Ultrasonographic Parameters for Fetal Weight Prediction

New Ultrasonographic Parameters for Fetal Weight Prediction

The hypothesis is to increase the predictability of the ultrasound examination evaluating new fetal parameters: in fact the thickness of the soft tissues can contribute significantly to the fetal weight and the characteristics of the thoracic cage may correlate with the fetal weight.

Study Overview

• Status: Completed
• Conditions: Fetal Growth Abnormality
• Intervention / Treatment: Diagnostic test: Obstetric Ultrasonography

Detailed Description

Estimation of fetal weight (EFW: Estimated Fetal Weight) with ultrasound examination is a common practice in obstetrics and is important for planning the mode and timing of birth, especially in pregnancies at risk for altered fetal growth.

The conditions most commonly associated with impaired fetal growth are:

• IUGR: in these cases the ultrasound estimate of fetal weight is fundamental to decide the timing of delivery, since the neonatal outcome correlates positively with the fetal weight as well as with the flowmetry parameters
• fetal macrosomia (fetal weight greater than 4500 g) associated or not with gestational diabetes: in such cases an accurate estimation of the fetal weight is necessary and careful evaluation of any fetal-pelvic disproportion to decide both the timing of the birth that can be anticipated compared to at the physiological end of pregnancy is the mode of birth, vaginal or laparotomic in the event of a pelvic fetus disproportion.

In the 1970s the estimate of fetal weight was based on the measurement of the symphysis-fundus uterine distance (SFH) for which:

• SFH <33 cm: predictive of a fetal weight <3100 gr
• SFH> 34 cm: predictive of a fetal weight = o> 4000 gr.

At present, the fetal weight estimate is performed with biometric ultrasound parameters:

• DBP: biparietal diameter
• HC: head circumference
• AC: abdominal circumference
• FL: femur length There are standardized tables of variation of these parameters according to the gestational epoch for which the knowledge of the correct gestational epoch is fundamental for the correct interpretation of the data.

The fetal weight is calculated using mathematical formulas automatically obtained from ultrasound equipment of which the most used:

• Shepard's formula as a function of BPD and AC.
• formula of Campbell and Wilkin: it is in function of the abdominal circumference
• Hadlock formula: use the combination of different biometric parameters (BPD-HC-AC-FL).

Even if the guidelines provide for three ultrasound examinations for physiological pregnancies (one for each trimester of pregnancy), it is common practice to evaluate the biometric ultrasound parameters at the end of pregnancy and in any case when the patient is admitted for the delivery. It is obvious that in this time of pregnancy a closer correlation between biometric parameters and fetal weight is observed.

The problems related to the ultrasound estimation of fetal weight are represented by:

• significant intra-operator variability
• reduced accuracy for extremes of fetal weight (small or macrosomic fetuses)
• about 10% discrepancy between estimated fetal weight on an echographic basis according to Hadlock and actual weight of the newborn at birth.

• Study Type: Observational
• Enrollment (Actual): 300

Contacts and Locations

Study Locations

• Italy
  • Napoli, Italy, 80138
    • Department of Woman, Child and General and Specialized Surgery, University of Campania "Luigi Vanvitelli"

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 14 years to 41 years (Adult)
• Accepts Healthy Volunteers: N/A
• Genders Eligible for Study: Female

• Sampling Method: Non-Probability Sample

Study Population

single pregnancies, free of complications, with delivery completed between 37 and 42 weeks, but within a week of the last ultrasound examination performed. Patients are selected among those candidates with elective caesarean section, pregnant who come to hospital for prodroma of labor and conditions that require induction of childbirth such as prolonged pregnancy or PROM.

Description

Inclusion Criteria:

• pregnant women

Exclusion Criteria:

• fetal structural and / or chromosomal anomalies
• multiple pregnancies
• premature births (gestational age <37w)

Study Plan

How is the study designed?

Design Details

• Observational Models: Cohort
• Time Perspectives: Prospective

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
biparietal diameter	Evaluation of biparietal diameter	9 months
head circumference	evaluation of head circumference	9 months
abdominal circumference	Evaluation of abdominal circumference	9 months
femur length	Evaluation of femur length	9 months
transtentorial diameter	Evaluation of transtentorial diameter	9 months
distance between L1-L4 lumbar vertebrae	Evaluation of distance between L1-L4	9 months
Fetal Weight	Evaluation of Fetal Weight	9 months

Collaborators and Investigators

• Sponsor: University of Campania "Luigi Vanvitelli"

Study record dates

Study Major Dates

• Study Start (Actual): January 1, 2019
• Primary Completion (Actual): April 18, 2019
• Study Completion (Actual): April 18, 2019

Study Registration Dates

• First Submitted: May 21, 2019
• First Submitted That Met QC Criteria: May 22, 2019
• First Posted (Actual): May 23, 2019

Study Record Updates

• Last Update Posted (Actual): May 24, 2019
• Last Update Submitted That Met QC Criteria: May 22, 2019
• Last Verified: May 1, 2019

More Information

Terms related to this study

• Keywords: fetal growth; ultrasonographic parameters
• Additional Relevant MeSH Terms: Body Weight; Fetal Weight
• Other Study ID Numbers: N.603

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: No

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No