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NCT Number: NCT07333729

Effects of Spinal Anesthesia on the Fetal Autonomic Nervous System

Elective cesarean deliveries account for over 10% of births in France and are often scheduled around 39 weeks of gestation. When feasible, spinal anesthesia is considered the gold standard in such a clinical situation. However, a well-known complication is maternal hypotension, which may lead to placental hypoperfusion and fetal acidosis. Heart rate variability (HRV) markers reflect autonomic nervous system (ANS) activity, which plays a key role in maintaining fetal homeostasis.

The Lille University Hospital has developed a technology to assess parasympathetic activity through HRV analysis. This technology has been adapted to obtain an HRV markers specific of the fetal autonomic nervous system assessment: the Fetal Stress Index (FSI). Preclinical studies have shown that FSI correlates with parasympathetic fluctuations and fetal acidosis.

This pilot study aims to evaluate the impact of spinal anesthesia on fetal ANS activity during elective cesarean delivery using a continuous beat-to-beat fetal heart rate recording device: the TOCONAUTE device. FSI will be retrospectively computed to assess fetal autonomic response. Maternal ANS activity will also be monitored using the Analgesia Nociception Index (ANI). A secondary objective is to explore the predictive value of ANI and FSI for maternal hypotension or fetal hypoxia.

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Key information

Conditions

Obstetrics: Elective Caesarean Delivery Cardiovascular Diseases Hypotension Vascular Diseases

Age range

18 year–45 year

Sex eligibility

Female

Study type

Interventional

Phase

Not applicable

Primary location

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Pregnant woman scheduled for elective cesarean delivery
  • Age: over 18 and under 45 years
  • Gestational age ≥ 37 weeks of amenorrhea
  • Singleton pregnancy
  • Proficient in the French language
  • Participant has provided written informed consent to take part in the study
  • Affiliated with a national health insurance scheme

Exclusion criteria

  • Requirement for general anesthesia or combined epidural-spinal analgesia
  • Fetal malformation
  • Intrauterine fetal demise
  • Maternal and/or fetal cardiac rhythm disorders
  • History of heart transplantation
  • Open wound in an area covered or enclosed by one of the study devices
  • Risk of viral or infectious contamination of any component of the device
  • Hospitalization for medical termination of pregnancy
  • Sensory disorders resulting in lack of pain perception on the skin
  • Ongoing treatment that may alter autonomic nervous system activity (e.g., beta-blockers, anticholinergics, atropine)
  • Participant with an implanted medical device (e.g., pacemaker)
  • Known allergy to any component of the devices: polyamide, polyester, elastane, silver, or other synthetic materials
  • Participant whose anatomical area intended for ClearSight sensor placement is insufficient to allow proper application
  • Concurrent participation in another interventional research study

Treatment and study plan

Recording of fetal and maternal heart rate

Device

This study will be conducted in the maternity ward of the Jeanne de Flandre Maternity, Lille University Hospital, specifically in the operating room for cesarean delivery. The TOCONAUTE device will be placed on the mother's abdomen to record fetal heart rate. Recordings will be analyzed retrospectively using the ANI RELECTURE software to calculate the Fetal Stress Index (FSI). Participants will also be connected to the Analgesia Nociception Index (ANI) monitor and the ClearSight system to collect maternal cardiac output, heart-rate variability (HRV) indices, and continuous blood-pressure data. For each participant, the TOCONAUTE will remain in place on the abdomen for 12 minutes after intrathecal injection. These procedures will not interfere with the standard clinical care provided to the pregnant woman.

Primary outcomes

  1. To assess the impact of spinal anesthesia on fetal autonomic nervous system activity during elective cesarean delivery.

    Time frame: At 12 minutes after intrathecal injection

    Rate of Fetal Stress Index (FSI) compared with the pre-anesthesia baseline, computed from continuous fetal heart-rate recordings acquired with the TOCONAUTE device.

Secondary outcomes

  1. To assess the impact of spinal anesthesia on fetal autonomic nervous system activity at intermediate time points during elective cesarean delivery.

    Time frame: At placement, at injection, 1 min, 3 min, 6 min and 9 min during elective cesarean delivery.

    Rate of Fetal Stress Index (FSI) at multiple intermediate time points after intrathecal injection (at placement, at injection (T0) and at T+1, T+3, T+6, and T+9 minutes) compared with the pre-anesthesia baseline, computed from continuous fetal heart-rate recordings acquired with the TOCONAUTE device.

  2. To evaluate the evolution of maternal blood pressure following spinal anesthesia placement, up to 12 minutes after injection.

    Time frame: At intrathecal injection (T0) and at T+1, T+3, T+6, T+9, and T+12 minutes,

    Change from baseline in ClearSight® (Edwards Lifesciences®) monitoring parameters (systolic arterial pressure (SAP), mean arterial pressure (MAP) measured at intrathecal injection (T0) and at T+1, T+3, T+6, T+9, and T+12 minutes, relative to the pre-spinal anesthesia baseline.

  3. To evaluate the evolution of cardiac output following spinal anesthesia

    Time frame: At intrathecal injection (T0) and at T+1, T+3, T+6, T+9, and T+12 minutes

    Change from baseline in ClearSight® (Edwards Lifesciences®) monitoring parameter: cardiac index (CI) measured relative to the pre-spinal anesthesia baseline.

  4. To evaluate the evolution of cardiac output following spinal anesthesia

    Time frame: At intrathecal injection (T0) and at T+1, T+3, T+6, T+9, and T+12 minutes

    Change from baseline in ClearSight® (Edwards Lifesciences®) monitoring parameter: Hypotension Prediction Index (HPI) measured relative to the pre-spinal anesthesia baseline.

  5. Change in ANI measurements measured at placement, at intrathecal injection (T0) and at T+1, T+3, T+6, T+9, and T+12 minutes, relative to the pre-spinal anesthesia baseline, measured by ANI monitor medical device.

    Time frame: At placement, at intrathecal injection (T0) and at T+1, T+3, T+6, T+9, and T+12 minutes

    Change in ANI measurements measured relative to the pre-spinal anesthesia baseline.

  6. To compare fetal and maternal heart rate variability markers measured during the 12 minutes following spinal anesthesia placement, according to the maternal hypotension status.

    Time frame: At placement, at intrathecal injection (T0) and at T+1, +3, +6, +9, and +12 minutes

    Rate of FSI (Fetal Stress Index) and HPI (Hypotension Prediction Index) measured at placement, at intrathecal injection (T0) and at T+1, +3, +6, +9, and +12 minutes.

  7. To compare fetal and maternal cardiac output values measured during the 12 minutes following spinal anesthesia placement, according to the maternal hypotension status.

    Time frame: At placement, at intrathecal injection (T0) and at T+1, +3, +6, +9, and +12 minutes

    Rate of FSI and ANI measured at placement, at intrathecal injection (T0) and at T+1, +3, +6, +9, and +12 minutes.

  8. To compare fetal and maternal heart rate variability markers measured during the 12 minutes following spinal anesthesia placement, according to the neonatal acidosis status.

    Time frame: At placement, at intrathecal injection (T0) and at T+1, +3, +6, +9, and +12 minutes

    Rate of FSI and HPI measured at placement, at intrathecal injection (T0) and at T+1, +3, +6, +9, and +12 minutes, with analyses stratified by the presence or absence of neonatal acidosis (defined as umbilical arterial pH < 7.20 at birth).

  9. To compare fetal and maternal cardiac output values measured during the 12 minutes following spinal anesthesia placement, according to the neonatal acidosis status.

    Time frame: At placement, at intrathecal injection (T0) and at T+1, +3, +6, +9, and +12 minutes

    Rate of FSI and ANI measured at placement, at intrathecal injection (T0) and at T+1, +3, +6, +9, and +12 minutes, with analyses stratified by the presence or absence of neonatal acidosis (defined as umbilical arterial pH < 7.20 at birth).

Study contacts

Contact information is provided by the study sponsor or research team.

Charles Garabédian, PH

CONTACT

[email protected]

03 20 44 59 62

Mathilde Herbet

CONTACT

[email protected]

03.62.94.38.19

Sponsors and collaborators

Lead sponsor

University Hospital, Lille

Other

Collaborators

  • Clinical Investigation Centre for Innovative Technology Network

Registry information

Official study title

Evaluation of the Impact of Spinal Anesthesia on the Fetal Autonomic Nervous System During an Elective Caesarean Delivery

Acronym: RACHISNA

Important dates

Study start
2025
Primary completion
2025
Study completion
2026
First posted
Jan 12, 2026
Registry last updated
Jan 23, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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