Primary prevention with vaginal chlorhexidine before 16 weeks reduces the incidence of preterm birth: results of the Preterm Labor Prevention Using Vaginal Antiseptics study.

BACKGROUND: Preterm labor is one of the leading causes of perinatal death and is currently considered a syndrome with many causes. One of the most important causes of preterm birth is ascending infection from bacterial vaginosis. Chlorhexidine has proven to be effective against bacterial vaginosis and against bacterial biofilms without affecting gestation. OBJECTIVE: We aimed to evaluate the effectiveness of a universal primary prevention strategy for preterm birth using intravaginal chlorhexidine applied before 16 weeks (Preterm Labor Prevention Using Vaginal Antiseptics study). STUDY DESIGN: We performed a prospective observational study with 2 cohorts of pregnant women that were assigned either to prevention of preterm birth by means of intravaginal chlorhexidine (Cum Laude Chlorhexidine, chlorhexidine digluconate 0.2%) before 16 weeks (n=413), or to no treatment following the usual hospital protocol (n=704). Primary outcomes were the incidence of spontaneous preterm birth before 34 and 37 weeks; the incidence of preterm birth before 34 and 37 weeks, including inductions for premature rupture of membranes; and the incidence of preterm birth before 34 and 37 weeks, including any indication for termination of pregnancy. Both cohorts were compared using Mann-Whitney and Fisher tests. Finally, a multivariable analysis, including the odds ratio was performed, adjusting for clinical parameters, to evaluate the importance of the different determinants in the prediction of preterm birth. RESULTS: In pregnancies treated with chlorhexidine, the incidences of spontaneous preterm birth; preterm birth, including induction for premature rupture of membranas; and preterm birth, including any indication for termination of pregnancy were at 34 and 37 weeks: 0% and 0%, 0.24% and 1.69, and 2.90% and 3.15%, respectively; whereas in nontreated pregnancies, these incidences were 9% and 11%, 12% and 23%, and 35% and 43%, respectively. According to the multivariable analysis, the incidence of preterm birth among women treated with chlorhexidine before 16 weeks was halved (Odds ratio, 0.52; P<.05). CONCLUSION: Universal treatment with vaginal chlorhexidine before 16 weeks reduces the incidence of preterm birth, especially before 34 weeks.

Does emigration by itself improve birth weight? Study in European newborns of Indo-Pakistan origin.

Objective: Our aim was to evaluate the effect of emigration on fetal birth weight (BW) in a group of pregnant women coming from the Indian subcontinent. Methods: This was a retrospective study in a mixed population of pregnant women from the Indian subcontinent that either moved to Europe or stayed in their original countries. The influence of emigration along with several pregnancy characteristics: GA at delivery, fetal gender, maternal age, height, weight, body mass index (BMI) and parity on BW was evaluated by means of multivariable linear regression analysis. Results: According to European standards, babies born to Indo-Pakistan emigrants and babies born to women staying in the Indian subcontinent were similarly small (BW centile 30± 29 and 30.1 ± 28, p<0.68). Multivariable regression demonstrated that emigration by itself did not exert a direct influence on BW (p  = 0.27), being BMI and gestational age at delivery the true determinants of BW (p<0.0001). Conclusions: Maternal BMI is the most relevant parameter affecting fetal growth regardless of the place of residence.

Cerebroplacental Ratio Prediction of Intrapartum Fetal Compromise according to the Interval to Delivery.

INTRODUCTION: A controversy exists about the accuracy of the cerebroplacental ratio (CPR) for the prediction of cesarean section for intrapartum fetal compromise (CS-IFC). Our aim was to evaluate whether the interval to delivery modifies the accuracy of CPR either as a single marker or combined with estimated fetal weight centile (EFWc), type of labor onset (TLO), and other clinical variables. METHODS: This was a multicenter retrospective study of 5,193 women with singleton pregnancies who underwent an ultrasound scan at 35+0-41+0 weeks and gave birth within 1 month of examination, at any of the participating hospitals in Spain, UK, and Italy. CS-IFC was diagnosed in case of an abnormal intrapartum fetal heart rate or intrapartum fetal scalp pH <7.20, requiring urgent cesarean section. The diagnostic ability of CPR in multiples of the median (CPR MoM) was evaluated at different intervals to delivery, alone and combined with EFWc, TLO, and other pregnancy data such as maternal age, maternal body mass index, parity, and fetal sex, for the prediction of CS-IFC by means of ROC curves and logistic regression analysis. RESULTS: The predictive ability of CPR MoM for CS-IFC worsened with the interval to delivery. In general, the best prediction was obtained prior to labor and by adding information related to EFWc and TLO (AUC 0.71 [95% CI: 0.64-0.79], 0.73 [95% CI: 0.66-0.80], and 0.75 [95% CI: 0.69-0.81]; p < 0.0001). Addition of more clinical data did not improve prediction. In addition, results did not vary when only cases with spontaneous onset of labor were studied. CONCLUSION: CPR MoM prediction of CS-IFC at the end of pregnancy worsens with the interval to delivery. Accordingly, it should be done in the short term and considering EFWc and TLO.

MicroRNA-132 is overexpressed in fetuses with late-onset fetal growth restriction.

Background and Aims: To evaluate the expression of microRNA 132 (miR-132) in fetuses with normal growth and in fetuses with late-onset growth restriction (FGR). Methods: In a prospective cohort study, 48 fetuses (24 with late-onset FGR and 24 with normal growth) were scanned with Doppler ultrasound after 34 weeks to measure the umbilical artery and middle cerebral artery pulsatility indices and followed until birth. Subsequently, blood samples from the umbilical cord were collected to evaluate the expression of miR-132 by means of Real-time quantitative polymerase chain reaction, determining the existence of normality cut-offs and associations with birth weight (BW) centile, cerebroplacental ratio multiples of the median (CPR MoM), and intrapartum fetal compromise (IFC). Results: In comparison with normal fetuses, late-onset FGR fetuses showed upregulation of miR-132 (33.94 ± 45.04 vs. 2.88 ± 9.32 2-ddC t, p < 0.001). Using 5 as a cut-off we obtained a sensitivity of 50% and a specificity of 96% for the diagnosis of FGR, while for IFC these values were respectively 27% and 73%. Expression of miR-132 was associated with BW centile but not with CPR MoM. Finally, the best detection of IFC was achieved combining miR-132 expression and CPR MoM (AUC = 0.69, p < 0.05). Conclusion: Fetuses with late-onset FGR show upregulation of miR-132. Further studies are needed to investigate the role of miR-132 in the management of late-onset FGR.

Healthy mothers with normal cardiotocograms at term. Is maternal age a true determinant of perinatal outcome?

OBJECTIVE: to study the true determinants of adverse perinatal outcome (APO) in term healthy mothers with normal cardiotocograph (CTG), evaluating the real influence of maternal age. MATERIAL AND METHODS: In a retrospective study, we assessed a group of 529 term healthy mothers with normal CTGs that regardless of maternal age, evolved spontaneously up to 41 ± 2 weeks. The result of the conservative management was evaluated by means of univariable and multivariable logistic regression analysis, determining the association of maternal age and other clinical and ultrasonographical parameters with APO. RESULT: In contrast with low CPR MoM (OR = 0.155, p = .014), induction of labor (OR = 2.273, p = .023) and low parity (OR = 0.494, p = .026), maternal age and birth weight centile did not prove to be true determinants of perinatal outcome. The multivariable model for prediction of APO using clinical parameters presented a sensitivity of 35% and 27% for a false positive rate of 10% and 5%, AUC 0.736 (95% CI 0.655-0.818), p < .0001). CONCLUSIONS: in healthy old mothers with normal CTGs at term, APO is determined by low CPR, the existence of labor induction and low parity, while no real influence was observed for maternal age, fetal smallness, and interval examination-delivery. These results do not support the current consensus on induction at earlier weeks to prevent adverse outcomes in all cases of advanced maternal age, advocating for a more individualized, customized, and less interventional management based on fetal hemodynamics.

Predictors of adverse perinatal outcome up to 34 weeks, a multivariable analysis study.

The objective was to evaluate the best predictors of adverse perinatal outcome (APO) in foetuses examined up to 34 weeks and delivered by spontaneous or induced labour. This was a retrospective study of 129 pregnancies that underwent an ultrasound Doppler examination at 23-34 weeks and entered into labour within 30 days. Cerebroplacental ratio (CPR) and mean uterine artery pulsatility index (mUtA PI) were converted into multiples of the median (MoM) and estimated foetal weight (EFW) into centiles to adjust for gestational age (GA). Sonographic and clinical parameters were evaluated using logistic regression analysis.The multivariable model for the prediction of APO presented a notable accuracy: Detection rate (DR) was 39.5% for a false positive rate (FPR) of 5% and 56.8% for a FPR of 10%, AUC 0.82, p < .0001. Significant predictors were GA, EFW centile, and CPR MoM, but not mUtA PI MoM. Moreover, the type of labour onset did not exert any influence on APO. In conclusion, up to 34 weeks, prediction of APO after spontaneous or induced labour may be done measuring CPR and EFW.IMPACT STATEMENTWhat is already known on this subject? Earlier in pregnancy, foetal growth restriction is caused by placental disease causing progressive hemodynamic changes. These changes have been exhaustively described. Conversely, information about the best predictors of adverse outcome is scarce.What do the results of this study add? The findings of this study show that prior to 34 weeks and up to 1 month before labour, labour outcome might be predicted by gestational age, foetal cerebroplacental ratio (CPR) and estimated foetal weight (EFW).What are the implications of these findings for clinical practice and/or further research? If CPR behaves as a good marker of outcome not only at the end of pregnancy but also earlier in gestation, it might be interrogated along with EFW in foetuses attempting vaginal delivery to determine the risk of adverse outcome.

Congenital knee dislocation, case report and review of the literature.

Congenital dislocation of the knee (CDK) is characterized by hyperextension of the knee with forward displacement of the proximal tibia. It is associated with other joint dislocations and deformities and may occur isolated or as part of different systemic syndromes. Despite its characteristic postnatal morphology, prenatal descriptions are very scarce. We report a case of CDK diagnosed at 20 weeks, discuss its physiopathology, diagnosis and management and review the current literature.

Sirenomelia, case report and review of the literature.

We present a case of sirenomelia diagnosed in the first trimester of pregnancy. The ultrasound examination showed fused lower extremities and an anechoic structure in the lower abdomen that is clue in the early diagnosis. The postmortem study showed the existence of a single umbilical artery (vitelline artery), with an origin in the abdominal aorta. This finding not only explained the presence of a vascular steal with subsequent underdeveloped of pelvic organs, but also differentiated this condition from caudal regression syndrome.

Birth-weight differences at term are explained by placental dysfunction and not by maternal ethnicity. Study in newborns of first generation immigrants.

OBJECTIVE: The aim of the study was to investigate the influence of ethnicity and cerebroplacental ratio (CPR) on the birth weight (BW) of first generation Indo-Pakistan immigrants' newborns. METHODS: This was a retrospective study in a mixed population of 620 term Caucasian and Indo-Pakistan pregnancies, evaluated in two reference hospitals of Spain and Italy. All fetuses underwent a scan and Doppler examination within two weeks of delivery. The influence of fetal gender, ethnicity, GA at delivery, CPR, maternal age, height, weight and parity on BW was evaluated by multivariable regression analysis. RESULTS: Newborns of first generation Indo-Pakistan immigrants were smaller than local Caucasian newborns (mean BW mean= 3048 ± 435 g versus 3269 ± 437 g, p < .001). Multivariable regression analysis demonstrated that all studied parameters, but maternal age and ethnicity, were significantly associated with BW. The most important were GA at delivery (partial R2 = 0.175, p < .001), CPR (partial R2 = 0.032, p < .001), and fetal gender (partial R2 = 0,029, p < .001). CONCLUSIONS: The propensity to a lower BW, explained by placental dysfunction but not by maternal ethnicity is transmitted to newborns of first generation immigrants. Whatever are the factors implied they persist in the new residential setting.

Diagnostic performance of cerebroplacental and umbilicocerebral ratio in appropriate for gestational age and late growth restricted fetuses attempting vaginal delivery: a multicenter, retrospective study.

BACKGROUND: Cerebroplacental Doppler studies have been advocated to predict the risk of adverse perinatal outcome (APO) irrespective of fetal weight. OBJECTIVE: To report the diagnostic performance of cerebroplacental (CPR) and umbilicocerebral (UCR) ratios in predicting APO in appropriate for gestational age (AGA) fetuses and in those affected by late fetal growth restriction (FGR) attempting vaginal delivery. STUDY DESIGN: Multicenter, retrospective, nested case-control study between 1 January 2017 and January 2020 involving five referral centers in Italy and Spain. Singleton gestations with a scan between 36 and 40 weeks and within two weeks of attempting vaginal delivery were included. Fetal arterial Doppler and biometry were collected. The AGA group was defined as fetuses with an estimated fetal weight and abdominal circumference >10th and <90th percentile, while the late FGR group was defined by Delphi consensus criteria. The primary outcome was the prediction of a composite of perinatal adverse outcomes including either intrauterine death, Apgar score at 5 min <7, abnormal acid-base status (umbilical artery pH < 7.1 or base excess of more than -11) and neonatal intensive care unit (NICU) admission. Area under the curve (AUC) analysis was performed. RESULTS: 646 pregnancies (317 in the AGA group and 329 in the late FGR group) were included. APO were present in 12.6% AGA and 24.3% late FGR pregnancies, with an odds ratio of 2.22 (95% CI 1.46-3.37). The performance of CPR and UCR for predicting APO was poor in both AGA [AUC: 0.44 (0.39-0.51)] and late FGR fetuses [AUC: 0.56 (0.49-0.61)]. CONCLUSIONS: CPR and UCR on their own are poor prognostic predictors of APO irrespective of fetal weight.

Association of first trimester fetal heart rate and nuchal translucency with preterm birth.

OBJECTIVE: To evaluate whether first trimester fetal heart rate (FHR) and nuchal translucency (NT) associate with preterm birth (PTB). METHODS: This was a comparative case-control study of 518 normal pregnancies with no history of PTB, of which 272 delivered at term (TB) and 246 progressed to spontaneous PTB prior to 37, 34, 32, and 28 weeks. Fetal heart rate (FHR) and NT values at the first-trimester scan were compared by means of univariable (Mann-Whitney) and multivariable logistic regression analysis considering hourglass membranes (HM) as the most severe PTB subgroup. Finally, severity trends for both parameters were investigated using correlations with gestational age (GA) at delivery and Kruskal-Walls tests. RESULTS: Regardless of GA at delivery, pregnancies affected with PTB showed higher FHR and thicker NT at the first trimester scan. The association was confirmed by the multivariable analysis and the severity trends, which paired the highest FHR and NT values with the most severe cases of PTB (p < .001) (p < .0001). CONCLUSION: Fetuses with subsequent late, early and very early PTB show higher values of NT and FHR at the first-trimester scan.

MicroRNA-185-5p: a marker of brain-sparing in foetuses with late-onset growth restriction.

To compare the expression of microRNA-185-5p (miR-185-5p) in normal foetuses and in foetuses with late-onset growth restriction (FGR) and to determine the factors influencing this expression. In a prospective study, 40 foetuses (22 of them with late-onset FGR and 18 with normal growth) were scanned with Doppler ultrasound after week 35 and followed until birth. Subsequently, blood samples from umbilical cords were collected after delivery to evaluate the expression of miR-185-5p using real-time qPCR. Finally, multivariable regression analysis was applied to determine the clinical and ultrasonographic factors influencing miR-185-5p expression in both normal and late-onset FGR foetuses. In comparison with normal foetuses, late-onset FGR foetuses expressed upregulation of miR-185-5p (2.26 ± 1.30 versus 1.27 ± 1.03 2^-ddCt, P = 0.011). Multivariable regression analysis confirmed that cerebroplacental ratio (P < 0.05) was the only determinant of this overexpression. FGR foetuses overexpress miR-185-5p in relation to brain-sparing. Future studies will be needed to investigate the role of miR-185 in the management of late-onset FGR.

Which is the best ultrasound parameter for the prediction of adverse perinatal outcome within 1 day of delivery?

OBJECTIVE: To compare the accuracies of several sonographic parameters for the prediction of adverse perinatal outcome (APO) prior to delivery. METHODS: This was a prospective study of fetuses attending the day hospital unit of a tertiary referral hospital that were scanned at 34-41 weeks and gave birth within 24 h of examination. APO was defined as a composite of abnormal intrapartum fetal heart rate or intrapartum fetal scalp pH < 7.20 requiring urgent cesarean section, neonatal umbilical cord pH < 7.10, 5' Apgar score <7 and postpartum admission to neonatal or pediatric intensive care units. The accuracies of the middle cerebral, vertebral and umbilical arteries pulsatility index multiples of the median (MoM), the cerebroplacental and vertebroplacental ratios MoM and the EFW in centiles for the prediction of APO was evaluated by means of ROC curves and logistic regression analysis. RESULTS: A total of 2140 fetuses were prospectively scanned, however only 182 entered into spontaneous or induced labor and were delivered within 24 h of examination. In this group, MCA PI MoM was the best predictor of APO (AUC = 0.76, 95% CI 0.66-0.85, p < .0001) followed by the CPR MoM (AUC = 0.73, 95% CI 0.63-0.84, p < .0001) and the VPR MoM (AUC = 0.71, 95% CI 0.61-0.81, p < .001). Logistic regression analysis indicated that MCA PI MoM was the only independent determinant for the prediction of APO. CONCLUSION: In a high-risk population of third-trimester fetuses delivering within 24 h of examination, the outcome may be moderately anticipated just with the information provided by the cerebral flow.

Role of prenatal magnetic resonance imaging in fetuses with isolated severe ventriculomegaly at neurosonography: A multicenter study.

OBJECTIVE: The aim of this study was to report the rate of additional anomalies detected exclusively at prenatal magnetic resonance imaging (MRI) in fetuses with isolated severe ventriculomegaly undergoing neurosonography. METHOD: Multicenter, retrospective, cohort study involving 20 referral fetal medicine centers in Italy, United Kingdom, Spain and Denmark. Inclusion criteria were fetuses affected by isolated severe ventriculomegaly (≥15 mm), defined as ventriculomegaly with normal karyotype and no other additional central nervous system (CNS) and extra-CNS anomalies on ultrasound. In all cases, a multiplanar assessment of fetal brain as suggested by ISUOG guidelines on fetal neurosonography had been performed. The primary outcome was the rate of additional CNS anomalies detected exclusively at fetal MRI within two weeks from neurosonography. Subgroup analyses according to gestational age at MRI (

The Diagnostic Ability of the Cerebroplacental Ratio for the Prediction of Adverse Perinatal Outcome and Intrapartum Fetal Compromise within One Day of Delivery.

OBJECTIVES: The objectives of this study were to evaluate the diagnostic abilities of the cerebroplacental ratio (CPR) for the prediction of adverse perinatal outcome (APO) and cesarean section for intrapartum fetal compromise (CS-IFC) within 1 day of delivery. DESIGN: Retrospective observational case-control study. METHODS: This was a study of 254 high-risk fetuses attending the day hospital unit of a tertiary referral hospital that underwent an ultrasound examination at 32-41 weeks and gave birth within 1 day of examination. APO was defined as a composite of abnormal intrapartum fetal heart rate or intrapartum fetal scalp pH <7.20 requiring urgent cesarean section, neonatal umbilical cord pH <7.10, 5-min Apgar score <7, and postpartum admission to neonatal or pediatric intensive care units. CS-IFC was defined in case of abnormal intrapartum fetal heart rate or intrapartum fetal scalp pH <7.20 requiring urgent cesarean section. The diagnostic ability of CPR for the prediction of APO and CS-IFC was calculated alone and in combination with estimated fetal weight and gestational clinical parameters, including the type of labor onset, using ROC curves and logistic regression analysis. RESULTS: CPR in multiples of the median (MoM) was a moderate predictor of APO (area under the curve [AUC] = 0.77, p < 0.0001) and CS-IFC (AUC = 0.82, p < 0.0001). The predictive abilities of the multivariable model for APO (AUC = 0.81, p < 0.0001) and CS-IFC (AUC = 0.82, p < 0.0001) did not differ from those of CPR alone . LIMITATIONS: The small number of cases and the scarcity of information concerning labor induction. CONCLUSION: In high-risk pregnancies, CPR MoM is a moderate predictor of APO and CS-IFC when performed within 24 h of delivery.

Comparison between Cerebroplacental Ratio and Umbilicocerebral Ratio in Predicting Adverse Perinatal Outcome in Pregnancies Complicated by Late Fetal Growth Restriction: A Multicenter, Retrospective Study.

INTRODUCTION: The role of cerebroplacental ratio (CPR) or umbilicocerebral ratio (UCR) to predict adverse intrapartum and perinatal outcomes in pregnancies complicated by late fetal growth restriction (FGR) remains controversial. METHODS: This was a multicenter, retrospective cohort study involving 5 referral centers in Italy and Spain, including singleton pregnancies complicated by late FGR, as defined by Delphi consensus criteria, with a scan 1 week prior to delivery. The primary objective was to compare the diagnostic accuracy of the CPR and UCR for the prediction of a composite adverse outcome, defined as the presence of either an adverse intrapartum outcome (need for operative delivery/cesarean section for suspected fetal distress) or an adverse perinatal outcome (intrauterine death, Apgar score <7 at 5 min, arterial pH <7.1, base excess of >-11 mEq/mL, or neonatal intensive care unit admission). RESULTS: Median CPR absolute values (1.11 vs. 1.22, p = 0.018) and centiles (3 vs. 4, p = 0.028) were lower in pregnancies with a composite adverse outcome than in those without it. Median UCR absolute values (0.89 vs. 0.82, p = 0.018) and centiles (97 vs. 96, p = 0.028) were higher. However, the area under the curve, 95% confidence interval for predicting the composite adverse outcome showed a poor predictive value: 0.580 (0.512-0.646) for the raw absolute values of CPR and UCR, and 0.575 (0.507-0.642) for CPR and UCR centiles adjusted for gestational age. The use of dichotomized values (CPR <1, UCR >1 or CPR <5th centile, UCR >95th centile) did not improve the diagnostic accuracy. CONCLUSION: The CPR and UCR measured in the week prior delivery are of low predictive value to assess adverse intrapartum and perinatal outcomes in pregnancies with late FGR.

Overexpression of microRNAs miR-25-3p, miR-185-5p and miR-132-3p in Late Onset Fetal Growth Restriction, Validation of Results and Study of the Biochemical Pathways Involved.

In a prospective study, 48 fetuses were evaluated with Doppler ultrasound after 34 weeks and classified, according to the cerebroplacental ratio (CPR) and estimated fetal weight (EFW), into fetuses with normal growth and fetuses with late-onset fetal growth restriction (LO-FGR). Overexpression of miRNAs from neonatal cord blood belonging to LO-FGR fetuses, was validated by real-time PCR. In addition, functional characterization of overexpressed miRNAs was performed by analyzing overrepresented pathways, gene ontologies, and prioritization of synergistically working miRNAs. Three miRNAs: miR-25-3p, miR-185-5p and miR-132-3p, were significantly overexpressed in cord blood of LO-FGR fetuses. Pathway and gene ontology analysis revealed over-representation of certain molecular pathways associated with cardiac development and neuron death. In addition, prioritization of synergistically working miRNAs highlighted the importance of miR-185-5p and miR-25-3p in cholesterol efflux and starvation responses associated with LO-FGR phenotypes. Evaluation of miR-25-3p; miR-132-3p and miR-185-5p might serve as molecular biomarkers for the diagnosis and management of LO-FGR; improving the understanding of its influence on adult disease.

Mathematical simulation of Doppler changes in late-onset smallness; progression patterns of cerebral and umbilical anomalies define two types of late-onset fetal growth restriction.

OBJECTIVE: To evaluate the progression of Doppler abnormalities in fetuses with late-onset fetal smallness (SGA) that become growth restricted (FGR). METHODS: 524 Doppler examinations of the umbilical and cerebral arteries systems, belonging to 442 late-onset SGA fetuses after week 34, were studied, evaluating by means of the statistical difference with the respective abnormal centiles, the pattern of progression into abnormal Doppler values and the distribution and cumulative sum of Doppler anomalies according to the interval to delivery. RESULTS: Only one third (33.5%, N = 148) of late-onset SGA fetuses presented Doppler anomalies, suggesting that most were of constitutional origin. The most frequent progression pattern into abnormal Doppler (N = 127, 85.81%) was that in which only one system (umbilical or cerebral) became abnormal. Half of fetuses debuted with abnormal umbilical flow (52%, N = 77) and half with cerebral anomalies (47.97%, N = 71), which were more likely to appear later and at shorter intervals to delivery (p = .007). These progression patters defined two varieties of late-onset FGR (type I and II) with similar outcome but different birth weight centiles (BW centile = 2.51, SD 2.91 versus 3.97, SD 3.17, p < .01). CONCLUSION: Two thirds of late-onset fetal smallness occurs without hemodynamic changes. In half of the remaining cases an initial cerebral vasodilation defines a group of fetuses with similar outcome but higher BW centile.

MicroRNA-148b-3p and MicroRNA-25-3p Are Overexpressed in Fetuses with Late-Onset Fetal Growth Restriction.

OBJECTIVE: It was the aim of this study to describe a micro-RNA (miRNA) profile characteristic of late-onset fetal growth restriction (FGR) and to investigate the pathways involved in their biochemical action. METHODS: In this prospective study, 25 fetuses (16 normal and 9 with FGR [estimated fetal weight <10th centile plus cerebroplacental ratio <0.6765 multiples of the median]) were evaluated with Doppler ultrasound after 36 weeks. Afterwards, for every fetus, plasma from umbilical vein blood was collected at birth, miRNA was extracted, and full miRNA sequencing was performed. Subsequently, comparisons were done in order to obtain those miRNAs that were differentially expressed. RESULTS: The FGR fetuses expressed upregulation of two miRNAs: miR-25-3p and, especially, miR-148b-3p, a miRNA directly involved in Schwann cell migration, neuronal plasticity, and energy metabolism (p = 0.0072, p = 0.0013). CONCLUSIONS: FGR fetuses express a different miRNA profile, which includes overexpression of miR-25-3p and miR-148b-3p. This information might improve our understanding of the pathophysiological processes involved in late-onset FGR. Future validation and feasibility studies will be required to propose miRNAs as a valid tool in the diagnosis and management of FGR.