Placental Blood Flow Research Articles

Examination of placental three-dimensional power Doppler indices and perinatal outcome in pregnancies complicated by intrauterine growth restriction

Development of intrauterine growth restriction (IUGR) can be traced back to maternal or fetal factors, but in many cases we find placental factors (reduced placental circulation) in the background. Our aim was to examine whether the reduced placental bloodperfusion and vascularity show any correlation with cesarean section frequency and the clinical outcome in IUGR pregnancies. The aim of the present study was also to use a properly calibrated and reproducible method for evaluating placental blood flow, that can later be incorporated into the routine examination. 254 women were recruited in our prospective case-control study. The 3 dimensional power Doppler (3DPD) ultrasound indices; vascularisation index (VI), flow index (FI) and vascularization flow index (VFI) were measured on each participant. Median VI was 3.7% (interquartile range [IQR] 3.2%-4.2%) in the IUGR group and 10.1% (IQR 8.6%-10.9%) in the control group (p = 0.001). Median FI value was 40.0 (IQR 39.7-42.5) in the IUGR group and 45.1 (IQR 44.1-53.1) in the control group (p = 0.012). Median VFI was 2.2 (IQR 2.1-2.4) in the IUGR group and 4.8 (IQR 4.4-5.3) in the control. The 3DPD indices may be useful for examining changes in circulation in IUGR pregnancies to characterize the underlying pathology. Orv Hetil. 2017; 158(26): 1008-1013.

Vitamin C to Decrease the Effects of Smoking in Pregnancy on Infant Lung Function (VCSIP): Rationale, design, and methods of a randomized, controlled trial of vitamin C supplementation in pregnancy for the primary prevention of effects of in utero tobacco smoke exposure on infant lung function and respiratory health

Despite strong anti-smoking efforts, at least 12% of American women cannot quit smoking when pregnant resulting in >450,000 smoke-exposed infants born yearly. Smoking during pregnancy is the largest preventable cause of childhood respiratory illness including wheezing and asthma. Recent studies have shown a protective effect of vitamin C supplementation on the lung function of offspring exposed to in utero smoke in a non-human primate model and an initial human trial. Vitamin C to Decrease the Effects of Smoking in Pregnancy on Infant Lung Function (VCSIP) is a randomized, double-blind, placebo-controlled trial to evaluate pulmonary function at 3months of age in infants delivered to pregnant smokers randomized to 500mg/day of vitamin C versus placebo during pregnancy. Secondary aims evaluate the incidence of wheezing through 12months and pulmonary function testing at 12months of age. Women are randomized between 13 and 23weeks gestation from clinical sites in Portland, Oregon at Oregon Health & Science University and PeaceHealth Southwest Medical Center and in Indianapolis, Indiana at Indiana University and Wishard Hospital. Vitamin C supplementation occurs from randomization to delivery. Monthly contact with participants and monitoring of medical records is performed to document medication adherence, changes in smoking and medical history, and adverse events. Pulmonary function testing of offspring occurs at 3 and 12months of age and incidence of wheezing and respiratory illness through 12months is captured via at least quarterly questionnaires. Ancillary studies are investigating the impact of vitamin C on placental blood flow and DNA methylation.

Maternal Methyl-Cycle Amino Acid Profile and Kinetics: Relation with Placental Growth

Maternal intake of quality protein regulates placental development and function thereby affecting fetal growth. Considering the prevalence of inadequate intakes of quality protein in Indian pregnant women, understanding the interplay between maternal supply of protein, its metabolism and fetoplacental growth becomes important. A secondary analysis of data from an open labelled-randomized intervention trial with 500 ml milk/day on south Indian pregnant women with marginally low vitamin B12 status, was performed to assess the relations between placental parameters and maternal trimester 3 methyl-cycle amino acid status as well as kinetics. This analysis was performed for 42 pregnancies from the trial where placentae had been collected and placental parameters had been measured. For these pregnancies, data on trimester 3 methionine, serine and glycine kinetics as well as plasma free amino acid concentrations were available. Protein intake and plasma citrulline concentrations were positively correlated at trimester 3 (ρ = 0.34, P = 0.027). Placental weight correlated positively with methyl-cycle specific amino acid concentrations [methionine (ρ = 0.32, P = 0.0388), serine (ρ = 0.49, P = 0.0009)], methionine kinetics [total methionine flux rates (ρ = 0.42, P = 0.006), RM (ρ = 0.45, P = 0.003), TS (ρ = 0.32, P = 0.046), TM (ρ = 0.45, P = 0.004)] and with birth weight (ρ = 0.57, P < 0.001). Findings from the current study indicate that maternal amino acid availability and more importantly, maternal methionine kinetics, positively influenced placental growth, likely mediated by key amino acids such as citrulline, which is known to regulate placental blood flow and function. As an appropriately functioning placenta is indispensable for fetal growth, these findings will form the basis for detailed mechanistic explorations into the placental regulation of maternal supply of amino acid to the fetus for designing effective intervention strategies towards optimizing fetomaternal health during and after pregnancy.

Можливості використання L-аргініну в акушерстві та гінекології для лікування патологій, спричинених ендотеліальною дисфункцією

The objective: to investigate the clinical efficacy of the drug Tivomax (arginine hydrochloride 42 mg/ml) at a dose of 100 ml intravenously 1 time a day course 10 days for medical correction of placental dysfunction. Patients and methods. Under our supervision there were 30 pregnant women at term 32-34 weeks with circulatory disorders in the system mother-placenta-fetus. To assess the functional state of the fetoplacental complex used sonometric methods, Doppler Velocimetry of blood flow in the placental system and the definition of biophysical profile of the fetus. Results. The study of peculiarities of haemodynamics in the mother-placenta-fetus was discovered isolated changes in blood flow of uterine arteries in 14 (46.7%) women, accompanied by: a decrease in the diastolic component in the end-diastolic velocity krovotoka – 42.3±2.14 cm/s, increased resistance index – 0.65±0.08 and systolo-diastolic ratio was 2.47±0.32. Violation of placental blood flow was observed in 11 (36.7%) patients. All the patients for the correction of violations was given the drug Tivomax. Conclusion. Tivomax as a donor L-arginine has pronounced effect on the vascular tone as the uterine arteries, and arteries of the umbilical cord, contributing to the normalization of hemodynamics in the mother-placenta-fetus. Key words: Tivomax, L-arginine, endothelium. Obstetrics and gynecology, placental deficiency, preeclampsia

Evaluation of Placental Blood Flow in Patients with Placental Insufficiency

Evaluation of Placental Blood Flow in Patients with Placental Insufficiency

First trimester alcohol exposure alters placental perfusion and fetal oxygen availability affecting fetal growth and development in a non-human primate model

Prenatal alcohol exposure leads to impaired fetal growth, brain development, and stillbirth. Placental impairment likely contributes to these adverse outcomes, but the mechanisms and specific vasoactive effects of alcohol that links altered placental function to impaired fetal development remain areas of active research. Recently, we developed magnetic resonance imaging techniques in nonhuman primates to characterize placental blood oxygenation through measurements of T2* and perfusion using dynamic contrast-enhanced magnetic resonance imaging. The objective of this study was to evaluate the effects of first-trimester alcohol exposure on macaque placental function and to characterize fetal brain development invivo. Timed-pregnant Rhesus macaques (n=12) were divided into 2 groups: control (n=6) and ethanol exposed (n=6). Animals were trained to self-administer orally either 1.5 g/kg/d of a 4% ethanol solution (equivalent to 6 drinks/d) or an isocaloric control fluid from preconception until gestational day 60 (term is G168). All animals underwent Doppler ultrasound scanning followed by magnetic resonance imaging that consisted of T2* and dynamic contrast-enhanced measurements. Doppler ultrasound scanning was used to measure uterine artery and umbilical vein velocimetry and diameter to calculate uterine artery volume blood flow and placental volume blood flow. After noninvasive imaging, animals underwent cesarean delivery for placenta collection and fetal necropsy at gestational day 110 (n=6) or 135 (n=6). Fetal weight and biparietal diameter were significantly smaller in ethanol-exposed animals compared with control animals at gestational day 110. By Doppler ultrasound scanning, placental volume blood flow was significantly lower (P=.04) at gestational day 110 in ethanol-exposed vs control animals. A significant reduction in placental blood flow was evident by dynamic contrast-enhanced magnetic resonance imaging. As we demonstrated recently, T2* values vary throughout the placenta and reveal gradients in blood deoxyhemoglobin concentration that range from highly oxygenated blood (long T2*) proximal to spiral arteries to highly deoxygenated blood (short T2*). Distributions ofT2*throughout the placenta show significant global reduction in T2* (andhence high blood deoxyhemoglobin concentration) in ethanol-exposed vs control animals at gestational day 110 (P=.02). Fetal brain measurements indicated impaired growth and development at gestational day 110, but less so at gestational day 135 in ethanol-exposed vs control animals. Chronic first-trimester ethanol exposure significantly reduces placental perfusion and oxygen supply to the fetal vasculature later in pregnancy. These perturbations of placental function are associated with fetal growth impairments. However, differences between ethanol-exposed and control animals in placental function and fetal developmental outcomes were smaller at gestational day 135 than at gestational day 110. These findings are consistent with placental adaptation to early perturbations that allow for compensated placental function and maintenance of fetal growth.

Влияние бета-блокаторов на плацентарный и плодовый кровоток у беременных группы высокого риска

Влияние бета-блокаторов на плацентарный и плодовый кровоток у беременных группы высокого риска

Of mice and women: Statins as a potential treatment to prevent preeclampsia in antiphospholipid syndrome.

Pregnancy complications in antiphospholipid syndrome APS have been associated with placental insufficiency. While in vitro and ex vivo studies suggest that the placenta is the main target organ in obstetric APS, in vivo data was missing. Using 111In labelled antiphospholipid antibodies (aPL) and single photon emission computed tomography we identified the placenta as the main organ target in a new mouse model of obstetric APS that closely resembles the clinical scenario. The cause of placental insufficiency in APS was attributed to the procoagulant effects of aPL antibodies. However, we demonstrated that APS is a proinflammatory syndrome. Based on our previous findings on the crucial role of complement activation in placental mal perfusion in APS, we developed an MRI-based method in which anti-complement C3-targeted ultrasmall superparamagnetic iron oxide (USPIO) nanoparticles were used for the noninvasive detection of complement activation in placenta in utero. C3 deposition was detected in the placenta using this novel method, confirming the role of inflammation in obstetric APS. Management of obstetric APS is based on attenuating the procoagulant state. In many cases, however, there is no evidence of decidual thrombosis and instead inflammatory signs are present. Current treatment fails in a significant number of pregnancies- raising the need to explore other therapies to improve obstetrical outcome. Based on our preclinical studies in which pravastatin prevented adverse pregnancy outcomes in mouse models of preeclampsia and APS we performed translational studies in women. Our aim was to investigate the clinical use of pravastatin in APS women refractory to classical treatment LDA+LMWH that developed PE and/or severe IUGR. Eleven pregnant women with APS that developed PE or severe IUGR despite conventional antithrombotic therapy were treated with pravastatin (20mg/day) when signs of placental insufficiency (PE, IUGR) were observed. After pravastatin addition, placental blood flow and maternal symptoms of PE improved significantly leading to live birth in 100% of the patients. The beneficial effects of pravastatin were observed as early as 10 days, with a mean response time of 14.08 ± 3.25. Pregnancies survived 14 weeks [IQR 12–15] in patients cotreated with pravastatin. In this group. all babies were born close to term and alive and are now healthy while the neonates in the group that did not receive pravastatin experienced still births, preterm birth, were admitted at NICU and some of tem showed developmental abnormalities. Our study indicates that the addition of pravastatin at the time of onset of PE or severe IUGR to conventional treatment is worthy of further assessment in the management of women with APS and preeclampsia. RCT should be organized to confirm these observations.

Cell- and Tissue-Based Models for Study of Placental Development.

Decades of research into the molecular mechanisms by which the placenta forms and functions have sought to improve prevention, diagnosis, and management of disorders of this vital tissue. This research has included development of experimental models intended to replicate behavior of the native placenta in both health and disease. Animal models devised in rodents, sheep, cattle, or other domestic animal species have the advantage of being biologically "complete," but all differ to some degree in developmental timing and anatomical details compared to the human, suggesting subtle differences in molecular mechanism. Consequently, investigators have resorted to simplified systems, characterizing the mechanisms of placental development by using explants of maternal and fetal tissue, primary cell cultures, and immortalized or choriocarcinoma-derived cell lines. Such studies have advanced our understanding of mechanisms by which trophoblasts and associated tissues invade the endometrium, produce chorionic gonadotropin, manage immune tolerance of the fetus, or elaborate proteins that may contribute to placental dysfunction. More recently, use of three-dimensional spheroid cultures, computational modeling of placental tissue dynamics and blood flow, and bioengineering of tissue constructs have been undertaken, aimed to recapitulate the types of interactions that occur among diverse uterine and placental cell types in utero. New technologies and biological paradigms, stemming in part from the ongoing Human Placenta Project, promise to expand the array of available tools, increasing the likelihood that the years ahead will see significant improvements in the ability to prevent, diagnose, and treat life-threatening disorders of placental formation and function.

Angiogenesis Factors and Uterine Artery Doppler Ultrasound Resistance Index and Pulsatility Index in Pregnancies with High-Risk of Preeclampsia

Background: Endothelial dysfunction in the maternal circulation is an early finding during preeclampsia. Early diagnosis is very important to protect from maternal and neonatal morbidity we aimed to investigate the Vascular Endothelial Growth Factor (VEGF), anti-angiogenic VEGFR-1 (sVEGFR-1) or soluble FMS-like tyrosine kinase-1 (sFlt-1), and angiogenic PlGF using uterine artery Doppler ultrasonography and to evaluate placental vascular and fetomaternal blood flow changes.Methods: This cross-sectional study included a total of 64 pregnant women aged between 15 and 40 years who were in their 20 to 24 weeks of gestation and who were at a risk of developing preeclampsia. The patients were reexamined after delivery and divided into two groups according to those who developed preeclampsia/IUGR (n=9/7) and those who did not (n=48). We compared the VEGF, sFlt1 and PlGF using uterine artery Doppler ultrasonography changes.Results: Univariate analysis results of potential factors for preeclampsia were insignificant except age (p=0.047) and body mass index (0.004). In our ROC curve, the pvalue was found to be significant.Conclusion: Our study results demonstrated that biochemical and radiologic markers did not give any clues for early diagnosis at the 20 to 24 weeks of gestation.

Relationship between asymmetric dimethylarginine in umbilical cord plasma and birth weight follows a U-shaped curve.

Asymmetric dimethylarginine (ADMA) is a nonselective nitric oxide (NO) synthase inhibitor associated with cardiovascular and metabolic disorders. NO regulates placental blood flow, which plays an important role in fetal growth. Many epidemiological studies have disclosed that restricted fetal growth is associated with an increased risk of insulin resistance in adult life. We studied the relationship between ADMA in cord blood and birth size. Nine small for gestational age (SGA) and 32 appropriate for gestational age (AGA) infants were studied. Their cord plasma ADMA, insulin, insulin-like growth factor-1 (IGF-1), and adipocytokine levels were determined using enzyme-linked immunosorbent assays. The relationship between birth weight and ADMA levels followed a U-shaped curve rather than inverse linear associations expected over a full range of birth weight distribution. ADMA positively correlated with birth weight in the AGA group (p<0.001, R=0.590), and inversely correlated with birth weight in the SGA group (p<0.05, R=-0.741). ADMA inversely correlated with adiponectin (p<0.05, R=-0.289) and quantitative insulin sensitivity check index (QUICKI) (p<0.05, R=-0.294) in all subjects, and did not correlate with nitrogen oxides (NOX). Insulin, IGF-1, leptin, adiponectin and QUICKI were lower in the SGA than the AGA group. Plasma ADMA levels in cord blood may be a marker of fetal growth and insulin resistance.

Correlation of Oxidative Stress Markers with Ultrasound and Cardiotocography Parameters with Hypertension Induced Pregnancy.

Introduction:Pregnancy induced hypertension (PIH), especially preeclampsia, is a state of extremely increased oxidative stress (OS), due to decrease of antioxidant capacity in comparison to normotensive pregnant women. The consequences of increased state of oxidative stress with hypertension disorder in pregnancy are disorder of placental blood flow, intrauterine hypoxia of the fetus and disturbance in transfer of O2 manifested as pathological ultrasound (US) parameters (amount of amniotic fluid and biophysical profile of fetus) and cardiotocography parameters (CTG).Aim:The aim of this research is to analyze correlation of TBARS oxidative stress markers with ultrasound parameters of pregnancy course and cardiotocography parameters in pregnant women with PIH.Patients and methods:Research has been performed at the Clinic of Gynecology and Obstetrics, University Clinical Centre of the Republic of Srpska. It covered 200 pregnant women, 100 of them with PIH and 100 healthy pregnant women, at gestational age from 28 to 40 weeks. All pregnant women were analyzed for US parameters of pregnancy course and CTG records as well as oxidative stress biomarker, values of Thiobarbituric Acid (TBARS).Results:Pregnant women with PIH had high statistical significant (pre)pathological CTG records and US- biophysical profile, less amount of amniotic fluid and delivered in lower gestation compared to healthy pregnant women. TBARS high values are statistical high significant frequent with pregnant women with PIH, who had pathological and pre-pathological biophysical profile and CTG records, as well as with US less amount of amniotic fluid (p<0.01). The highest TBARS values were presented with PIH pregnant women and US of less amount of amniotic fluid 42.3 µmol.Conclusion:There is statistical strong connection between TBARS values, being used as oxidative stress markers, and diagnostic methods used in PIH diagnostics, ultrasound (amount of amniotic fluid, fetus biophysical profile) and cardiotocography recording. TBARS could also be significant in clinical application for assessment of pregnant women with PIH in order to make decisions on pregnancy termination period.

Changes in cardiac index during labour analgesia: A double-blind randomised controlled trial of epidural versus combined spinal epidural analgesia - A preliminary study.

Background and Aims:Combined spinal-epidural (CSE) analgesia for labour and delivery is occasionally associated with foetal bradycardia. Decreases in cardiac index (CI) and/or uterine hypertonia are implicated as possible aetiological factors. No study has evaluated CI changes following combined spinal analgesia for labour and delivery. This prospective, double-blind, randomised controlled trial evaluates haemodynamic trends during CSE and epidural analgesia for labour.Methods:Twenty-six parturients at term requesting labour analgesia were randomised to receive either epidural (E) or CSE analgesia. The Electrical Cardiometry Monitor ICON® was used to continuously determine maternal CI non-invasively, heart rate (HR) and stroke volume at baseline and up to 60 min after initiation of either intrathecal or epidural analgesia. In addition, maternal systolic blood pressure (SBP) and diastolic blood pressure (DBP) were recorded.Results:Both SBP and DBP had a similar, significant decrease following initiation of either epidural or CSE analgesia. However, parturients in the CSE group (n = 10) demonstrated a significant decrease in HR and CI compared to the baseline measurements. On the other hand, the parturients in the E (n = 13) group showed no decreases in either maternal HR or CI. Foetal heart changes were observed in four patients following CSE and one patient following an epidural.Conclusion:Labour analgesia with CSE is associated with a significant decrease in HR and CI when compared to labour analgesia with epidural analgesia. Further studies are necessary to determine whether a decrease in CI diminishes placental blood flow.

25: Effect of sildenafil citrate on fetal central hemodynamics and placental volume blood flow during hypoxemia in a chronic sheep model

25: Effect of sildenafil citrate on fetal central hemodynamics and placental volume blood flow during hypoxemia in a chronic sheep model

366: Pulling the plug on first trimester placental blood flow controversy; new insights from contrast-enhanced ultrasound

366: Pulling the plug on first trimester placental blood flow controversy; new insights from contrast-enhanced ultrasound

Effect of maternal exercises on biophysical fetal and maternal parameters: a transversal study.

ABSTRACTObjective To evaluate the acute effects of maternal and fetal hemodynamic responses in pregnant women submitted to fetal Doppler and an aerobic physical exercise test according to the degree of effort during the activity and the impact on the well-being.Methods Transversal study with low risk pregnant women, obtained by convenience sample with gestational age between 26 to 34 weeks. The participants carry out a progressive exercise test.Results After the exercise session, reduced resistance (p=0.02) and pulsatility indices (p=0.01) were identified in the umbilical artery; however, other Doppler parameters analyzed, in addition to cardiotocography and fetal biophysical profile did not achieve significant change. Maternal parameters obtained linear growth with activity, but it was not possible to establish a standard with the Borg scale, and oxygen saturation remained stable.Conclusion A short submaximal exercise had little effect on placental blood flow after exercise in pregnancies without complications, corroborating that healthy fetus maintains homeostasis even in situations that alter maternal hemodynamics.

Effects of maternal obesity on placental function and fetal development.

Obesity has reached epidemic proportions, and pregnancies in obese mothers have increased risk for complications including gestational diabetes, hypertensive disorders, pre-term birth and caesarian section. Children born to obese mothers are at increased risk of obesity and metabolic disease and are susceptible to develop neuropsychiatric and cognitive disorders. Changes in placental function not only play a critical role in the development of pregnancy complications but may also be involved in linking maternal obesity to long-term health risks in the infant. Maternal adipokines, i.e., interleukin 6 (IL-6), tumor necrosis factor alpha (TNF-α), leptin and adiponectin link maternal nutritional status and adipose tissue metabolism to placental function. Adipokines and metabolic hormones have direct impact on placental function by modulating placental nutrient transport. Nutrient delivery to the fetus is regulated by a complex interaction including insulin signaling, cytokine profile and insulin responsiveness, which is modulated by adiponectin and IL-1β. In addition, obese pregnant women are at risk for hypertension and preeclampsia with reduced placental vascularity and blood flow, which would restrict placental nutrient delivery to the developing fetus. These sometimes opposing signals regulating placental function may contribute to the diversity of short and long-term outcomes observed in pregnant obese women. This review focuses on the changes in adipokines and obesity-related metabolic hormones, how these factors influence placental function and fetal development to contribute to long-term metabolic and behavioral consequences of children born to obese mothers.

Non-invasive evaluation of placental blood flow: lessons from animal models.

In human obstetrics, placental vascularisation impairment is frequent as well as linked to severe pathological events (preeclampsia and intrauterine growth restriction), and there is a need for reliable methods allowing non-invasive evaluation of placental blood flow. Uteroplacental vascularisation is complex, and animal models are essential for the technical development and safety assessment of these imaging tools for human clinical use; however, these techniques can also be applied in the veterinary context. This paper reviews how ultrasound-based imaging methods such as 2D and 3D Doppler can provide valuable insight for the exploration of placental blood flow both in humans and animals and how new approaches such as the use of ultrasound contrast agents or ultrafast Doppler may allow to discriminate between maternal (non-pulsatile) and foetal (pulsatile) blood flow in the placenta. Finally, functional magnetic resonance imaging could also be used to evaluate placental blood flow, as indicated by studies in animal models, but its safety in human pregnancy still requires to be confirmed.

Exploring sexual dimorphism in placental circulation at 22–24 weeks of gestation: A cross-sectional observational study

IntroductionPlacental blood flow is closely associated with fetal growth and wellbeing. Recent studies suggest that there are differences in blood flow between male and female fetuses. We hypothesized that sexual dimorphism exists in fetal and placental blood flow at 22–24 weeks of gestation. MethodsThis was a prospective cross-sectional study of 520 healthy pregnant women. Blood flow velocities of the middle cerebral artery (MCA), umbilical artery (UA), umbilical vein (UV) and the uterine arteries (UtA) were measured using Doppler ultrasonography. UV and UtA diameters were measured using two-dimensional ultrasonography and power Doppler angiography. Volume blood flows (Q) of the UV and UtA were calculated. Maternal haemodynamics was assessed with impedance cardiography. UtA resistance (Ruta) was computed as MAP/Quta. ResultsUA PI was significantly (p = 0.008) higher in female fetuses (1.19 ± 0.15) compared with male fetuses (1.15 ± 0.14). MCA PI, cerebro-placental ratio (MCA PI/UA PI), Quv, UtA PI, Quta and Ruta were not significantly different between groups. At delivery, the mean birth weight and placental weight of female infants (3504 g and 610 g) were significantly (p = 0.0005 and p = 0.039) lower than that of the male infants (3642 g and 634 g). DiscussionWe have demonstrated sexual dimorphism in UA PI, a surrogate for placental vascular resistance, at 22–24 weeks of gestation. Therefore, it would be useful to know when this difference emerges and whether it translates into blood flow differences that may impact upon the fetal growth trajectory.

Abstract 131: Quantification of in vivo Placental Oxygenation Using Ultrasound-guided Spectral Photoacoustic Imaging

Preeclampsia, linked to abnormal placental development and ischemia, is a major cause of fetal and maternal death. Currently, the only cure is high-risk preterm delivery. Although clinical therapies to regulate the symptoms of preeclampsia—mean arterial pressure and proteinuria—it is unknown whether these therapeutics restore placental blood flow and reduce ischemia. We are developing ultrasound-guided spectral photoacoustic imaging to quantify placental ischemia and characterize therapeutic response. Ultrasound imaging is the preferred imaging modality to monitor pregnancy due to its safety, low cost, and mobility. Similar to ultrasound, photoacoustic imaging can provide co-registered images of tissue function. In these studies, pregnant SWV mice were imaged longitudinally from E12.5 to 18.5 using a Vevo LAZR small animal imaging system. Algorithms were developed to correlate the spectral photoacoustic data to a hemoglobin oxygenation (%sO 2 ) calibration standard—a phantom containing blood at varying partial pressures of oxygen. The phantom calibration standard deviation was 7.9% (n=3). The resulting ultrasound images were used to segment the placenta (Figure 1). An overlay of the %sO 2 on the ultrasound image maps placental variation in %sO 2 during longitudinal development. We demonstrate that our imaging method is capable of quantifying %sO2 and monitoring placental function in vivo . Future work will use our preclinical %sO2 quantification methods to characterize placental function during treatment for preeclampsia.