods for identification of birthweight < 10th percentile or > 90th percentile	From 28 weeks Gestational age (GA) to time of delivery	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
Positive predictive value of diagnostic methods for identification of birthweight < 10th percentile or > 90th percentile	From 28 weeks Gestational age (GA) to time of delivery	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
False positive rate of diagnostic methods for identification of birthweight < 10th percentile or > 90th percentile	From 28 weeks Gestational age (GA) to time of delivery	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
False negative rate of diagnostic methods for identification of birthweight < 10th percentile or > 90th percentile	From 28 weeks Gestational age (GA) to time of delivery	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
Number of referrals for formal USE.	From 28 weeks Gestational age (GA) to 36 weeks GA
Negative predictive value of diagnostic methods for identification of birthweight < 10th percentile or > 90th percentile	From 28 weeks Gestational age (GA) to time of delivery	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
False positive rate of diagnostic methods for identification of abnormal fetal growth or amniotic fluid	From 28 weeks Gestational age (GA) to 38.6 weeks GA	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.
Positive likelihood ratio of diagnostic methods for identification of abnormal fetal growth or amniotic fluid	From 28 weeks Gestational age (GA) to 38.6 weeks GA	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.
False negative rate of diagnostic methods for identification of abnormal fetal growth or amniotic fluid	From 28 weeks Gestational age (GA) to 38.6 weeks GA	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.
Positive likelihood ratio of diagnostic methods for identification of birthweight < 10th percentile or > 90th percentile	From 28 weeks Gestational age (GA) to time of delivery	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
Negative likelihood ratio of diagnostic methods for identification of abnormal fetal growth or amniotic fluid	From 28 weeks Gestational age (GA) to 38.6 weeks GA	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.
Negative likelihood ratio of diagnostic methods for identification of birthweight < 10th percentile or > 90th percentile	From 28 weeks Gestational age (GA) to time of delivery	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
Total costs of care from the health system perspective	from time of randomization until discharge (total time is about 15 weeks)	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.
Number of participants with composite neonatal morbidity	at delivery	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.
Number of participants with composite maternal morbidity	labor until delivery (total time is about 1-48 hrs)	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