Anesthesia for non-obstetric surgery during pregnancy in a tertiary referral center: a 16-year retrospective, matched case-control, cohort study

Anesthetic recommendations for maternal and fetal safety in nonobstetric surgery: a balancing act

PURPOSE OF REVIEW

Nonobstetric surgery during pregnancy is associated with maternal and fetal risks. Several physiologic changes create unique challenges for anesthesiologists. This review highlights physiologic changes of pregnancy and presents clinical recommendations based on recent literature to guide anesthetic management for the pregnant patient undergoing nonobstetric surgery.

RECENT FINDINGS

Nearly every anesthetic technique has been safely used in pregnant patients. Although it is difficult to eliminate confounding factors, exposure to anesthetics could endanger fetal brain development. Perioperative fetal monitoring decisions require an obstetric consult based on anticipated maternal and fetal concerns. Given the limitations of fasting guidelines, bedside gastric ultrasound is useful in assessing aspiration risk in pregnant patients. Although there is concern about appropriateness of sugammadex for neuromuscular blockade reversal due its binding to progesterone, preliminary literature supports its safety.

SUMMARY

These recommendations will equip anesthesiologists to provide safe care for the pregnant patient and fetus undergoing nonobstetric surgery.

Perioperative management of surgical procedure during pregnancy: a systematic review

Background

Approximately 1-2% of pregnant women undergo non-obstetric surgery under anaesthesia during their pregnancy. This review specifically targets anaesthesia management for pregnant women undergoing non-obstetric surgery in resource-limited settings.

Methods

Following the delineation of primary questions, scope, and inclusion criteria, a comprehensive search strategy utilizing advanced techniques was implemented across electronic sources, databases, and websites to identify relevant articles. A rigorous screening process was applied during the literature evaluation. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 statement guided the conduct of this review, ensuring adherence to standardized reporting practices.

Results

A total of 240 articles were initially identified from databases and websites. After screening titles and abstracts, 85 papers were excluded, and an additional 43 were removed due to duplication. Subsequently, 68 items were subjected to eligibility screening. Finally, 30 papers that specifically addressed anaesthetic considerations for pregnant women undergoing non-obstetric operations were reviewed.

Conclusion

Thorough preoperative evaluation is essential for all patients, with particular attention to modifications in anaesthetic management to accommodate physiological changes during pregnancy. Urgent and emergent surgeries should proceed promptly during pregnancy to optimize outcomes for both the mother and foetus. Maintaining uteroplacental perfusion generally involves avoiding maternal hypoxaemia, hypotension, hyper- and hypocapnia, temperature extremes, and stress. When deemed safe, regional anaesthesia may offer favourable outcomes for both the mother and foetus.

Non-obstetric surgery during pregnancy and the effects on maternal and fetal outcomes: A systematic review

BACKGROUND AND OBJECTIVE

Non-obstetric surgery is fairly common in pregnant women. We performed a systematic review to update data on non-obstetric surgery in pregnant women. The aim of this review was to evaluate the effects of non-obstetric surgery during pregnancy on pregnancy, fetal and maternal outcomes.

METHODS

A systematic literature search of MEDLINE and Scopus was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The search span was from January 2000 to November 2022. Thirty-six studies matched the inclusion criteria, and 24 publications were identified through reference mining; 60 studies were included in this review. Outcome measures were miscarriage, stillbirth, preterm birth, low birth weight, low Apgar score, and infant and maternal morbidity and mortality rates.

RESULTS

We obtained data for 80,205 women who underwent non-obstetric surgery and data for 16,655,486 women who did not undergo surgery during pregnancy. Prevalence of non-obstetric surgery was between 0.23% and 0.74% (median 0.37%). Appendectomy was the most common procedure with median prevalence of 0.10%. Near half (43%) of the procedures were performed during the second trimester, 32% during the first trimester, and 25% during the third trimester. Half of surgeries were scheduled, and half were emergent. Laparoscopic and open techniques were used equally for abdominal cavity. Women who underwent non-obstetric surgery during pregnancy had increased rate of stillbirth (odds ratio (OR) 2.0) and preterm birth (OR 2.1) compared to women without surgery. Surgery during pregnancy did not increase rate of miscarriage (OR 1.1), low 5 min Apgar scores (OR 1.1), the fetus being small for gestational age (OR 1.1) or congenital anomalies (OR 1.0).

CONCLUSIONS

The prevalence of non-obstetric surgery has decreased during last decades, but still two out of 1000 pregnant women have scheduled surgery during pregnancy. Surgery during pregnancy increases the risk of stillbirth, and preterm birth. For abdominal cavity surgery, both laparoscopic and open approaches are feasible.

Adverse Fetal Outcomes and Maternal Mortality Following Nonobstetric Abdominopelvic Surgery in Pregnancy: A Systematic Review and Meta-analysis

OBJECTIVE

To quantify the absolute risks of adverse fetal outcomes and maternal mortality following nonobstetric abdominopelvic surgery in pregnancy.

SUMMARY BACKGROUND DATA

Surgery is often necessary in pregnancy, but absolute measures of risk required to guide perioperative management are lacking.

METHODS

We systematically searched MEDLINE, EMBASE, and EvidenceBased Medicine Reviews from January 1, 2000, to December 9, 2020, for observational studies and randomized trials of pregnant patients undergoing nonobstetric abdominopelvic surgery. We determined the pooled proportions of fetal loss, preterm birth, and maternal mortality using a generalized linear random/mixed effects model with a logit link.

RESULTS

We identified 114 observational studies (52 [46%] appendectomy, 34 [30%] adnexal, 8 [7%] cholecystectomy, 20 [17%] mixed types) reporting on 67,111 pregnant patients. Overall pooled proportions of fetal loss, preterm birth, and maternal mortality were 2.8% (95% CI 2.2-3.6), 9.7% (95% CI 8.3-11.4), and 0.04% (95% CI 0.02-0.09; 4/10,000), respectively. Rates of fetal loss and preterm birth were higher for pelvic inflammatory conditions (eg, appendectomy, adnexal torsion) than for abdominal or nonurgent conditions (eg, cholecystectomy, adnexal mass). Surgery in the second and third trimesters was associated with lower rates of fetal loss (0.1%) and higher rates of preterm birth (13.5%) than surgery in the first and second trimesters (fetal loss 2.9%, preterm birth 5.6%).

CONCLUSIONS

Absolute risks of adverse fetal outcomes after nonobstetric abdom- inopelvic surgery vary with gestational age, indication, and acuity. Pooled estimates derived here identify high-risk clinical scenarios, and can inform implementation of mitigation strategies and improve preoperative counselling.

Patient-Centered Care in the Management of Cancer During Pregnancy

The management of cancer during pregnancy requires a patient-centered, multidisciplinary approach to balance maternal and fetal well-being given the rarity of this clinical scenario and lack of substantial data. Involvement of oncology and nononcology medical specialists and ethical, legal, and psychosocial supports, as needed, is instrumental in navigating the complexities of care for this patient population. Critical periods of fetal development and physiological changes in pregnancy must be considered when planning diagnostic and therapeutic approaches during pregnancy. The complexity of symptom recognition and interventional approaches contributes to diagnostic delays of cancers during pregnancy. Ultrasound and whole-body diffusion-weighted magnetic resonance imaging are safe throughout pregnancy. Surgery can be safely performed throughout pregnancy, with the early second trimester preferred for intra-abdominal surgery. Chemotherapy can be safely administered after 12-14 weeks of gestation until 1-3 weeks before the anticipated delivery. Most targeted and immunotherapeutic agents are contraindicated during pregnancy because of limited data. Pelvic radiation during pregnancy is absolutely contraindicated, while if radiation to the upper body is needed, administration should only be considered early in pregnancy. To ensure that the total cumulative fetal exposure to ionizing radiation does not exceed 100 mGy, early inclusion of the radiology team in the care plan is required. Closer prenatal monitoring is recommended for maternal and fetal treatment-related toxicities. Delivery before 37 weeks of gestation should be avoided if possible, and vaginal delivery is preferred unless obstetrically indicated or specific clinical scenarios. Postpartum, breastfeeding should be discussed, and the neonate should receive blood work to assess for acute toxicities with follow-up arranged for long-term monitoring.

Effects of cumulative duration of repeated anaesthesia exposure on foetal brain development in the ovine model

OBJECTIVE

Anaesthesia is required in 0.4-1% of pregnant women, and prolonged and repeated exposures to anaesthesia may be required. It is unknown whether these exposures may result in foetal neurotoxicity in humans. As sheep have a gestation comparable to that of humans, the objective of this study was to analyse the neurodevelopmental outcome of ovine foetuses that had been exposed in utero to repeated and prolonged anaesthesia.

DESIGN

Randomized controlled preclinical study.

SETTING

Anaesthesia for non-obstetric surgery during pregnancy.

ANIMALS

Twenty-four healthy pregnant Swifter ewes.

INTERVENTIONS

The ewes were randomized to no anaesthesia exposure (control-group), single exposure (at gestational age 68-70 days), or repeated exposure (at gestational age 68-70 days and 96-98 days) to 2.5 h of sevoflurane anaesthesia and maternal laparotomy. All lambs were delivered at approximately term gestation (gestational age: 140-143 days).

MEASUREMENTS

The primary outcome was neuron density in the frontal cortex 24 h after birth for the control-group versus the repeated-exposure-group. Key secondary outcome was the time needed to achieve the milestone of standing. Secondary outcomes included other neurobehavioural assessments (e.g., motoric milestones) and histological parameters quantified in multiple brain regions (neuron density, total cell density, proliferation, inflammation, synaptogenesis, astrocytes and myelination).

MAIN RESULTS

Neuron density in the frontal cortex did not differ between groups (mean ± standard deviation: control-group: 403 ± 39, single-exposure group: 436 ± 23 and repeated-exposure-group: 403 ± 40 neurons/mm2, control-group versus repeated-exposure-group: p = 0.986, control-group versus single-exposure-group: p = 0.097). No significant difference was observed for the time needed to achieve the milestone of standing. Only very limited differences were observed for other histological outcome parameters and neurobehavioural assessments.

CONCLUSIONS

There is no evidence for foetal neuronal injury or neurobehavioural impairments after a cumulative duration of 5 h repetitive prenatal anaesthesia in sheep.

Neurodevelopmental outcomes after prenatal exposure to anaesthesia for maternal surgery: a propensity-score weighted bidirectional cohort study

Up to 1% of pregnant women undergo anaesthesia for non-obstetric surgery. This study investigated neurodevelopmental outcomes after prenatal anaesthesia for maternal surgery. A bidirectional cohort study of children born between 2001 and 2018 was performed: neurodevelopmental outcomes of children who had received prenatal anaesthesia for maternal surgery were prospectively compared with unexposed children, with exposure status being assessed retrospectively. Children exposed to anaesthesia for obstetric and fetal surgery were excluded. The primary outcome was the global executive composite of the behaviour rating inventory of executive function score. Our secondary outcomes were: total problems; internalising problems and externalising problems derived from the child behaviour checklist; psychiatric diagnoses; and learning disorders. In 90% of exposed children, there was a single mean (SD) antenatal anaesthesia exposure lasting 91(94) min. There was a broad spectrum of indications, with abdominal surgery being most frequent. Parents of 129 exposed (response rate 68%) and 453 unexposed (response rate 63%) children participated. There were no arguments for non-response bias. After propensity weighting, there were no statistically significant differences in primary outcome, with a weighted mean difference (95%CI) of exposed minus unexposed children of 1.9 (-0.4-4.2), p = 0.10; or any of the secondary outcomes. Sensitivity analyses confirmed the robustness. Exploratory analyses, however, showed significant differences in certain subgroups for the primary outcome, (e.g. for intra-abdominal surgery, exposure duration > 1 h) and some cognitive subdomains (e.g. working memory and attention). This bidirectional cohort study, the largest investigation on the subject to date, has found no evidence in the general population for an association between prenatal exposure to anaesthesia and impaired neurodevelopmental outcomes.

Direct and indirect effects on child neurocognitive development when maternal cancer is diagnosed during pregnancy: What do we know so far?

Cancer during pregnancy threatens the lives of mother and foetus and its incidence is rising, making it an emerging medical challenge. Evidence on the direct impact of cancer therapies on neonatal outcomes resulted in general guidelines for maternal treatment that safeguards foetal development. Less focus has been placed on indirect factors, in pre- and postnatal periods, that may exert long-term impacts specifically on child neurocognition. Foetal development, in the context of maternal cancer during pregnancy, may be influenced directly by exposure to cancer diagnostics and (co-)treatment, or indirectly through maternal inflammation, malnutrition, hormonal fluctuations, prematurity, and psycho-biological stress. Maternal stress and insecure mother-infant bonding related to postpartum cancer treatment may further impact child cognitive-behavioural development. Understanding the independent and synergistic effects of the factors impacting neurocognitive development creates the opportunity to intervene during the oncological treatment to improve the child's long-term outcome, both by medical and psychosocial care and support.

Neurodevelopmental effects of maternal blood pressure management with noradrenaline during general anaesthesia for nonobstetric surgery in the pregnant rabbit model

BACKGROUND

In pregnant women, anaesthesia-induced hypotension is commonly treated using phenylephrine or noradrenaline, the rationale being to maintain uterine perfusion pressure and thereby uterine blood flow. Evidence for this strategy during general anaesthesia for nonobstetric surgery is absent.

OBJECTIVE

To analyse the effects of treating anaesthesia-induced hypotension with noradrenaline on brain development of rabbit foetuses of mothers subjected to general anaesthesia for nonobstetric surgery. We hypothesised that treatment of maternal hypotension would improve foetal outcomes.

DESIGN

Randomised controlled laboratory study using 21 pregnant rabbits (does) at 28 days of gestation.

INTERVENTION

Two hours of sevoflurane anaesthesia for a laparotomy without treatment of anaesthesia-induced hypotension (hypotension group) or with maintaining maternal mean arterial pressure above 80% of the awake value using noradrenaline (noradrenaline group). In the control group, does remained untouched. At term, all pups were delivered by caesarean section. One day later, the neurobehaviour of the pups was assessed and brains were harvested.

MAIN OUTCOMES

Neuron density in the frontal cortex for the comparison of noradrenaline groups versus hypotension groups was the primary outcome; the neurobehavioural scores and other histological outcomes were secondary outcomes.

RESULTS

In the noradrenaline groups and hypotension groups, neuron density in the frontal cortex was similar (1181 ± 162 versus 1189 ± 200 neurons mm-2, P = 0.870). However, significantly less foetal survival, lower sensory scores in neurobehavioural assessment and less proliferation were observed in the noradrenaline group when compared with the hypotension group. Neuron densities in other regions, total cell densities, biometrics and synaptogenesis were not affected. There were no differences between the control group and hypotension group.

CONCLUSION

During general anaesthesia for nonobstetric surgery in rabbits, treatment of anaesthesia-induced hypotension using noradrenaline did not affect neuron densities but was associated with impaired foetal outcomes according to several secondary outcome parameters. Further studies are needed to investigate any clinical relevance and to determine the target blood pressure in pregnant women during general anaesthesia.

Vulval cancer in pregnancy: Two case reports

Vulval cancer is rare in women of reproductive age. We report two cases of vulval squamous cell carcinoma (VSCC) in pregnancy. They presented with a solitary labial mass, at 20 and 21 weeks of gestation, diagnosed as stage 1B VSCC based on clinical examination and cross-sectional imaging. In the first case, the patient underwent close clinical surveillance whilst pregnant and had an elective caesarean section at 39 weeks of gestation. Two months post-partum she underwent a radical anterior vulvectomy and bilateral groin sentinel lymph node biopsy. In the second case, the patient underwent an anterior vulvectomy at 33 weeks of gestation followed by a vaginal delivery at 37 weeks of gestation. Six weeks post-natally she had bilateral groin sentinel lymph node biopsies. We conclude that surgical resection is safe during pregnancy under spinal anaesthesia but it can be deferred until the post-partum period if the cancer presents at early stage.

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Vulval cancer is rare in pregnancy and management is tailored according to gestation age.

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Surgical resection of a local tumour for symptom control is feasible antenatally and the decision should be made on a case-by-case basis with antenatal surveillance of the tumour.

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Staging surgery for inguinal lymphatics should be deferred until the post-natal period if there is no suspicion of clinical or radiology metastasis.

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Sentinel inguinal lymph node biopsy is absolutely contraindicated during the antenatal period due to risks of radiation exposure of the foetus.

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Vaginal birth is possible after vulvectomy and reconstructive surgery may be considered in the future.

Management of Nephrolithiasis in Pregnancy: Multi-Disciplinary Guidelines From an Academic Medical Center

Introduction: The management of nephrolithiasis during pregnancy can be stressful for urologists due to concerns for investigations and treatments that may pose risk of fetal harm, and unfamiliarity with optimal management of these complex patients. In response, we created multi-disciplinary evidence-based guidelines to standardize the care for obstetric patients presenting with flank pain and suspicion for nephrolithiasis. Methods: A multi-disciplinary team involving Urology, Obstetric Anesthesiology, Obstetrics and Gynecology, Diagnostic Radiology, and Interventional Radiology from a single academic medical center was assembled. A PubMed search was performed using keywords of pregnancy/antepartum, nephrolithiasis/calculi/kidney stones, ureteroscopy, non-obstetric surgery, complications, preterm delivery, MRI, computerized tomography, renal bladder ultrasound (RBUS), and anesthesia to identify relevant articles. Team members reviewed their respective areas to create a comprehensive set of guidelines. One invited external expert reviewed the guidelines for validation purposes. Results: A total of 54 articles were reviewed for evidence synthesis. Four guideline statements were constructed to guide diagnosis and imaging, and seven statements to guide intervention. Guidelines were then used to create a diagnostic and intervention flowchart for ease of use. In summary, RBUS should be the initial diagnostic study. If diagnostic uncertainty still exists, a non-contrast CT scan should be obtained. For obstetric patients presenting with a septic obstructing stone, urgent decompression should be achieved. We recommend ureteral stent placement as the preferred intervention if local factors allow. Conclusions: We present a standardized care pathway for the management of nephrolithiasis during pregnancy. Our aim is to standardize and simplify the clinical management of these complex scenarios for urologists.

Hematuria in pregnancy due to renal arteriovenous malformation: A case report

A 31-year-old pregnant woman at 22 weeks and 2 days of gestation presented to the emergency room with complaints of painless hematuria and passage of clots. Initial computed tomography angiography (CTA) of the abdomen and pelvis performed after ultrasound revealed evidence of blood products in the bladder. However, the CTA did not reveal any source of bleeding. Given hemodynamic instability and persistent pain, the patient was taken to the operating room for a cystoscopy, which revealed bleeding from the left renal unit, giving rise to suspicion of a renal arteriovenous malformation (AVM). The patient then underwent left renal digital subtraction angiography (DSA), which produced no evidence of active bleeding. Due to high clinical suspicion and ongoing symptomatic hematuria, she underwent DSA a second time, which did demonstrate renal AVM bleeding, and embolization was performed. This case highlights the importance of cystoscopy in diagnosing a renal AVM in a pregnant patient despite the risks of general anesthesia during pregnancy.

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Diagnosis of renal arteriovenous malformations during pregnancy can be difficult.

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A high index of suspicion is necessary to diagnose renal arteriovenous malformation.

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Diagnosis and management of a woman at 22 weeks of gestation are described.

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The patient subsequently had an uneventful pregnancy and delivered at term.

Anesthetic Management of a Patient With a Ruptured Heterotopic Pregnancy for Emergency Exploratory Laparotomy

Heterotopic pregnancy (HP) is an uncommon clinical condition characterized by the coexistence of intrauterine and extra-uterine pregnancies. HP is a diagnostic challenge as the typical methods for the early diagnosis of ectopic pregnancy are confounded by the simultaneous presence of intrauterine pregnancy (IUP). Ruptured HP is a potentially life-threatening obstetric emergency and can result in significant morbidity and mortality. Early diagnosis is the key to a favorable outcome. With the increasing number of patients undergoing artificial reproductive technology (ART), which is an important risk factor for HP, the odds of encountering HP patients are also growing. Anesthesiologists are challenged by the need to manage a bleeding obstetric patient while simultaneously ensuring the safety of the IUP. We present perioperative management of a patient with bleeding ruptured HP for emergency laparotomy who went on to have a successful twin delivery 37w3d via cesarean section.

Minimally Invasive Surgery in Pregnancy

If it is medically necessary to perform nonobstetrical abdominal surgery in pregnancy, a minimally invasive approach should be considered. The benefits of laparoscopy are well known and current studies promote the safety of laparoscopy in pregnancy, when certain guidelines are followed. This article will review the safety of surgery in pregnancy, maternal physiology, fetal considerations, maternal obesity, laparoscopic cerclage, large adnexal mass, and complications. Guidelines for surgery will be reviewed as well.

Anesthesia for Nonobstetric Surgery in Pregnancy

Nonobstetric surgery during pregnancy occurs in 1% to 2% of pregnant women. Physiologic changes during pregnancy may have an impact when anesthesia is needed. Anesthetic agents commonly used during pregnancy are not associated with teratogenic effects in clinical doses. Surgery-related risks of miscarriage and prematurity need to be elucidated with well-designed studies. Recommended practices include individualized use of intraoperative fetal monitoring and multidisciplinary planning to address the timing and type of surgery, anesthetic technique, pain management, and thromboprophylaxis. Emergency procedures should be performed immediately and elective surgery should be deferred during pregnancy.

Maternal sevoflurane exposure induces temporary defects in interkinetic nuclear migration of radial glial progenitors in the fetal cerebral cortex through the Notch signalling pathway

OBJECTIVES

The effects of general anaesthetics on fetal brain development remain elusive. Radial glial progenitors (RGPs) generate the majority of neurons in developing brains. Here, we evaluated the acute alterations in RGPs after maternal sevoflurane exposure.

METHODS

Pregnant mice were exposed to 2.5% sevoflurane for 6 hours on gestational day 14.5. Interkinetic nuclear migration (INM) of RGPs in the ventricular zone (VZ) of the fetal brain was evaluated by thymidine analogues labelling. Cell fate of RGP progeny was determined by immunostaining using various neural markers. The Morris water maze (MWM) was used to assess the neurocognitive behaviours of the offspring. RNA sequencing (RNA-Seq) was performed for the potential mechanism, and the potential mechanism validated by quantitative real-time PCR (qPCR), Western blot and rescue experiments. Furthermore, INM was examined in human embryonic stem cell (hESC)-derived 3D cerebral organoids.

RESULTS

Maternal sevoflurane exposure induced temporary abnormities in INM, and disturbed the cell cycle progression of RGPs in both rodents and cerebral organoids without cell fate alternation. RNA-Seq analysis, qPCR and Western blot showed that the Notch signalling pathway was a potential downstream target. Reactivation of Notch by Jag1 and NICD overexpression rescued the defects in INM. Young adult offspring showed no obvious cognitive impairments in MWM.

CONCLUSIONS

Maternal sevoflurane exposure during neurogenic period temporarily induced abnormal INM of RGPs by targeting the Notch signalling pathway without inducing long-term effects on RGP progeny cell fate or offspring cognitive behaviours. More importantly, the defects of INM in hESC-derived cerebral organoids provide a novel insight into the effects of general anaesthesia on human brain development.

Effects of general anaesthesia during pregnancy on neurocognitive development of the fetus: a systematic review and meta-analysis

BACKGROUND

The US Food and Drug Administration warned that exposure of pregnant women to general anaesthetics may impair fetal brain development. This review systematically evaluates the evidence underlying this warning.

METHODS

PubMed, EMBASE, and Web of Science were searched from inception until April 3, 2020. Preclinical and clinical studies were eligible. Exclusion criteria included case reports, in vitro models, chronic exposures, and exposure only during delivery. Meta-analyses were performed on standardised mean differences. The primary outcome was overall effect on learning/memory. Secondary outcomes included markers of neuronal injury (apoptosis, synapse formation, neurone density, and proliferation) and subgroup analyses.

RESULTS

There were 65 preclinical studies included, whereas no clinical studies could be identified. Anaesthesia during pregnancy impaired learning and memory (standardised mean difference -1.16, 95% confidence interval -1.46 to -0.85) and resulted in neuronal injury in all experimental models, irrespective of the anaesthetic drugs and timing in pregnancy. Risk of bias was high in most studies. Rodents were the most frequently used animal species, although their brain development differs significantly from that in humans. In a minority of studies, anaesthesia was combined with surgery. Monitoring and strict control of physiological homeostasis were below preclinical and clinical standards in many studies. The duration and frequency of exposure and anaesthetic doses were often much higher than in clinical routine.

CONCLUSION

Anaesthesia-induced neurotoxicity during pregnancy is a consistent finding in preclinical studies, but translation of these results to the clinical situation is limited by several factors. Clinical observational studies are needed.

PROSPERO REGISTRATION NUMBER

CRD42018115194.

The effect of xenon on fetal neurodevelopment following maternal sevoflurane anesthesia and laparotomy in rabbits

BACKGROUND

There is concern that maternal anesthesia during pregnancy impairs brain development of the human fetus. Xenon is neuroprotective in pre-clinical models of anesthesia-induced neurotoxicity in neonates. It is not known if xenon also protects the developing fetal brain when administered in addition to maternal sevoflurane-anesthesia during pregnancy.

OBJECTIVE

To investigate the effects of sevoflurane and xenon on neurobehaviour and neurodevelopment of the offspring in a pregnant rabbit model.

METHODS

Pregnant rabbits on post-conception day 28 (term = 31d) underwent two hours of general anesthesia with 1 minimum alveolar concentration (MAC) of sevoflurane in 30% oxygen (n = 17) or 1 MAC sevoflurane plus 50-60 % xenon in 30% oxygen (n = 10) during a standardized laparotomy while receiving physiological monitoring. A sham-group (n = 11) underwent monitoring alone for two hours. At term, the rabbits were delivered by caesarean section. On the first postnatal day, neonatal rabbits underwent neurobehavioral assessment using a validated test battery. Following euthanasia, the brains were harvested for neurohistological analysis. A mixed effects-model was used for statistical analysis.

RESULTS

Maternal cardiopulmonary parameters during anesthesia were within the reference range. Fetal survival rates were significantly higher in the sham-group as compared to the sevoflurane-group and the fetal brain/body weight ratio was significantly lower in the sevoflurane-group as compared with the sham- and xenon-group. Pups antenatally exposed to anesthesia had significantly lower motor and sensory neurobehavioral scores when compared to the sham-group (mean ± SD; sevo: 22.70 ± 3.50 vs. sevo+xenon: 22.74 ± 3.15 vs. sham: 24.37 ± 1.59; overall p = 0.003; sevo: 14.98 ± 3.00 vs. sevo+xenon: 14.80 ± 2.83 vs. sham: 16.43 ± 2.63; overall p = 0.006; respectively). Neuron density, neuronal proliferation and synaptic density were reduced in multiple brain regions of the exposed neonates. The co-administration of xenon had no measurable neuroprotective effects in this model.

CONCLUSIONS

In rabbits, sevoflurane anesthesia for a standardized laparotomy during pregnancy resulted in impaired neonatal neurobehavior and a decreased neuron count in several regions of the neonatal rabbit brain. Co-administration of xenon did not prevent this effect.

Effects of Maternal Abdominal Surgery on Fetal Brain Development in the Rabbit Model

INTRODUCTION

Anesthesia during pregnancy can impair fetal neurodevelopment, but effects of surgery remain unknown. The aim is to investigate effects of abdominal surgery on fetal brain development. Hypothesis is that surgery impairs outcome.

METHODS

Pregnant rabbits were randomized at 28 days of gestation to 2 h of general anesthesia (sevoflurane group, n = 6) or to anesthesia plus laparoscopic appendectomy (surgery group, n = 13). On postnatal day 1, neurobehavior of pups was assessed and brains harvested. Primary outcome was neuron density in the frontal cortex, and secondary outcomes included neurobehavioral assessment and other histological parameters.

RESULTS

Fetal survival was lower in the surgery group: 54 versus 100% litters alive at birth (p = 0.0442). In alive litters, pup survival until harvesting was 50 versus 69% (p = 0.0352). No differences were observed for primary outcome (p = 0.5114) for surviving pups. Neuron densities were significantly lower in the surgery group in the caudate nucleus (p = 0.0180), but not different in other regions. No differences were observed for secondary outcomes. Conclusions did not change after adjustment for mortality.

CONCLUSION

Abdominal surgery in pregnant rabbits at a gestational age corresponding to the end of human second trimester results in limited neurohistological changes but not in neurobehavioral impairments. High intrauterine mortality limits translation to clinical scenario, where fetal mortality is close to zero.

Effects of Pregnancy Anesthesia on Fetal Nervous System

The effects of general anesthesia on the developing brain remain a great concern in the medical field and even in the public, and most researches in this area focus on infancy and childhood. In recent years, with the continuous development of medical technology, the number of operations during pregnancy is increasing, however, studies on general anesthesia during pregnancy are relatively lacking. The mid-trimester of pregnancy is a critical period, and is regarded as a safe period for surgery, but it is a fragile period for the development of the central nervous system and is particularly sensitive to the impact of the environment. Our research group found that general anesthesia may have adverse effects on fetal neurodevelopment during the mid-trimester. Therefore, in this review, we summarize the characteristics of anesthesia during pregnancy, and the related research of the anesthesia’s impacts on the development of central nervous system were introduced.

Hippocampus is more vulnerable to neural damages induced by repeated sevoflurane exposure in the second trimester than other brain areas

During the rapidly developing and sensitive period of the central nervous system (CNS), a harmful stimulus may have serious consequences. The effect of anesthetic exposure on the development of the offspring's CNS during pregnancy is still unclear and has been widely concerned. In the present study, we compared the susceptibility of the hippocampus with those of other brain regions in offsprings when the mother mice were exposed to repeated sevoflurane. We found that other than affecting motor sensation, emotion, or social behavior of offspring mice, repeated sevoflurane exposure induced significant memory deficiency. Compared with other brain regions, the hippocampus, which is the key component of the brain serving for learning and memory, was more vulnerable to repeated sevoflurane exposure. We also found that repeated sevoflurane exposure to mother mice could inhibit the axon development of hippocampal neurons. We also predicted that N6-methyladenosine modification of mRNA might play an essential role in the vulnerability of the hippocampus to sevoflurane, while the underlying cellular mechanism needs to be explored in the future. Our study may provide a new perspective for studying the mechanism of hippocampus-specific injury induced by sevoflurane exposure.

Factors Affecting Maternal and Fetal Outcomes of Non-Obstetric Surgery and Anesthesia during Pregnancy: a Retrospective Review of Data at a Single Tertiary University Hospital

BACKGROUND

Anesthesia during pregnancy for non-obstetric surgery is generally known to have a negative impact on maternal and fetal outcomes. We assessed the risk of adverse outcomes in fetuses and mothers associated with non-obstetric surgery.

METHODS

This retrospective study analyzed clinical data on pregnant women who received non-obstetric surgeries at a tertiary university hospital. We reviewed maternity admissions using hospital administrative data during the last 16 years. The outcome assessment included the presence of preterm labor, premature birth, abortion, or stillbirth and the data of newborns. Statistical analyses were performed using the t-test, χ² test, and multiple logistic regression was used for risk analysis.

RESULTS

The incidence of non-obstetric surgery during pregnancy was 0.96%. Gestational age at or above 20 weeks increased the risk of all adverse events 4.5 fold when it was compared to gestational age less than 20 weeks, although the events were only preterm labor or premature birth and no fetal loss. All fetal loss cases occurred in patients at less than 20 weeks of pregnancy. The risk of adverse outcome increased by 2% for every 1 minute increase in anesthesia time. Babies of the mothers who had the adverse outcome event showed lower birth weight and higher neonatal intensive care unit admission rate than those of babies of the mothers without any adverse event after the surgery.

CONCLUSION

Physicians should acknowledge and prepare for common possible adverse events at the stage of pregnancy after non-obstetric surgery, and effort to shorten the duration of surgery and anesthesia is needed.

Pregnancy-preserving Laparoendoscopic Single-site Surgery for Gynecologic Disease: A Case Series

STUDY OBJECTIVE

The study objective was to assess the feasibility of laparoendoscopic single-site surgery (LESS) for the management of nonobstetric, gynecologic disease processes in pregnant patients.

DESIGN

A retrospective case series of 13 pregnant women aged 21 to 42 years who underwent LESS for various gynecologic pathology. If able to be contacted, the patients were followed up until the delivery of the fetus.

SETTING

The surgeries were performed in a single institution between January 2015 and June 2019.

PATIENTS

The patients were selected if a laparoscopic intervention was indicated.

INTERVENTIONS

The cases included 6 ovarian cystectomies and 2 salpingo-oophorectomies for adnexal masses; 1 myomectomy for a degenerated myoma; 1 salpingectomy for a heterotopic pregnancy; 2 cerclage placements for recurrent pregnancy loss and cervical insufficiency; and 1 paratubal cystectomy. The patients underwent LESS through a 2.5-cm umbilical incision. The masses were exteriorized using a laparoscopic specimen retrieval bag, with the exception of 2 large adnexal masses, which were aspirated at the incision site, exteriorized after content drainage, and cystectomies performed extracorporeally. The fascial incision was repaired with a permanent suture.

MEASUREMENTS AND MAIN RESULTS

Various data were collected from patients, including age, surgical and obstetric history, gestational age at surgery, and ultrasonic imaging results. The outcomes measured were operative duration, intraoperative bleeding, postoperative symptoms, fetal monitoring before and after surgery, pathologic findings, conversions, intraoperative complications, and pregnancy outcomes. Eight cases were performed in the first trimester, 4 in the second trimester, and 1 in the third trimester, with the surgeries lasting between 45 minutes and 298 minutes. The blood loss ranged from 5 mL to 300 mL, and postoperative symptoms of mild pelvic or abdominal pain were reported. There were 2 conversions to traditional multiport laparoscopic surgery for the 2 cerclage cases, and there were no open surgery conversions or intraoperative complications. The fetal heart rate ranged between 130 beats per minute and 167 beats per minute postoperatively. Of the 9 patients who were able to be contacted for follow-up, all had successful deliveries. One patient was healthy at 31 weeks and 5 days without complication at the time of her last follow-up.

CONCLUSION

LESS may be performed by experienced surgeons on gravid patients in any trimester for adnexal masses, myomas, heterotopic pregnancy, and cervical incompetence. Future multiple-center studies may provide further evidence that LESS is a feasible and safe option for gynecologic surgery during pregnancy.

Maternal surgery during pregnancy has a transient adverse effect on the developing fetal rabbit brain

BACKGROUND

Recently, the US Food and Drug Administration called for cautious use of anesthetic drugs during pregnancy. In 0.2-2% of pregnancies, nonobstetric surgery is being performed. The consequences of anesthesia during pregnancy on fetal development remain unclear, and preclinical studies in relevant animal models may help to elucidate them.

OBJECTIVE

To assess the effect of maternal anesthesia and surgery during pregnancy on the developing fetal brain, using a rabbit model.

MATERIALS AND METHODS

This is a randomized, sham-controlled study in time-mated pregnant does at 28 days of gestation (term = 31 days), which corresponds to the end of the second trimester in humans. Anesthesia was induced in 14 does (155 pups) with propofol and maintained with 4 vol% (equivalent to 1 minimum alveolar concentration) sevoflurane for 2 hours, and a laparotomy with minimal organ manipulation was performed (surgery group). Maternal vital signs (blood pressure, heart rate, peripheral and cerebral oxygen saturation, temperature, end-tidal CO₂, pH, lactate) were continuously monitored. Sham controls consisted of 7 does (74 pups) undergoing invasive hemodynamic monitoring for 2 hours without sedation. At term, does underwent cesarean delivery under ketamine-medetomidine sedation and local anesthesia. Pups either underwent motor and sensory neurologic testing followed by euthanasia at day 1 or daily neurodevelopment testing for 2 weeks and extensive neurologic assessment at 5 and 7 weeks (open field and object recognition test, T-maze, and radial-arm maze). Brains were harvested for histologic assessment of neuron density and synaptophysin expression.

RESULTS

Blood gases and vital parameters were stable in both groups. On postnatal day 1, surgery pups had significant lower motor (25 ± 1 vs 23 ± 3; P = .004) and sensory (16 ± 2 vs 15 ± 2; P = .005) neurobehavioral scores and lower brain-to-body weight ratios (3.7% ± 0.6% vs 3.4% ± 0.6%; P = .001). This was accompanied by lower neuron density in multiple brain regions (eg, hippocampus 2617 ± 410 vs 2053 ± 492 neurons/mm²; P = .004) with lower proliferation rates and less synaptophysin expression. Furthermore, surgery pups had delayed motor development during the first week of life, for example with hopping appearing later (6 ± 5 vs 12 ± 3 days; P = .011). Yet, by 7 weeks of age, neurobehavioral impairment was limited to a reduced digging behavior, and no differences in neuron density or synaptophysin expression were seen.

CONCLUSION

In rabbits, 2 hours of maternal general anesthesia and laparotomy, with minimal organ and no fetal manipulation, had a measurable impact on neonatal neurologic function and brain morphology. Pups had a slower motoric neurodevelopment, but by 7 weeks the effect became almost undetectable.