Uterine Activity in Moderate-Severe Neonatal Encephalopathy: A Case Control Study

Neonatal Encephalopathy Clinical Trial

Official title:

Intrapartum Uterine Activity Monitoring and Partogram Characteristics: Can They Help Predict Foetuses With Poor Tolerance of Labour?

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT03122808
• Other study ID #: REC-2015-009
• Status: Completed
• Start date: September 1, 2016
• Est. completion date: October 18, 2021

Study information

• Verified date: May 2023
• Source: The Rotunda Hospital
• Contact: n/a
• Is FDA regulated: No
• Study type: Observational

Clinical Trial Summary

Excessive uterine activity may be one of several aetiological factors that contribute to depressed neurological function in the newborn. During labour, uterine contractions can compress the fetal cranium at pressures high enough to impair cerebral perfusion. Contraction rates greater than 7 in 15 minutes are associated with an increased risk of neonatal encephalopathy.

The American Congress of Obstetricians and Gynecologists defines uterine tachysystole as more than 5 contractions in 10 minutes, averaged over a 30-minute window. By this definition, excessive uterine activity is common and, at best, a non-specific predictor of depressed neurological function in the newborn. There is a need for predictors of neonatal encephalopathy that are more specific and clinically applicable.

Contraction and relaxation duration are two measures that closely reflect the proposed role of excessive uterine activity in the pathogenesis of neonatal encephalopathy. Prolonged contractions with short relaxation periods result in progressive reductions in fetal cerebral oxygenation. Shorter uterine contraction periods are associated with an increased risk of low umbilical cord potential of hydrogen (pH) values.

Our primary aim is to measure parameters of uterine activity, for example relaxation and contraction duration, and determine their relationship with the risk of neonatal encephalopathy. We will also investigate how measures of uterine activity interact with other measures of labour and fetal well-being, including cervical dilation rates and fetal heart rate patterns. In babies with neonatal encephalopathy, we will investigate the relationship of uterine activity with electrophysiological, radiological and developmental outcomes.

We will perform a retrospective case-control study of babies born in the Rotunda hospital from 2005 until the present. The assessor of the Cardiotocograph (CTG) recordings will be blind to the disease status of the infants. For each recording, every uterine contraction and rest interval will be measured. Summary variables created from these measures will be used to compare the case and control groups. The primary variable will be mean rest interval duration.

Description:

The advent of therapeutic hypothermia has improved outcomes for babies born with hypoxic-ischemic encephalopathy. However, the risk of death, seizures, cerebral palsy or intellectual impairment remains significant, especially among the most severely affected infants. Prevention remains a promising strategy to reduce the incidence of complications arising from hypoxic-ischaemic neonatal encephalopathy.

Excessive uterine activity may be one of several aetiological factors that contribute to depressed neurological function in the newborn. During labour, uterine contractions can compress the fetal cranium at pressures high enough to impair cerebral perfusion. Contraction rates greater than 7 in 15 minutes are associated with an increased risk of neonatal encephalopathy.

The American Congress of Obstetricians and Gynecologists defines uterine tachysystole as more than 5 contractions in 10 minutes, averaged over a 30-minute window. By this definition, excessive uterine activity is common and, at best, a non-specific predictor of depressed neurological function in the newborn. There is a need for predictors of neonatal encephalopathy that are more specific and clinically applicable.

Contraction and relaxation duration are two measures that closely reflect the proposed role of excessive uterine activity in the pathogenesis of neonatal encephalopathy. Prolonged contractions with short relaxation periods result in progressive reductions in fetal cerebral oxygenation. Shorter uterine contraction periods are associated with an increased risk of low umbilical cord pH values.

Our primary aim is to measure parameters of uterine activity, for example relaxation and contraction duration, and determine their relationship with the risk of neonatal encephalopathy. We will also investigate how measures of uterine activity interact with other measures of labour and fetal well-being, including cervical dilation rates and fetal heart rate patterns. In babies with neonatal encephalopathy, we will investigate the relationship of uterine activity with electrophysiological, radiological and developmental outcomes.

We will perform a retrospective case-control study of babies born in the Rotunda hospital from 2005 until the present. Cases and controls must be over 35 weeks gestational age and have at least 15 minutes of Cardiotocograph (CTG) recording from labour available for analysis. Cases will be babies with moderate or severe neonatal encephalopathy of apparent hypoxic-ischemic aetiology. Controls will be the first healthy babies born before and after the cases to satisfy the study criteria. Controls will be matched for parity.

The assessor of the CTG recordings will be blind to the disease status of the infants. For each recording, every uterine contraction and rest interval will be measured. Summary variables created from these measures will be used to compare the case and control groups. The primary variable will be mean rest interval duration.

For further detail please see the study protocol.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 264
• Est. completion date: October 18, 2021
• Est. primary completion date: January 1, 2021
• Accepts healthy volunteers: No
• Gender: All
• Age group: N/A and older

Eligibility

Cases

The inclusion criteria will be:

• Moderate or severe neonatal encephalopathy

• Gestational age of 35+0 weeks or greater

• Singleton pregnancy

• Inborn

The exclusion criteria will be:

• Non-hypoxic-ischaemic aetiology or postnatal hypoxic-ischaemia

• Major congenital abnormalities

• Less than 15 minutes of digital CTG recording from labour available Controls

The inclusion criteria will be:

• Gestational age of 35+0 weeks or greater

• Singleton pregnancy

• Inborn

The exclusion criteria will be:

• APGAR score of less than 5 at 1 minute or less than 7 at 5 or 10 minutes

• Admission to the neonatal unit

• Major congenital abnormalities

• Less than 15 minutes of digital CTG recording from labour available

Related Conditions & MeSH terms

• Brain Diseases
• Neonatal Encephalopathy

Intervention

Diagnostic Test:
• Uterine Activity Analysis
Analysis of components of uterine activity; contraction rate, length of contraction, length of relaxation and other values based off these measurements.
• Partogram Analysis
Analysis of slope of partogram

Locations

Country	Name	City	State
Ireland	The Rotunda Hospital	Dublin	Co. Dublin

Sponsors (1)

Lead Sponsor	Collaborator
The Rotunda Hospital

Country where clinical trial is conducted

Ireland, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Other	Contraction rate	Expressed as mean, maximum, 90th centile. Individual uterine activity measures will be analysed both as continuous and categorised variables and in terms of minutes elapsed above a certain threshold that is to be determined.	Whole CTG recording from start of labour to delivery
Other	Contraction duration	Expressed as mean, maximum, 90th centile. Individual uterine activity measures will be analysed both as continuous and categorised variables and in terms of minutes elapsed above a certain threshold that is to be determined.	Whole CTG recording from start of labour to delivery
Other	Excessive Uterine Activity Score	Composite score based on combined assessment of contraction rate, contraction duration and relaxation time.	Whole CTG recording from start of labour to delivery
Primary	Rest interval duration	Expressed as mean, maximum, 90th centile. Individual uterine activity measures will be analysed both as continuous and categorised variables and in terms of minutes elapsed above a certain threshold that is to be determined.	Whole CTG recording from start of labour to delivery
Secondary	Rest interval as a percentage of contraction-rest interval cycle	Expressed as mean, maximum, 90th centile. Individual uterine activity measures will be analysed both as continuous and categorised variables and in terms of minutes elapsed above a certain threshold that is to be determined.	Whole CTG recording from start of labour to delivery