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

Study Overview
=================
Brief 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.

Detailed 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.

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

Conditions
-----------------
Neonatal Encephalopathy

Intervention / Treatment
-----------------
* Diagnostic Test: Uterine Activity Analysis
* Diagnostic Test: Partogram Analysis


Participation Criteria
=================
Eligibility Criteria
-----------------
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
Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Neonatal encephalopathy<br>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 | Diagnostic Test: Uterine Activity Analysis<br>* Analysis of components of uterine activity; contraction rate, length of contraction, length of relaxation and other values based off these measurements.<br>Diagnostic Test: Partogram Analysis<br>* Analysis of slope of partogram<br>|
| Control<br>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 | Diagnostic Test: Uterine Activity Analysis<br>* Analysis of components of uterine activity; contraction rate, length of contraction, length of relaxation and other values based off these measurements.<br>Diagnostic Test: Partogram Analysis<br>* Analysis of slope of partogram<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| 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 Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| 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 | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
Tachysystole, Excessive Uterine Activity