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Introduction: Transverse relaxation time (T2*) is related to tissue oxygenation and morphology. We aimed to describe T2* weighted MRI in selected fetal organs in normal pregnancies, and to investigate the correlation between fetal organ T2* and placental T2*, birthweight (BW) deviation, and redistribution of fetal blood flow. Methods: T2*-weighted MRI was performed in 126 singleton pregnancies between 23+6- and 41+3-weeks’ gestation. The T2* value was obtained from the placenta and fetal organs (brain, lungs, heart, liver, kidneys, and spleen). In normal BW pregnancies (BW > 10th centile), the correlation between the T2* value and gestational age (GA) at MRI was estimated by linear regression. The correlation between fetal organ Z-score and BW group was demonstrated by boxplots and investigated by analysis of variance (ANOVA) for each organ. Results: In normal BW pregnancies fetal organ T2* was negatively correlated with GA. We found a significant correlation between BW group and fetal organ T2* z-score in the fetal heart, kidney, lung and spleen. A positive linear correlation was demonstrated between fetal organ T2* and outcomes related to placental function such as BW deviation and placenta T2* in all investigated fetal organs except for the fetal liver. In the fetal heart, kidneys, and spleen the T2* value showed a significant correlation with fetal redistribution of blood flow (Middle cerebral artery Pulsatility Index) before delivery. Discussion: Fetal T2* is correlated with BW, placental function, and redistribution of fetal blood flow, suggesting that fetal organ T2* reflects fetal oxygenation and morphological changes related to placental dysfunction.

Introduction Maternal pregestational obesity is a significant risk factor for adverse pregnancy outcomes, such as gestational diabetes. Both these conditions can have an impact on placental development and affect maternal-fetal exchanges, compromising fetal metabolic status. The aim of the study is to investigate the influence of pre-pregnancy BMI on placental size and to evaluate the role of obesity and gestational diabetes mellitus (GDM) on fetal oxygenation in overweight and obese pregnant women. Methods 208 normal weight (NW), 57 overweight (OW) and 69 obese (OB) women were studied at elective cesarean section (CS) at term. 10 OW and 24 OB women were affected by GDM. Maternal, fetal and placental data were collected. Respiratory gases and acid-base balance were measured in umbilical venous and arterial blood. Results Placental weight and thickness were higher in OB pregnancies. Lower fetal-placental ratios (F/P) were found in GDM pregnancies, both OW and OB. Fetuses from OB mothers were more hypoxic and acidemic compared to NW, particularly when complicated by GDM. Discussion In agreement with previous studies, our data show that placentas from OB and GDM pregnancies are heavier and thicker, suggesting that an unbalanced pregestational nutritional status can decrease the placental efficiency in maternal-fetal exchanges. Fetuses from obese women are also hypoxic and acidemic, while fetuses from gestational diabetic mothers are hypoxic, reflecting that an altered pre-pregnancy BMI can affect fetal oxygenation, and GDM can play an additional detrimental role, thus worsening placental function and fetal oxygenation.

Este artículo se encuentra disponible en la página web de la revista en la siguiente URL: https://journals.physiology.org/doi/full/10.1152/japplphysiol.00303.2019?rfr_dat=cr_pub++0pubmed&url_ver=Z39.88-2003&rfr_id=ori%3Arid%3Acrossref.org This is the pre-peer reviewed version of the following article: Almendros, I., Martínez-Ros, P., Farré, N., Rubio-Zaragoza, M., Torres, M., Gutiérrez-Bautista, A.J. et al. (2019). Placental oxygen transfer reduces hypoxia-reoxygenation swings in fetal blood in a sheep model of gestational sleep apnea. Journal of Applied Physiology, vol. 127, i. 3 (13 sep.), pp. 745-752, which has been published in final form at https://doi.org/10.1152/japplphysiol.00303.2019. Este es el pre-print del siguiente artículo: Almendros, I., Martínez-Ros, P., Farré, N., Rubio-Zaragoza, M., Torres, M., Gutiérrez-Bautista, A.J. et al. (2019). Placental oxygen transfer reduces hypoxia-reoxygenation swings in fetal blood in a sheep model of gestational sleep apnea. Journal of Applied Physiology, vol. 127, i. 3 (13 sep.), pp. 745-752, que se ha publicado de forma definitiva en https://doi.org/10.1152/japplphysiol.00303.2019. AIM: Obstructive sleep apnea (OSA), characterized by events of hypoxia reoxygenation, is highly prevalent in pregnancy, negatively affecting the gestation process and particularly the fetus. Whether the consequences of OSA on the fetus and offspring are mainly caused by systemic alterations in the mother or by direct effect of intermittent hypoxia in the fetus is unknown. In fact, how apnea-induced hypoxemic swings in OSA are transmitted across the placenta remains to be investigated. The aim of this study was to test the hypothesis, based on a theoretical background on the dampening effect of oxygen transfer in the placenta, that oxygen partial pressure (PO2) swings resulting from obstructive apneas mimicking OSA are mitigated in the fetal circulation. METHODS: To this end, 4 anesthetized ewes close to term pregnancy were subjected to obstructive apneas consisting of 25-s airway obstructions. Real time PO2 was measured in the maternal carotid artery and in the umbilical vein using fast-response fiberoptic oxygen sensors. RESULTS: The amplitude of PO2 swings in the umbilical vein were considerably smaller (3.1±1.0 vs. 21.0±6.1 mmHg (m±SE); p

Observing fetal development in utero is vital to further the understanding of later-life diseases. Magnetic resonance imaging (MRI) offers a tool for obtaining a wealth of information about fetal growth, development, and programming not previously available using other methods. This review provides an overview of MRI techniques used to investigate the metabolic and cardiovascular consequences of the developmental origins of health and disease (DOHaD) hypothesis. These methods add to the understanding of the developing fetus by examining fetal growth and organ development, adipose tissue and body composition, fetal oximetry, placental microstructure, diffusion, perfusion, flow, and metabolism. MRI assessment of fetal growth, organ development, metabolism, and the amount of fetal adipose tissue could give early indicators of abnormal fetal development. Noninvasive fetal oximetry can accurately measure placental and fetal oxygenation, which improves current knowledge on placental function. Additionally, measuring deficiencies in the placenta’s transport of nutrients and oxygen is critical for optimizing treatment. Overall, the detailed structural and functional information provided by MRI is valuable in guiding future investigations of DOHaD.

High incidences of pre-weaning mortality continue to limit global sheep production, constituting a major economic and welfare concern. Despite significant advances in genetics, nutrition, and management, the proportion of lamb deaths has remained stable at 15–20% over the past four decades. There is mounting evidence that melatonin can improve outcomes in compromised ovine pregnancies via enhanced uterine bloodflow and neonatal neuroprotection. This review provides an overview of the major risk factors and underlying mechanisms involved in perinatal lamb mortality and discusses the potential of melatonin treatment as a remedial strategy. Supplementing pregnant ewes with melatonin enhances uterine bloodflow and fetal oxygenation, and potentially birthweight and neonatal thermogenic capacity. Melatonin freely crosses the ovine placenta and blood-brain barrier and provides neuroprotection to the fetal lamb during periods of chronic and acute hypoxia throughout gestation, with improved behavioural outcomes in hypoxic neonates. The current literature provides strong evidence that maternal melatonin treatment improves outcomes for lambs which experience compromised in utero development or prolonged parturition, though to date this has not been investigated in livestock production systems. As such there is a clear basis for continued research into the effects of maternal melatonin supplementation during gestation on pre-weaning survival under extensive production conditions.

Background There is a need for pediatric medical devices that accommodate the unique physiology and anatomy of pediatric patients that is increasingly receiving more attention. However, there is limited literature on the programs within children's hospitals and academia that can support pediatric device development. We describe our experience with pediatric device design utilizing collaborations between a children's hospital and two engineering schools. Methods Utilizing the academic year as a timeline, unmet pediatric device needs were identified by surgical faculty and matched with an engineering mentor and a team of students within the Capstone Engineering Design programs at two universities. The final prototypes were showcased at the end of the academic year and if appropriate, provisional patent applications were filed. Results All twelve teams successfully developed device prototypes, and five teams obtained provisional patents. The prototypes that obtained provisional patents included a non-operative ureteral stent removal system, an evacuation device for small kidney stone fragments, a mechanical leech, an anchoring system of the chorio-amniotic membranes during fetal surgery, and a fetal oxygenation monitor during fetoscopic procedures. Conclusions Capstone Engineering Design programs in partnership with surgical faculty at children's hospitals can play an effective role in the prototype development of novel pediatric medical devices. Levels of evidence N/A – No clinical subjects or human testing was performed.

Oxytocin is one of the most commonly used medications in obstetrics and has been associated with claims of negligence in cases of adverse outcomes. Errors involving intravenous oxytocin administration for induction or augmentation of labor are most commonly dose related and include failure to avoid or treat tachysystole or failure to asses or treat a fetal heart rate pattern indicative of disruption in oxygenation. Clinicians should be knowledgeable regarding pharmacokinetics of oxytocin and the effect of uterine contractions on fetal oxygenation as well as safe titration of oxytocin to achieve the desired effect while minimizing harm.

Every year, about 85 percent of the approximately 5 million births in North America are evaluated with the electronic fetal monitoring (EFM). Clinicians use the EFM as a proxy to assess fetal oxygenation status, fetal well-being, and potential compromise. Despite the widespread use of this technology, neonatal hypoxia and acidosis continue to make up a high proportion of neonatal morbidity at term. Indeed, though the fetal heart rhythm is inextricably linked to fetal acid-base status, EFM has not been shown to reliably predict neonatal pH status nor has it reduced adverse maternal or neonatal outcomes. As a consequence, the high false-positive rate of EFM for predicting adverse neonatal outcomes has led to an increase in the rate of operative vaginal and cesarean delivery, with elevated rates of associated maternal and neonatal morbidity. This fact invariably leads to a paradox we have henceforth defined as the “obstetrical paradox.” Herein, we explore the potential solutions to this paradox and introduce a novel noninvasive technique to assess fetal acid-base status in utero known as the “FETAL technique” (Fourier Evaluation of Tracings and Acidosis in Labour). The FETAL technique, currently under investigation, applies the discrete Fourier transformation to EFM tracings to determine the spectral frequency distribution of the fetal heart rate. These specific frequency distributions correlate with specific umbilical pH values and may provide the missing link between fetal heat rate patterns and acid-base status at birth. As we work toward realizing the full potential benefits of EFM, finding the best assessment strategies to evaluate fetal pH in real time remains a key goal in obstetrics.

We compared the association between cord arterial catecholamine levels and fetal oxygenation in newborns of mothers with diabetes mellitus to those of nondiabetic pregnancies.Cord blood obtained at delivery in 25 term appropriate-for-gestational age newborns of women with diabetes and 27 nondiabetic controls were assayed for norepinephrine, epinephrine, insulin, glucose, and blood gases.There was no statistical difference in parity, birth weight, gestational age, delivery mode, use of epidural analgesia, or frequency of low 1-min Apgar scores between the groups. The pOThe expected surge in catecholamines associated with diminished oxygenation was attenuated in fetuses of diabetic mothers. This suggests the possibility that fetal exposure to hyperglycemia or other metabolic derangements in pregnant diabetics might compromise the fetal ability to adapt to changes in oxygenation, and might thereby contribute to the risk of fetal death.

Fetal heart activity is a vital measurement to assess the well-being of fetus throughout its intrauterine lifetime and mostly at the time of delivery. As it is a fact that the fetal heart rate interpretations are done manually, the readings are highly inaccurate and found to be subjective. Automated CTG analysis has been adopted as the most capable way to handle these problems of CTG. In this scope, CTG-OAS, an open software is used for fetal heart rate analysis. This software analyses the fetal heart rate and extracts the features of heart rate variability for further analysis. The results obtained are validated with those derived from the pH values of the cortical blood samples of delivered babies. The sympathetic and parasympathetic control on fetal heart rate and its relation with the fetal oxygenation is studied and analyzed for early detection of fetal distress.

Background: Stress of labor pain disturbs the maternal autonomic functions and liberates catecholamines which predisposes to dysfunctional labor and compromise fetal oxygenation. Freedom from pain improves the environment for both mother and fetus and therapy improves obstetric outcome. The objective of the study was to evaluate the efficacy of programmed labor protocol in providing shorter, safer and relatively pain free deliveries. Methods: 100 primigravidae with term pregnancy (37-41 wks) meeting inclusion criteria were enrolled in the study. Alternate women were allocated to two groups-study group (50) and control group (50). Programmed labor protocol was initiated in study group and control group were managed expectantly as per hospital protocol. Feto maternal outcome variables were noted. Results: In study group there was a marked reduction of the active phase of labor. The mean duration of cervical dilatation was nearly double (2.3+/-0.3 cm/hr) than the control group (1.2+/-0.4cm/hr) resulting in shortening of the duration of both first as well as second stage in the study group. In the study there was 66% of women has good pain relief 20% of women has moderate pain relief. No neonatal mortality or life threatening complications were seen in both the groups. Conclusions: Programmed labor protocol can be used by all clinicians with high benefit and safety margin.

This article focuses on themajor aspects of the physiology of oxygen supply to the fetus and the main goals of intrapartum fetal monitoring: (1) timely identification of fetuses that are being inadequately oxygenated, to enable appropriate action before the occurrence of injury; and (2) reassurance on adequate fetal oxygenation to avoid unnecessary obstetric interventions. It should be emphasized that to avoid adverse outcome, fetal surveillance requires a timely clinical response and the ready availability of both adequate equipment and trained staff in intrapartum care.

Accurate analysis of placental and fetal oxygenation is critical during pregnancy. Photoacoustic imaging (PAI) combines laser technology with ultrasound in real time. We tested the sensitivity and accuracy of PAI for analysis of placental and fetal oxygen saturation (sO2) in mice. The placental labyrinth (L) had a higher sO2 than the junctional zone plus decidua region (JZ+D) in C57Bl/6 mice. Changing maternal O2 from 100 to 20% in C57Bl/6 mice lowered sO2 in these regions. C57Bl/6 mice were treated with the NO synthase inhibitor L-NG-nitroarginine methyl ester (L-NAME) from gestational day (GD) 11 to GD18 to induce hypertension. L-NAME decreased sO2 in L and JZ+D at GD14 and GD18 in association with fetal growth restriction and higher blood pressure. Hypoxia-inducible factor 1α immunostaining was higher in L-NAME vs. control mice at GD14. Fetal sO2 levels were similar between l-NAME and control mice at GD14 and GD18. In contrast to untreated C57Bl/6, L-NAME decreased placental sO2 at GD14 and GD18 vs. GD10 or GD12. Placental sO2 was lower in fetal growth restriction in an angiotensin-converting enzyme 2 knockout mouse model characterized by placental hypoxia. On phantom studies, patterns of sO2 measured directly correlated with those measured by PAI. In summary, PAI enables the detection of placental and fetal oxygenation during normal and pathologic pregnancies in mice.—Yamaleyeva, L. M., Sun, Y., Bledsoe, T., Hoke, A., Gurley, S. B., Brosnihan, K. B. Photoacoustic imaging for in vivo quantification of placental oxygenation in mice.

To determine whether there are changes in blood gas and acid-base status with advancing gestation in the fetal lamb, similar to that reported in the human fetus, blood gas, acid-base, and blood metabolite values were measured in 447 control, arterial blood samples from 108 chronically instrumented fetal lambs between 103 and 146 days gestation. With advancing gestation, Po2, pH, O2saturation, and O2content fell significantly, while Pco2and hemoglobin concentration increased. Blood glucose and lactate concentrations were unchanged, although the lactate level increased with decreasing Po2, particularly when below ∼13 mmHg. Multiple linear regression indicated that increasing fetal number was associated with decreased Po2and glucose level and increased pH, HCO3−, base excess, and lactate concentration. Hemoglobin concentration was higher in female than male lambs. Overall, there was a linear relationship between glucose concentration and birth weight. It is concluded that in fetal lambs as in the human fetus, there are changes in blood gas and acid-base status with advancing gestation. This may be due to the decrease in fetal weight-normalized uterine and umbilical blood flows than occurs in these and other species as gestation proceeds. In addition, the reduced birth weight in twin and triplet lambs may be due to hypoglycemia rather than hypoxemia.

The routine administration of supplemental oxygen to women undergoing elective caesarean section under regional anesthesia in order to optimize oxygen supply to the fetus is common anesthetic practice in many German hospitals. However, this practice has been controversially discussed in the non-German literature for many years. This review presents and discusses the pros and cons of routinely providing supplemental oxygen to a parturient during caesarean section on the basis of the literature published over the last 30 years. Proponents of routine oxygen administration point to potential and unforeseeable risks of caesarean sections and consider the prophylactic administration of oxygen based on physiological considerations to be advantageous in terms of patient safety. Interestingly, data regarding the effects of an increased maternal FIO2 on improvement of fetal oxygenation are inconsistent, therefore, no unambiguous recommendation concerning which FIO2 to choose can be given. Opponents of routine oxygen supplementation allude above all to an increase in free radical activity in both mother and fetus; however, data in this respect are not consistent either. As supplemental oxygen to patients undergoing elective caesarean section without any risk factors under regional anesthesia is associated with potential risks while no advantage has so far been demonstrated, routine administration of oxygen has to be challenged and is no longer considered to be indicated by many. On the contrary, in cases of emergency with a concomitant risk of hypoxia for mother and fetus, administration of oxygen is indispensable in the light of present data.

Fetal welfare during labor and delivery is commonly monitored through the cardiotocogram (CTG), the combined registration of uterus contractions and fetal heart rate (FHR). The CTG gives an indication of the main determinant of the acute fetal condition, namely its oxygen state. However, interpretation is complicated by the complex relationship between the two. Mathematical models can be used to assist with the interpretation of the CTG, since they enable quantitative modeling of the cascade of events through which uterine contractions affect fetal oxygenation and FHR. We developed a mathematical model to simulate ‘early decelerations’, i.e. variations in FHR originating from caput compression during uterine contractions, as mediated by cerebral flow reduction, cerebral hypoxia and a vagal nerve response to hypoxia. Simulation results show a realistic response, both for fetal and maternal hemodynamics at term, as for FHR variation during early decelerations. The model is intended to be used as a training tool for gynaecologists. Therefore 6 clinical experts were asked to rate 5 real and 5 model-generated CTG tracings on overall realism and realism of selected aspects. Results show no significant differences between real and computer-generated CTG tracings.

Accurate assessment of uterine activity during labor is essential to promote optimal patient outcomes. This review provides clinicians with information to develop an evidence-based, standardized approach to the evaluation and management of uterine activity during labor including identification and treatment of excessive uterine activity. Common terminology is defined in an effort to enhance clear and direct communication and accurate assessment. The latest evidence regarding normal labor is presented along with physiology related to uterine activity and fetal oxygenation. Suggestions for managing excessive uterine activity are offered as well as a synopsis of risk reduction strategies for clinical practice.

Pregnant women without medical or obstetric problems should be encouraged to exercise. The paucity of experimental data on exercise in pregnancy forces recommendations to be drawn from a synthesis of available information. Vigorous exercise during pregnancy seems to pose no adverse maternal or neonatal outcomes. Nonetheless, the safety of vigorous exercise necessitates surveillance of fetal growth, the woman's weight, nutritional intake, and exercise duration and intensity.

Objective To analyze the relation between fetal acid-base and neonatal status in an observational cohort study of 900 consecutive women with singleton pregnancies at term undergoing elective cesarean section. Methods The women were divided into 3 groups according to the type of anesthesia administered. Fetal acid-base status was assessed from umbilical cord blood (both artery and vein) and intermediate neonatal outcome was noted. Results Epidural anesthesia was associated with the highest pH. The lowest pH and the highest p C0 2 values were associated with spinal anesthesia. Although maternal general anesthesia was associated with the highest values for partial pressure and saturation of oxygen in umbilical arterial blood, the newborns were more likely to be depressed than those born following spinal ( P = 0.0016) or epidural ( P = 0.0002) anesthesia. Conclusions If fetal oxygenation is the goal, general anesthesia provides the highest values for partial pressure and saturation of oxygen in umbilical arterial blood. However, epidural anesthesia was associated with better fetal and neonatal status than either spinal or general anesthesia.

The gold standard for assessment of fetal well being in labor is the adequacy of fetal oxygenation using continuous electronic fetal monitoring. Additional biophysical properties of the fetus are increasingly being used to ascertain the health of the intrauterine environment. This article focuses on the detection and management of the compromised fetus. The article describes the history, physiologic basis, and current techniques for fetal monitoring. In addition, it presents the common diagnostic tools used to identify the compromised fetus and available options for the management of fetal intolerance of labor.

October is a special month for the International Federation of Obstetrics and Gynecology (FIGO) because it is the month of our World Congress. The Editorial Board and the editorial staff of the International Journal of Gynecology and Obstetrics (IJGO) warmly welcome our readers to Vancouver for the Congress. The IJGO continues to be one of the leading journals in women’s health because of your continued contribution to the journal through submission of manuscripts and provision of high-quality reviews of these manuscripts. In collaboration with the incoming FIGO President Prof C.N. Purandare, the IJGO has published the 2015World Report on Women’s Health, which will be available at the Congress and serves to highlight the aspects of women’s health where FIGO is concentrating its efforts. In the journal’s role as the official mouthpiece of FIGO, the October issue of the IJGO contains the FIGO Consensus Guidelines for Intrapartum Fetal Monitoring. These guidelines cover the theory and practice of intrapartum fetal monitoring. They address the physiology of fetal oxygenation and emphasize the goals of fetal monitoring, in addition to explaining how to use different technologies, ranging from intermittent auscultation to cardiotocography and other adjunctive technologies. The FIGO guidelines are useful for clinical practice