Antenatal fetal surveillance "Assessment of the AFV"

Assessment of Amniotic Fluid Volume in Pregnancy

Amniotic fluid (AF) is an integral part of the fetal environment and is essential for fetal growth and development. Pathways of AF recirculation include the fetal lungs, swallowing, absorption through the fetal gastrointestinal tract, excretion through fetal urine production, and movement. In addition to being a marker for fetal health, adequate AF is necessary for fetal lung development, growth, and movement. The role of diagnostic imaging is to provide a detailed fetal survey, placental evaluation, and clinical correlation with maternal conditions to help identify causes of AF abnormalities and thereby enable specific therapy. Oligohydramnios prompts evaluation for fetal growth restriction as well as genitourinary issues, including renal agenesis, multicystic dysplastic kidneys, ureteropelvic junction obstruction, and bladder outlet obstruction. Premature preterm rupture of membranes should also be clinically excluded as a cause of oligohydramnios. Clinical trials evaluating amnioinfusion are underway as a potential intervention for renal causes of oligohydramnios. Most cases of polyhydramnios are idiopathic, with maternal diabetes being a common cause. Polyhydramnios prompts evaluation for fetal gastrointestinal obstruction and oropharyngeal or thoracic masses, as well as neurologic or musculoskeletal anomalies. Amnioreduction is performed only for maternal indications such as symptomatic polyhydramnios causing maternal respiratory distress. Polyhydramnios with fetal growth restriction is paradoxical and can occur with maternal diabetes and hypertension. When these maternal conditions are absent, this raises concern for aneuploidy. The authors describe the pathways of AF production and circulation, US and MRI assessment of AF, disease-specific disruption of AF pathways, and an algorithmic approach to AF abnormalities. ^©RSNA, 2023 Online supplemental material is available for this article. Quiz questions for this article are available through the Online Learning Center.

Maternal and neonatal outcomes following induction of labor for fetal growth restriction: Extra-amniotic balloon versus prostaglandins

OBJECTIVE

To compare perinatal outcomes in pregnancies with fetal growth restriction (FGR) undergoing induction of labor by extra-amniotic balloon (EAB) versus prostaglandin E₂ (PGE₂ ).

METHODS

A retrospective cohort study of women with singleton pregnancies and FGR, undergoing induction at term via EAB, PGE₂ , or both, at a single medical center (2014-2017). Primary outcome was rate of cesarean deliveries (CDs). Secondary outcomes included composite maternal and neonatal outcomes.

RESULTS

Overall, 266 women met the inclusion criteria. Among them, 131 (49.2%) underwent induction by PGE₂ , 116 (43.6%) by EAB, and 19 (7.14%) by both methods. No differences were noted in baseline characteristics. Rate of CD (17.24% vs. 6.11% vs. 10.53%, P = 0.022) and maternal composite outcome (18.97% vs. 6.11% vs. 10.53%, P < 0.01) were higher among women who underwent induction by EAB compared with PGE₂ or both. No difference was noted between groups in neonatal outcomes. In a multivariable logistic regression, rates of cesarean delivery and composite maternal outcome were no longer higher in the EAB group (adjusted odds ratio [aOR] 1.68, 95% confidence interval [CI] 0.68-4.16, P = 0.260; and aOR 1.94, 95% CI 0.84-4.45, P = 0.120, respectively).

CONCLUSION

EAB and PGE₂ have comparable maternal and neonatal outcomes when used for induction of labor due to FGR.

Window to the Womb: Amniotic Fluid and Postnatal Outcomes

Amniotic fluid volumes are tightly regulated, and amniotic fluid derangement can indicate maternal complications or fetal abnormalities. Ultrasound estimate of amniotic fluid provides a tool to evaluate the maternal-fetal-placental interface in real-time. Oligohydramnios and polyhydramnios are associated with adverse maternal and neonatal outcomes. Oligohydramnios is associated with adverse maternal and neonatal outcomes including cesarean delivery, operative vaginal delivery, induction of labor, postpartum hemorrhage, small for gestational age neonate, intrauterine demise, neonatal death, NICU admission, and APGAR less than 7 at. 5 minutes of life Polyhydramnios is associated with adverse outcomes including cesarean delivery, induction of labor, placental abruption, shoulder dystocia, cord prolapse, postpartum hemorrhage, intrauterine fetal demise, NICU admission, neonatal death, APGAR less than 7 at 5 minutes of life, large for gestational age neonate, and respiratory distress syndrome. Therefore, Amniotic fluid should be evaluated when maternal or fetal well-being is in question.

"The First Thousand Days" Define a Fetal/Neonatal Neurology Program

Gene-environment interactions begin at conception to influence maternal/placental/fetal triads, neonates, and children with short- and long-term effects on brain development. Life-long developmental neuroplasticity more likely results during critical/sensitive periods of brain maturation over these first 1,000 days. A fetal/neonatal program (FNNP) applying this perspective better identifies trimester-specific mechanisms affecting the maternal/placental/fetal (MPF) triad, expressed as brain malformations and destructive lesions. Maladaptive MPF triad interactions impair progenitor neuronal/glial populations within transient embryonic/fetal brain structures by processes such as maternal immune activation. Destructive fetal brain lesions later in pregnancy result from ischemic placental syndromes associated with the great obstetrical syndromes. Trimester-specific MPF triad diseases may negatively impact labor and delivery outcomes. Neonatal neurocritical care addresses the symptomatic minority who express the great neonatal neurological syndromes: encephalopathy, seizures, stroke, and encephalopathy of prematurity. The asymptomatic majority present with neurologic disorders before 2 years of age without prior detection. The developmental principle of ontogenetic adaptation helps guide the diagnostic process during the first 1,000 days to identify more phenotypes using systems-biology analyses. This strategy will foster innovative interdisciplinary diagnostic/therapeutic pathways, educational curricula, and research agenda among multiple FNNP. Effective early-life diagnostic/therapeutic programs will help reduce neurologic disease burden across the lifespan and successive generations.

Effect of coffee consumption on fetal renal artery blood flow and amniotic fluid volume in third trimester of pregnancy

Objective:

Coffee is frequently (one or two cups/day) consumed throughout pregnancy. Although there are a few studies evaluating caffeine effects on pregnancy; however, a diuretic effect of caffeine on fetal kidneys has not been reported. Therefore, after drinking coffee whether changing of amniotic fluid index (AFI) and fetal renal artery blood flow (FRABF, RI, Resistive index; PI, Pulsatility index) were evaluated in this study.

Methods:

This clinical study was performed with two groups. For the study group, 63 participants with isolated borderline oligohydramnios who agreed to drink one cup of instant coffee were included in this study while 63 participants with isolated borderline oligohydramnios who did not drink one cup of instant coffee formed the control group. AFI, RI and PI were evaluated both before and after coffee intake.

Results:

Maternal characteristics of all study population were homogenous. FRABF indices were similar in both before and after coffee consumption. AFI was increased significantly six hours after drinking coffee (p<0.001).

Conclusions:

The coffee consumption increased the amniotic fluid volume. However it does not seem to affect on FRABF. According to our study findings, coffee consumption may offer a new opportunity to improve amniotic fluid volume for pregnant women with oligohydramnios.

Fetal Growth Restriction

Fetal growth restriction (FGR) is a failure of fetus to reach its expected biological growth, based on its genetically predetermined potential. Whenever effective fetal weight is less than, 10th percentile or 2 standard deviation of population-specific growth curve, it is considered small for gestational age (SGA). The FGR is associated with poor somatic growth with concomitant changes in placental and cerebral blood flow and/or biochemical markers along with EBW < 3rd percentile. It is an important cause of perinatal mortalities and morbidities. Ultrasound plays a definitive role in diagnosis and its management. This article is aimed to mini review the published guidelines on FGR and SGA and summarize the areas of consensus.

How Well Do the Popular Ultrasonic Techniques Estimate Amniotic Fluid Volume and Diagnose Oligohydramnios, in Fact?

The aims of the study were to compare the different estimation methods for the diagnosis of oligohydramnios and to determine concordance between estimated amniotic fluid volume (AFV) measured by ultrasonography and actual AFV measured directly. Another purpose was to investigate the effect of oligohydramnios on neonatal outcome. This study was done at a tertiary care center. The participants were scheduled between 37 and 40 weeks for cesarean delivery. Estimated AFV was ultrasonographically assessed, and then actual AFV was directly measured during the cesarean delivery to compare the subjective method (SM), amniotic fluid index (AFI), single deepest pocket (SDP), and 2-diameter pocket. Totally, 138 patients were included in the present study. Of 35 (34%), 24 (21%), 12 (9.5%), and 10 (7.8%) were defined as oligohydramnios by the SM, AFI, SDP, and 2-diameter pocket, respectively. The number of patients with actual oligohydramnios was 35 (34%). Most authors suggest as a method use of the SDP more than the AFI, because of overmanagement through the AFI. However, this study, which was conducted using both nonprejudiced and criterion-standard methods, showed that the SM and AFI technique were more successful to estimate oligohydramnios than other methods. Also, adverse pregnancy outcome was not closely associated with isolated oligohydramnios.

Fetal neurology: Principles and practice with a life-course perspective

Clinical service, educational, and research components of a fetal/neonatal neurology program are anchored by the disciplines of developmental origins of health and disease and life-course science as programmatic principles. Prenatal participation provides perspectives on maternal, fetal, and placental contributions to health or disease for fetal and subsequent neonatal neurology consultations. This program also provides an early-life diagnostic perspective for neurologic specialties concerned with brain health and disease throughout childhood and adulthood. Animal models and birth cohort studies have demonstrated how the science of epigenetics helps to understand gene-environment interactions to better predict brain health or disease. Fetal neurology consultations provide important diagnostic contributions during critical or sensitive periods of brain development when future neurotherapeutic interventions will maximize adaptive neuroplasticity. Age-specific normative neuroinformatics databases that employ computer-based strategies to integrate clinical/demographic, neuroimaging, neurophysiologic, and genetic datasets will more accurately identify either symptomatic patients or those at risk for brain disorders who would benefit from preventive, rescue, or reparative treatment choices throughout the life span.

Updating the amniotic fluid index nomograms according to perinatal outcome

Background: The two most commonly used nomograms for amniotic fluid index (AFI) were developed by Moore and Cayle and Magann et al. However, there are several inconsistencies between the two methods.Objective: The aim of the study was to determine whether these differences carry clinical significance.Methods: A retrospective cohort of women with singleton pregnancies evaluated for AFI during pregnancy at a tertiary medical center in 2007-2014 were divided into five groups: group A, definite oligohydramnios-AFI below the fifth percentile according to the nomograms of both Moore and Cayle and Magann et al.; group B, intermediate oligohydramnios-AFI below the fifth percentile according to only one nomogram (Moore and Cayle); group C, euhydramnios-normal AFI according to both nomograms; group D, intermediate polyhydramnios-AFI above the 95th percentile according to one nomogram (Magann et al.); group E, definite polyhydramnios-above the 95th percentile according to both nomograms. The association of group by maternal and perinatal outcomes was analyzed.Results: A total of 6987 women were included: group A, 996 (14%); group B, 1344 (19%); group C, 2561 (37%); group D, 1051 (15%); group E, 1034 (15%). Group B (intermediate oligohydramnios) was characterized by significantly lower rates of adverse perinatal outcomes than group A (definite oligohydramnios): small for gestational age neonate (12.3 versus 15.2%, p = .05), neonatal intensive care unit admission (11.1 versus 21.5%; p < .001), composite respiratory outcome (4.8 versus 9.8%; p < .001), and neonatal sepsis (6.4 versus 10.8%; p < .001). No such differences were found between groups B and C. Group D (intermediate polyhydramnios) differed from group E (definite polyhydramnios) by lower rates of 5 minutes Apgar score <7 (1.3 versus 3.2%; p = .003), neonatal intensive care unit admission (10.9 versus 14.4%; p = .02), and major congenital anomalies (1.7 versus 5.6%; p = .02). There was no difference in these parameters between groups D and C.Conclusion: This study suggests that intermediate oligohydramnios and intermediate polyhydramnios are not associated with adverse perinatal outcomes. Outcome in these pregnancies is similar to pregnancies with euhydramnios. Commonly used AFI nomograms should be updated.