Maternal Temperature Research Articles

An Unexpected Cause of Recurrent Fetal Decelerations

An Unexpected Cause of Recurrent Fetal Decelerations

Maternal Fever Associated With Continuous Spinal Versus Epidural Labor Analgesia: A Single-Center Retrospective Study.

Neuraxial labor analgesia is associated with elevations in maternal temperature; the mechanism responsible is unknown. Proposed mechanisms have included infection, altered thermoregulation, and inflammation, potentially triggered by local anesthetics. Studies of the association between neuraxial labor analgesia and maternal fever have focused on epidural analgesia, and there have been no comparisons of the rate of maternal fever between continuous spinal and epidural labor analgesia. We performed a retrospective study to compare the rate of maternal fever between patients who received continuous spinal versus epidural labor analgesia between June 2012 and March 2020. Each patient who received continuous spinal analgesia was matched to 2 patients who received epidural analgesia and had the same nulliparous status. The primary outcome of our study was the incidence of intrapartum maternal fever, which we defined as any temperature ≥38 °C before delivery and compared between the continuous spinal and epidural groups using Fisher exact test. We identified 81 patients who received continuous spinal analgesia and 162 matched controls who received epidural analgesia. Demographic and obstetric characteristics of the patients were similar between groups. While the duration of analgesia did not significantly differ, there was markedly increased bupivacaine consumption in women with epidural analgesia. Eight of 81 (9.9%; 95% confidence interval [CI], 5.1-18.3) women with continuous spinal analgesia developed an intrapartum fever compared to 18 of 162 (11.1%; 95% CI, 7.1-16.9) of women with epidural analgesia ( P = .83; Fisher exact test). There was no significant difference in the rate of maternal fever between women with continuous spinal compared to epidural labor analgesia. While the route of administration and dose of bupivacaine differs between epidural and spinal labor analgesia, they are titrated to produce similar levels of neuraxial blockade. Our results are consistent with a model in which epidural related maternal fever is due to altered thermoregulation from a central neuraxial block and argue against a direct effect of bupivacaine or fentanyl, although we cannot rule out a concentration-independent effect of bupivacaine or fentanyl or an inflammatory effect of the catheter itself. These retrospective results highlight the importance of prospective and mechanistic study of neuraxial analgesia-related maternal fever.

Fetoscopic insufflation of heated-humidified carbon dioxide during simulated spina bifida repair is safe under controlled anesthesia in the fetal lamb.

To assess the safety of Partial-Amniotic-Insufflation-of-heated-humidified-CO2 (hPACI) during fetoscopic spina bifida repair (fSB-repair). A simulated fSB-repair through an exteriorized uterus under hPACI was performed in 100-day fetal lambs (term=145days) under a laboratory anesthesia protocol (n=5; group 1) which is known to induce maternal-fetal acidosis and hypercapnia. Since these may not occur clinically, we applied a clinical anesthesia protocol (n=5; group 2), keeping maternal parameters within physiological conditions, that is, controlled maternal arterial carbon dioxide (CO2) pressure (pCO2 =30mmHg), blood pressure (≥67mmHg), and temperature (37.1-39.8°C). Our superiority study used fetal pH as the primary outcome. Compared to group 1, controlled anesthesia normalized fetal pH (7.23±0.02 vs. 7.36±0.02, p<0.001), pCO2 (70.0±9.1 vs. 43.0±1.0mmHg, p=0.011) and bicarbonate (27.8±1.1 vs. 24.0±0.9mmol/L, p=0.071) at baseline. It kept them within clinically acceptable limits (pH≥7.23, pCO2 ≤70mmHg, bicarbonate≤30mm/L) for ≥120min of hPACI as opposed to ≤30min in group one. Fetal pO2 and lactate were comparable between groups and generally within normal range. Fetal brain histology demonstrated fewer apoptotic cells and higher neuronal density in the prefrontal cortex in group two. There was no difference in fetal membrane inflammation, which was mild. Fetoscopic insufflation of heated-humidified CO2 during simulated fSB-repair through an exteriorized uterus can be done safely under controlled anesthesia.

The thermal consequences of primate birth hour and its evolutionary implications.

Most primates, including humans, give birth during the inactive phase of the daily cycle. Practical constraints therefore limit our knowledge of the precise timing of nocturnal birth in wild diurnal primates and so limit our understanding of selective pressures and consequences. We measured maternal core body temperature (Tb) across 24 births in a population of wild vervet monkeys using biologgers. We identified distinct perturbations in Tb during the birth period, including declining Tb during labour and the rapid recovery of Tb post-parturition. Vervet monkeys typically gave birth during their inactive phase in synchrony with the nadir of the maternal nychthemeral Tb rhythm but also showed remarkable inter-individual variability in their absolute Tb during birth. Our findings support the view that selection may have favoured a nocturnal timing of primate birth to coincide with lower night-time Tb and environmental temperatures, which improve thermal efficiency during birth.

Maternal Apparent Temperature During Pregnancy on the Risk of Offspring Asthma and Wheezing: Effect, Critical Window, And Modifiers

Maternal Apparent Temperature During Pregnancy on the Risk of Offspring Asthma and Wheezing: Effect, Critical Window, And Modifiers

Management of Isolated Fever in Labour Compared with Clinical Chorioamnionitis in a Quaternary Centre

To investigate treatment patterns of women with isolated fever in labour and evaluate if variables in the sepsis in obstetrics score (SOS) or fetal tachycardia are associated with treatment differences. Our secondary objective was to compare women with isolated fever in labour with women with clinical chorioamnionitis to identify any clinicodemographic differences. A retrospective cohort study of 473 patients at BC Women's Hospital who presented with isolated fever in labour between January 2011 and April 2016 compared with a dataset of 1135 women with clinical chorioamnionitis from 2011 to 2016 in the same institution. In our cohort of isolated fever in labour, antibiotics were given 74.2 % of the time, and the majority received cefazolin and metronidazole (80.9%, of those who received antibiotics). Higher maternal temperature and heart rate at time of first fever and fetal tachycardia were associated with more antibiotic use. Slightly higher maternal temperature was associated with use of a saline bolus and blood cultures. The proportion of women with a SOS greater than 5 increased 4.5-fold from time of first fever to time of maximum SOS. There were fewer cesarean deliveries in the isolated fever in labour group compared with the clinical chorioamnionitis group (22.4% vs. 54.0%; P < 0.0001). Slightly higher maternal temperature was associated with increased treatment, including antibiotic use, saline bolus administration, and blood cultures. As evidenced by the higher proportion of women with an SOS over 5, women with isolated fever in labour may have a propensity to deteriorate clinically.

Effectiveness of Combined Strategies for the Prevention of Hypothermia Measured by Noninvasive Zero-Heat Flux Thermometer During Cesarean Section.

Background: Perioperative hypothermia (body temperature <36°C) is a common complication of anesthesia increasing the risk for maternal cardiovascular events and coagulative disorders, and can also influence neonatal health. The aim of our work was to evaluate the impact of combined warming strategies on maternal core temperature, measured with the SpotOn. We hypothesized that combined modalities of active warming prevent hypothermia in pregnant women undergoing cesarean delivery with spinal anesthesia.Methods: Seventy-eight pregnant women were randomly allocated into three study groups receiving warmed IV fluids and forced-air warming (AW), warmed IV fluids (WF), or no warming (NW). Noninvasive core temperature device (SpotOn) measured maternal core temperature intraoperatively and for 30 min after surgery. Maternal mean arterial pressure, incidence of shivering, thermal comfort and newborn's APGAR, axillary temperature, weight, and blood gas analysis were also recorded.Results: Incidence of hypothermia was of 0% in AW, 4% in WF, and 47% in NW. Core temperature in AW was constantly higher than WF and NW groups. Incidence of shivering in perioperative time was significantly lower in AW and WF groups compared with the NW group (p < 0.04). Thermal comfort was higher in both AW and WF groups compared with NW group (p = 0.02 and p = 0.008, respectively). There were no significant differences among groups for the other evaluated parameters.Conclusion: Combined modalities of active warming are effective in preventing perioperative hypothermia. The routine uses of combined AW are suggested in the setting of cesarean delivery.

Self-assessment

You attend the delivery of a baby born by spontaneous onset normal vaginal delivery at 34+3 weeks gestation. The baby is born in good condition but develops increased work of breathing at a few minutes of life. Antenatal scans and serology were unremarkable except for polyhydramnios. There was no prolonged rupture of membranes or maternal temperature and maternal GBS status was negative. The mother was given one dose of antenatal steroids.

Epidural fever.

Epidural analgesia (EPA) is the most effective method of intrapartum pain relief and is considered to be very safe. Recently, it has been used in up to 34% of parturients with EPA and is also associated with maternal temperature elevations during labor. The mechanism of this epidural-associated fever remains incompletely understood. The most likely etiology seems to be non-infectious inflammation caused by an epidural catheter. However, some authors deny this association. They theorize it is caused by selection bias only, as EPA is more often required by women with more painful and prolonged or more complicated labor, where temperature elevation is due to other causes. They point out that in some studies, fever was correlated to EPA only with concurrent placental inflammation. Maternal fever, despite the cause, either infectious or non-infectious origin, carries important clinical and public health implications. Further research that evaluates maternal epidural status and its influence on maternal or neonatal fever could improve sepsis evaluation and lead to worldwide decrease of unnecessary antibio-tic exposure.

Association between preoperative toe perfusion index and maternal core temperature decrease during cesarean delivery under spinal anesthesia: a prospective cohort study

BackgroundThe main mechanism of body temperature decrease during cesarean delivery under spinal anesthesia is core-to-peripheral redistribution of body heat, attributable to vasodilation. Perfusion index (PI) obtained with a pulse oximeter helps to assess peripheral perfusion dynamics by detecting the change in peripheral vascular tone. This study aimed to examine whether preoperative toe PI could predict the decrease in core temperature induced by spinal anesthesia during cesarean delivery.MethodsParturients undergoing scheduled cesarean delivery under combined spinal-epidural anesthesia from September 2019 to March 2020 were enrolled in this single-center prospective cohort study. All parturients received 0.5% hyperbaric bupivacaine (10 mg) with fentanyl (15 μg) intrathecally. A pulse oximeter probe was placed on the left second toe for continuous PI measurement. The 3 M™ Bair Hugger™ Temperature Monitoring System placed over the right temporal region was used to record core temperature over time. We evaluated the association between the maximum core temperature decrease, which is the primary outcome, and the preoperative toe PI at operating room (OR) admission using a segmented regression model (SRM) and a generalized additive model (GAM). The maximum core temperature decrease was defined as the difference between core temperature at OR admission and minimum intraoperative core temperature.ResultsForty-eight patients were evaluated. In the SRM, the slope for the association between the maximum core temperature decrease and the preoperative toe PI changed from 0.031 to 0.124 after PI = 2.4%. Likewise, with the GAM, there was a small core temperature decrease when preoperative toe PI was greater than 2.0 to 3.0%.ConclusionsLow preoperative toe PI was associated with maternal core temperature decrease during cesarean delivery under spinal anesthesia. Preoperative toe PI is a simple, non-invasive, and effective tool for the early prediction of perioperative core temperature decrease during cesarean delivery.Trial registrationUMIN Clinical Trials Registry (registry number: UMIN000037965).

Separating Paternal and Maternal Contributions to Thermal Transgenerational Plasticity

Climate change is rapidly altering the thermal environment in terrestrial and aquatic systems. Transgenerational thermal plasticity (TGP) – which occurs when the temperatures experienced by the parental generation prior to the fertilization of gametes results in a change in offspring reaction norms – may mitigate the effects of climate change. Although “maternal effects” have been widely studied, relatively little is known about TGP effects in vertebrates, particularly paternal contributions. We used artificial fertilization to cross sheepshead minnow (Cyprinodon variegatus) parents exposed to either low (26°C) or high (32°C) temperatures and measured growth rates of the offspring over the first 8 weeks of life at both low and high temperatures. A linear mixed effects model was employed to quantify the effects of maternal, paternal, and offspring temperatures on offspring growth and fecundity. We found that the offspring growth rate up to 63 days post-hatch was affected by both the temperature they experienced directly and parental temperatures prior to fertilization. Growth was lowest when neither parents’ temperature matched the offspring temperature, indicating a strong transgenerational effect. Notably, offspring growth was highest when all three (offspring, sire, and dam) temperatures matched [although the three-way interaction was found to be marginally non-significant (P = 0.155)], suggesting that TGP effects were additive across significant sire-offspring (P &amp;lt; 0.001) and dam-offspring interactions (P &amp;lt; 0.001). Transgenerational effects on fecundity (GSI) were suggestive for both maternal and paternal effects, but not significant. The finding that thermal TGP is contributed by both parents strongly suggests that it has an epigenetic basis.

Prenatal ambient temperature and risk for schizophrenia

ObjectiveWe conducted a systematic review of the published literature to test the hypothesis that maternal exposure to extremes of ambient temperatures during pregnancy is associated with the risk for psychiatric disorders or congenital malformations in offspring, both of which are indicative of perturbations of fetal neurodevelopment. MethodThis study was conducted in accordance with the recommendations outlined in the Meta-analysis of Observational Studies in Epidemiology (MOOSE) reporting proposal.Electronic databases (Ovid MEDLINE, Ovid Embase, Ovid PsycINFO, Ovid Global Health, Web of Science, and Cochrane Library) were searched. Four independent reviewers selected studies with the following criteria: (1) prenatal maternal ambient temperature exposure; (2) outcome of offspring psychiatric disorder or congenital defects; (3) empirical study; (4) full-length article, no conference presentations or abstracts. ResultsTwenty-two studies met criteria and one was added from a reference list (n = 23). Of these, schizophrenia (n = 5), anorexia nervosa (n = 3) and congenital cardiovascular malformations (n = 6) studies were the most common. Each of these categories showed some evidence of association with an early pregnancy maternal ambient heat exposure effect, with other evidence for a late pregnancy cold effect. ConclusionSome evidence supports a role for early pregnancy maternal exposure to extreme ambient heat in the development of psychiatric disorders, but large-scale, prospective cohort data on individual births is essential. Optimal studies will be conducted in seasonally variable climates, accounting for actual maternal residence over the pregnancy and at parturition, local environmental temperature records, and appropriate covariates, similar to studies identified by this systematic review for congenital malformations.

Effects of altered climates on American ginseng population dynamics

AbstractAs climates change, species with locally adapted populations may be particularly vulnerable as specialization narrows the range of conditions under which populations can persist. Populations adapted to local climate as well as other site‐specific characteristics like soils present challenges for inferring how changing climates affect fitness, as climatic and nonclimatic variables that constitute local conditions decouple. We conducted two transplant experiments involving American ginseng to test how climatic conditions affect performance while controlling for effects of other site characteristics. We first out‐planted populations from differing elevations to gardens arrayed along an elevation/climate gradient. We also grew maternal plants under temperatures corresponding to home‐site and future conditions (16.4–22.4°C), transplanting resultant progeny to two home‐sites at different elevations (400 m, 800 m). Source populations responded idiosyncratically to elevation reflecting how nonclimatic site characteristics strongly affected plant fitness. Germination rates declined for seeds from maternal plants exposed to warmer temperatures, which compounded with diminished seed production of maternal plants, suggested that population growth may decline rapidly as warm years become hotter and more frequent. Controlling for maternal temperature effects provided evidence that plants are adapted to home‐site conditions, both climatic and nonclimatic, with population growth rates for out‐planted populations ranging from below population replacement levels (λ = 0.58) to well above (λ = 1.33). Evidence of local adaptation to climatic and nonclimatic environmental components, in combination with negative fitness impacts of warming climates on offspring via maternal effects, suggests that changing climate may imperil ginseng and other similar understory species.

Ambient air pollution, psychological stress, and early childhood respiratory outcomes: Modifying effects of prenatal maternal diet, sex, and race/ethnicity

BACKGROUND AND AIM: Many lower income, racially/ethnically mixed communities experience co-occurring environmental hazards (i.e., pollutants, social inequities and related stress, poorer access to healthy foods) contributing to respiratory disease. Starting {in utero}, fine particulate matter (PM₂.₅) and stress disrupt similar but not completely overlapping processes, including oxidative stress, influencing respiratory health. Antioxidant intake can have protective effects. We examined associations among prenatal PM₂.₅, maternal stress, and antioxidant intake in relation to early childhood wheeze in a longitudinal pregnancy cohort in the Northeastern United States (N=539). METHODS: Daily prenatal PM₂.₅ exposure was estimated using a satellite-based spatiotemporally resolved model. Women completed the Lifetime Stressor Checklist-Revised (LSC-R). A prenatal antioxidant index (AI) was based on average percentile intake of beta-carotene, vitamins (A,C,E), zinc, magnesium, and selenium. Mothers reported child wheeze with follow-up to 4.1±2.8 years. Logistic regression was used to examine effects of prenatal AI and LSC-R on repeated wheeze (≥2 episodes); effect modification was explored in stratified models. Bayesian distributed lag interaction models (BDLIMs) were used to examine associations between prenatal PM₂.₅ exposure on wheeze, and effect modification by AI, race/ethnicity, and child sex. Covariates included maternal age, education, asthma, and temperature. RESULTS:Women were 39.3% black and 33% Hispanic with 35.6% reporting ≤high school education; 20.3% of children had repeated wheeze. The association between higher AI and decreased wheeze was significant only in blacks (Odds Ratio, OR=0.37, 95% confidence interval, CI: 0.19-0.73 per interquartile range increase). Higher stress was associated with repeated wheeze when AI was below the median, especially among blacks/Hispanics [OR=1.04 (1.01-1.06)]. BDLIMs found that cumulative effect on repeated wheeze per μg/m³ increase in PM₂.₅ across pregnancy was only significant in boys born to black mothers with low antioxidant intake [OR=1.2 (1.01-1.59)]. CONCLUSIONS:Relationships among prenatal PM₂.₅, stress, antioxidant intake, and child wheeze are complex and are modified by race/ethnicity and child sex. KEYWORDS: particulate matter, prenatal stress, nutrition, antioxidants, pediatric respiratory outcomes

Queen honey bees exhibit variable resilience to temperature stress.

Extreme temperature exposure can reduce stored sperm viability within queen honey bees; however, little is known about how thermal stress may directly impact queen performance or other maternal quality metrics. Here, in a blind field trial, we recorded laying pattern, queen mass, and average callow worker mass before and after exposing queens to a cold temperature (4°C, 2 h), hot temperature (42°C, 2 h), and hive temperature (33°C, control). We measured sperm viability at experiment termination, and investigated potential vertical effects of maternal temperature stress on embryos using proteomics. We found that cold stress, but not heat stress, reduced stored sperm viability; however, we found no significant effect of temperature stress on any other recorded metrics (queen mass, average callow worker mass, laying patterns, the egg proteome, and queen spermathecal fluid proteome). Previously determined candidate heat and cold stress biomarkers were not differentially expressed in stressed queens, indicating that these markers only have short-term post-stress diagnostic utility. Combined with variable sperm viability responses to temperature stress reported in different studies, these data also suggest that there is substantial variation in temperature tolerance, with respect to impacts on fertility, amongst queens. Future research should aim to quantify the variation and heritability of temperature tolerance, particularly heat, in different populations of queens in an effort to promote queen resilience.

Effect of transcutaneous electrical acupoint stimulation on epidural-related maternal fever in parturients undergoing epidural labor analgesia

To evaluate the therapeutic effect and safety of transcutaneous electrical acupoint stimulation (TEAS) on epidural-related maternal fever in parturients undergoing epidural labor analgesia. A total of 198 primiparas with single birth, full-term pregnancy and head position were recruited and randomized into a TEAS group (98 cases) and a control group (100 cases). In the TEAS group, after epidural labor analgesia, TEAS was applied to bilateral Hegu (LI4) and Quchi (LI11), once an hour, for 30 min each time, till the end of childbirth. In the control group, after epidural labor analgesia, TEAS electrodes were attached to the same acupoints, but without electric stimulation. Maternal tympanic temperature and the score of Visual Analogue Score (VAS) were measured before analgesia, at 1, 2, 3, 4 and 5 h after analgesia and during labor respectively and maternal fever rate was evaluated in the parturients of two groups. Separately, before analgesia, 2 h after analgesia and during labor, the levels of serum interleukin (IL-6) and IL-1β were determined in the parturients of two groups. The duration of labor, the mode of labor, oxytocin dosage, postpartum hemorrhage, neonatal Apgar scores, time of labor analgesia, labor analgesic consumption and adverse effects were recorded in the parturients of two groups. Maternal tympanic temperature increased progressively in two groups as analgesic time prolonged. Tympanic temperature at 3, 4 and 5 h after analgesia and du-ring labor, and maternal fever rate during labor in the TEAS group were all lower than those in the control group respectively (P<0.05). The levels of serum IL-6 and IL-1β increased after analgesia in the parturients of two groups. The serum IL-6 level during labor and the level of IL-1β at 2 h after analgesia and during labor in the parturients of the TEAS group were lower than those in the control group (P<0.05). The analgesic consumption in the TEAS group was less than that in the control group (P<0.05). The incidence of chills in the TEAS group was lower than that in the control group (P<0.05). The differences were not statistical in VAS score, duration of labor, mode of labor, oxytocin dosage, postpartum hemorrhage, time of labor analgesia and neonatal Apgar score, as well as the incidence of urine retention, nausea and vomiting and urinary retention between two groups (P>0.05). Transcutaneous electrical acupoint stimulation at LI11 and LI4 is conductive to relieving epidural-rela-ted maternal fever and reducing serum levels of IL-6 and IL-1β in the parturients undergoing epidural labor analgesia. It is safe and effective in clinical application.

Effect of Temperature and Maternal Age on Recombination Rate in Cattle.

Meiotic recombination is a fundamental biological process that facilitates meiotic division and promotes genetic diversity. Recombination is phenotypically plastic and affected by both intrinsic and extrinsic factors. The effect of maternal age on recombination rates has been characterized in a wide range of species, but the effect’s direction remains inconclusive. Additionally, the characterization of temperature effects on recombination has been limited to model organisms. Here we seek to comprehensively determine the impact of genetic and environmental factors on recombination rate in dairy cattle. Using a large cattle pedigree, we identified maternal recombination events within 305,545 three-generation families. By comparing recombination rate between parents of different ages, we found a quadratic trend between maternal age and recombination rate in cattle. In contrast to either an increasing or decreasing trend in humans, cattle recombination rate decreased with maternal age until 65 months and then increased afterward. Combining recombination data with temperature information from public databases, we found a positive correlation between environmental temperature during fetal development of offspring and recombination rate in female parents. Finally, we fitted a full recombination rate model on all related factors, including genetics, maternal age, and environmental temperatures. Based on the final model, we confirmed the effect of maternal age and environmental temperature during fetal development of offspring on recombination rate with an estimated heritability of 10% (SE = 0.03) in cattle. Collectively, we characterized the maternal age and temperature effects on recombination rate and suggested the adaptation of meiotic recombination to environmental stimuli in cattle. Our results provided first-hand information regarding the plastic nature of meiotic recombination in a mammalian species.

Maternal cold exposure induces distinct transcriptome changes in the placenta and fetal brown adipose tissue in mice

BackgroundBrown adipose tissue (BAT) is specialized to dissipate energy in the form of heat. BAT-mediated heat production in rodents and humans is critical for effective temperature adaptation of newborns to the extrauterine environment immediately after birth. However, very little is known about whether and how fetal BAT development is modulated in-utero in response to changes in maternal thermal environment during pregnancy. Using BL6 mice, we evaluated the impact of different maternal environmental temperatures (28 °C and 18 °C) on the transcriptome of the placenta and fetal BAT to test if maternal cold exposure influences fetal BAT development via placental remodeling.ResultsMaternal weight gain during pregnancy, the average number of fetuses per pregnancy, and placental weight did not differ between the groups at 28 °C and 18 °C. However, the average fetal weight at E18.5 was 6% lower in the 18 °C-group compared to the 28 °C-group. In fetal BATs, cold exposure during pregnancy induced increased expression of genes involved in de novo lipogenesis and lipid metabolism while decreasing the expression of genes associated with muscle cell differentiation, thus suggesting that maternal cold exposure may promote fetal brown adipogenesis by suppressing the myogenic lineage in bidirectional progenitors. In placental tissues, maternal cold exposure was associated with upregulation of genes involved in complement activation and downregulation of genes related to muscle contraction and actin-myosin filament sliding. These changes may coordinate placental adaptation to maternal cold exposure, potentially by protecting against cold stress-induced inflammatory damage and modulating the vascular and extravascular contractile system in the placenta.ConclusionsThese findings provide evidence that environmental cold temperature sensed by the mother can modulate the transcriptome of placental and fetal BAT tissues. The ramifications of the observed gene expression changes warrant future investigation.

Fetal heart rate monitoring during fetoscopic repair of open spinal neural tube defects: a single-centre observational cohort study

BackgroundDuring fetal surgery, the haemodynamic stability of the fetus depends on the haemodynamic stability of the mother. The primary objective of this study was to assess changes in fetal heart rate (FHR) throughout the different stages of surgery. The secondary objective was to assess potential changes in maternal physiological parameters and their association with FHR. MethodsThis was a single-center observational cohort study conducted between 2015 and 2019 in 26 women undergoing intra-uterine fetoscopic repair of open spina bifida. The primary outcome was FHR. Maternal physiologic parameters were measured at the beginning, during and after surgery. The linear mixed-effects model fitted by maximum likelihood was used to assess changes in each variable at specific times throughout the surgery, and the repeated measures correlation coefficient was used to study the association between FHR and maternal physiological parameters. ResultsOne (3.8%) case of fetal bradycardia (FHR <110 beats per minute) required the administration of intramuscular atropine. No other significant FHR changes were observed during surgery. Maternal oesophageal temperature (P <0.001), lactate levels (P=0.002), and mean arterial pressure (P=0.016) changed significantly during surgery, although none of these changes was clinically relevant. The FHR showed a significant association with maternal carbon dioxide tension (r=0.285, 95% CI 0.001 to 0.526) and maternal heart rate (r=0.302, 95% CI 0.025 to 0.535). ConclusionThe FHR remained stable during intra-uterine fetoscopic repair of open spina bifida. Maternal carbon dioxide tension and heart rate may have a mild influence on FHR.

The impact of peak and duration of maternal intrapartum fever on perinatal outcomes

Intrapartum fever is a common perinatal complication, associated with short- and long-term adverse outcomes. Limited data exist regarding the association between the peak and duration of maternal fever and the extent and severity of maternal and neonatal complications. This study aimed to examine the association between maternal intrapartum fever peak and duration and perinatal outcomes. A retrospective cohort analysis of term singleton live births in 2 medical centers between the years 2003 and 2015 was conducted. The study group included parturients who experienced intrapartum fever, defined as a temperature of ≥38.0°C (100.4°F). Fever duration was defined as the time elapsed between the first documented fever and subsequent first documented normal body temperature (<38°C or <100.4°F) or if the temperature did not return to normal until delivery. Adjusted risks for adverse perinatal outcomes were calculated using multiple logistic regression models to control for confounders. A cohort study of 85,713 deliveries was analyzed, of which 1517 (1.8%) parturients experienced fever during delivery. Adverse composite neonatal outcome gradually worsens, in a dose-response manner, with higher maximal maternal temperature. Similar dose-response deterioration was found when maximal parturient temperature was combined with fever duration (P=.015). Higher or longer maternal fever was not independently associated with cesarean or instrumental deliveries (P=.648). Duration alone was not significantly associated with worsening neonatal outcomes (P=.711). Maximal intrapartum maternal fever, solely and when combined with fever duration, is correlated with neonatal complications in a dose-dependent manner. Further prospective studies are needed to examine the potential benefit of rigorous maternal body temperature control on perinatal outcomes.