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

The University of Texas Health Science Center, Houston113 enrolled

Overview

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).

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

DIAGNOSTIC

Masking

NONE

Enrollment

113

Conditions

Fetal Growth Abnormality Amniotic Fluid; Disorder

Interventions

Point-of-care ultrasound (POC-US)DIAGNOSTIC_TEST

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.

Routine antenatal careDIAGNOSTIC_TEST

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)

Formal ultrasoundDIAGNOSTIC_TEST

Formal growth ultrasound performed between 36-38.6 weeks by RDMS.

Eligibility

Sex: FEMALEMin age: 18 YearsMax age: 50 Years

Medical Language ↔ Plain English

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

Locations (1)

University of Texas Health Science Center of Houston

Houston, Texas, United States

Outcomes

Primary Outcomes

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.

Time frame: 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

Time frame: From 36 weeks Gestational age (GA) to 38.6 weeks GA

Secondary Outcomes

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.

Time frame: 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

Time frame: 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.

Time frame: From 28 weeks Gestational age (GA) to 38.6 weeks GA

Specificity of diagnostic methods for identification of birthweight < 10th percentile or > 90th percentile

Data from ClinicalTrials.gov

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Time frame: 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.

Time frame: 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

Time frame: 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.

Time frame: 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

Time frame: 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.

Time frame: 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

Time frame: 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.

Time frame: 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

Time frame: 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.

Time frame: 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

Time frame: 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.

Time frame: 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

Time frame: From 28 weeks Gestational age (GA) to time of delivery

Number of referrals for formal USE.

Time frame: 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.

Time frame: 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

Time frame: 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.

Time frame: from time of randomization until discharge (total time is about 15 weeks)