Defining early vs late fetal growth restriction by placental pathology

Maternal factors and perinatal outcomes associated with early-onset versus late-onset fetal growth restriction: a meta-analysis

BACKGROUND

Fetal growth restriction (FGR) is considered to be one of the most common causes of adverse perinatal outcomes. This study conducted a meta-analysis of the maternal factors and perinatal outcomes associated with early-onset FGR (EO-FGR) compared to late-onset FGR (LO-FGR).

METHODS

Studies describing the maternal factors and/or perinatal outcomes in singleton pregnant women with ultrasound and Doppler-confirmed FGR published between 2014 and 2024 in Scopus, Web of Science, MEDLINE, and PubMed databases were systematically searched with protocol registered in PROSPERO (CRD42024588608). Results were expressed as odds ratio and mean differences with 95% confidence intervals or hazard ratios.

RESULTS

3825 pregnant women complicated with 1300 EO-FGR and 2525 LO-FGR from 14 studies were included. Pregnancies with preeclampsia were at higher risk of EO-FGR (OR 4.25, 95% CI 2.47-7.32, I2 = 77%), whereas pregnancies with EO-FGR were at higher risk of being delivered by cesarean section (OR 5.83, 95% CI 2.76-12.32, I2 = 98%). Severe perinatal outcomes were significantly higher in the EO-FGR, including APGAR <7 at 5 min (OR 6.35, 95% CI 2.98-13.56, I2 = 78), neonatal resuscitation (OR 6.11, 95% CI 3.08-12.12, I2 = 0), NICU admission (OR 13.38, 95% CI 3.70-48.33, I2 = 94), anemia (OR 117.68, 95% CI 3.23-4289.12, I2 = 76), jaundice (OR 6.39, 95% CI 2.98-13.69, I2 = 0), NEC (OR 12.77, 95% CI 3.00-54.40, I2 = 0), PVL (OR 7.59, 95% CI 1.30-44.28, I2 = 0), IVH (OR 5.09, 95% CI 2.19-11.82, I2 = 49), RDS (OR 7.08, 95% CI 1.55-32.39, I2 = 92), sepsis (OR 10.92, 95% CI 2.57-46.34, I2 = 0), and perinatal death (OR 10.01, 95% CI 5.76-17.39, I2 = 34).

CONCLUSION

Preeclampsia is significantly contributed as the maternal factor associated with a higher risk of EO-FGR. The risk of having a cesarean birth and severe perinatal outcomes are significantly higher in the EO-FGR.

Placental Protein Citrullination Signatures Are Modified in Early- and Late-Onset Fetal Growth Restriction

Fetal growth restriction (FGR) is an obstetric condition most frequently caused by placental dysfunction. It is a major cause of perinatal morbidity with limited treatment options, so identifying the underpinning mechanisms is important. Peptidylarginine deiminases (PADs) are calcium-activated enzymes that mediate post-translational citrullination (deimination) of proteins, through conversion of arginine to citrulline. Protein citrullination leads to irreversible changes in protein structure and function and is implicated in many pathobiological processes. Whether placental protein citrullination occurs in FGR is poorly understood. We assessed protein citrullination and PAD isozyme abundance (PAD1, 2, 3, 4 and 6) in human placental samples from pregnancies complicated by early- and late-onset FGR, compared to appropriate-for-gestational-age (AGA) controls. Proteomic mass spectrometry demonstrated that the placental citrullinome profile changed in both early- and late-onset FGR, with 112 and 345 uniquely citrullinated proteins identified in early- and late-onset samples, respectively. Forty-four proteins were citrullinated only in control AGA placentas. The proteins that were uniquely citrullinated in FGR placentas were enriched for gene ontology (GO) terms related to neurological, developmental, immune and metabolic pathways. A greater number of GO and human phenotype pathways were functionally enriched for citrullinated proteins in late- compared with early-onset FGR. Correspondingly, late-onset but not early-onset FGR was associated with significantly increased placental abundance of PAD2 and citrullinated histone H3, determined by Western blotting. PAD3 was downregulated in early-onset FGR while abundance of PAD 1, 4 and 6 was less altered in FGR. Our findings show that placental protein citrullination is altered in FGR placentas, potentially contributing to the pathobiology of placental dysfunction.

Association Between Placental Pathology and Early-Onset Fetal Growth Restriction: A Systematic Review

Objective: Fetal growth restriction (FGR) is defined as the failure of the fetus to achieve its genetically determined growth potential. Our aim is to compare the placental lesions present in early-onset fetal growth restriction with that of late-onset FGR. Methods: We performed a systematic review according to the PRISMA guideline. Observational studies, only in singleton pregnancies, evaluating the association between fetal growth restriction and placental lesions in early- versus late-onset FGR were included. Results: We included six articles. All studies showed a higher rate of maternal vascular malperfusion (MVM) lesions in the early-onset FGR groups when compared to late-onset ones. Five articles reported that early-onset FGR is often associated with pre-eclampsia. Conclusion: This review shows that early-onset FGR cases are associated with specific placental histopathology, such as maternal vascular malperfusion lesions. Placental histopathological examination is important to better understand the pathophysiology of FGR.

Predictive and Diagnostic Value of the Angiogenic Proteins in Patients With Chronic Kidney Disease

BACKGROUND

Our objective was to investigate the predictive and diagnostic accuracy of the angiogenic proteins sFlt-1 (soluble fms-like tyrosine kinase-1) and PlGF (placental growth factor) for preterm preeclampsia and explore the relationship between renal function and these proteins.

METHODS

We completed a blinded, prospective, longitudinal, observational study of patients with chronic kidney disease followed at a tertiary center (2018-2023). Serum samples were obtained at 3 time points along gestation (planned sampling): 12-16, 18-22, and 28-32 weeks. In addition, samples were obtained whenever preeclampsia was suspected (indicated sampling). sFlt-1 and PlGF levels remained concealed until the study ended. The primary outcome was preterm preeclampsia. The planned and indicated samples were used to estimate the predictive and diagnostic accuracy of the angiogenic proteins, respectively.

RESULTS

Of the 97 participants, 21 (21.6%) experienced preterm preeclampsia. In asymptomatic patients with chronic kidney disease, the angiogenic proteins were predictive of preterm preeclampsia only when sampled in the third trimester, in which case the sFlt-1/PlGF ratio (false positive rate of 37% for a detection rate of 80%) was more predictive than either sFlt-1 or PlGF in isolation. In patients with suspected preeclampsia, the diagnostic accuracy of the sFlt-1/PlGF ratio (false positive rate of 26% for a detection rate of 80%) was higher than that of sFlt-1 and PlGF in isolation. Diminished renal function was associated with increased levels of PlGF.

CONCLUSIONS

sFlt-1 and PlGF can effectively predict and improve the diagnostic accuracy for preterm preeclampsia among patients with chronic kidney disease. The optimal sFlt-1/PlGF ratio cutoff to rule out preeclampsia may need to be lower in patients with impaired renal function.

The medullary serotonergic centres involved in cardiorespiratory control are disrupted by fetal growth restriction

Fetal growth restriction (FGR) is associated with cardiovascular and respiratory complications after birth and beyond. Despite research showing a range of neurological changes following FGR, little is known about how FGR affects the brainstem cardiorespiratory control centres. The primary neurons that release serotonin reside in the brainstem cardiorespiratory control centres and may be affected by FGR. At two time points in the last trimester of sheep brain development, 110 and 127 days of gestation (0.74 and 0.86 of gestation), we assessed histopathological alterations in the brainstem cardiorespiratory control centres of the pons and medulla in early-onset FGR versus control fetal sheep. The FGR cohort were hypoxaemic and asymmetrically growth restricted. Compared to the controls, the brainstem of FGR fetuses exhibited signs of neuropathology, including elevated cell death and reduced cell proliferation, grey and white matter deficits, and evidence of oxidative stress and neuroinflammation. FGR brainstem pathology was predominantly observed in the medullary raphé nuclei, hypoglossal nucleus, nucleus ambiguous, solitary tract and nucleus of the solitary tract. The FGR groups showed imbalanced brainstem serotonin and serotonin 1A receptor abundance in the medullary raphé nuclei, despite evidence of increased serotonin staining within vascular regions of placentomes collected from FGR fetuses. Our findings demonstrate both early and adaptive brainstem neuropathology in response to placental insufficiency. KEY POINTS: Early-onset fetal growth restriction (FGR) was induced in fetal sheep, resulting in chronic fetal hypoxaemia. Growth-restricted fetuses exhibit persistent neuropathology in brainstem nuclei, characterised by disrupted cell proliferation and reduced neuronal cell number within critical centres responsible for the regulation of cardiovascular and respiratory functions. Elevated brainstem inflammation and oxidative stress suggest potential mechanisms contributing to the observed neuropathological changes. Both placental and brainstem levels of 5-HT were found to be impaired following FGR.

Utility of placental biomarkers and fetoplacental Dopplers in predicting likely placental pathology in early and late fetal growth restriction - A prospective study

INTRODUCTION

The aim of this study was to evaluate the association between placental abnormalities, placental biomarkers, and fetoplacental Dopplers in a cohort of pregnancies complicated by fetal growth restriction (FGR). We also ascertained the risk of perinatal mortality, severe neurological morbidity, and severe non-neurological morbidity by type of placental abnormality.

METHODS

This was a prospective cohort study. Multivariable logistic regression was used to evaluate the effect of early vs. late FGR, placental biomarkers and fetoplacental Dopplers on Maternal Vascular Malperfusion (MVM) which was the commonest placental abnormality identified.

RESULTS

There were 161 (53.5 %) early FGR and 140 (46.5 %) late FGR cases. MVM abnormalities were present in 154 (51.2 %), VUE in 45 (14.6 %), FVM in 16 (5.3 %), DVM in 14 (4.7 %) and CHI in 4 (1.3 %) cases. The odds of MVM were higher in early compared to late FGR cohort (OR 1.89, 95%CI 1.14, 3.14, p = 0.01). Low maternal PlGF levels <100 ng/L (OR 2.34, 95%CI 1.27,4.31, p = 0.01), high sFlt-1 level (OR 2.13, 95%CI 1.35, 3.36, p = 0.001) or elevated sFlt-1/PlGF ratio (OR 3.48, 95%CI 1.36, 8.91, p = 0.01) were all associated with MVM. Increased UA PI > 95th centile (OR 2.91, 95%CI 1.71, 4.95, p=<0.001) and mean UtA PI z-score (OR 1.74, 95%CI 1.15, 2.64, p = 0.01) were associated with higher odds of MVM. Rates of severe non-neurological morbidity were highest in the MVM, FVM, and CHI cohorts (44.8 %, 50 %, and 50 % respectively).

CONCLUSION

MVM was the commonest placental abnormality in FGR, particularly in early-onset disease. Low maternal PlGF levels, high sFlt-1 levels, elevated sFlt-1/PlGF ratio, and abnormal fetoplacental Dopplers were also significantly associated with MVM. MVM, FVM, and CHI abnormalities were associated with lower median birthweight, higher rates of preterm birth, operative birth for non-reassuring fetal status, and severe neonatal non-neurological morbidity.

Adverse perinatal outcomes are strongly associated with degree of abnormality in uterine artery Doppler pulsatility index

OBJECTIVE

To investigate the association between varying degrees of abnormality in the Doppler uterine artery pulsatility index (UtA-PI) and adverse perinatal outcome.

METHODS

This was a prospective study of women with a singleton, non-anomalous pregnancy in whom UtA-PI was measured universally in midpregnancy and who gave birth in Oxford University Hospitals, Oxford, UK, between 2016 and 2023. Relative risk ratios (RRR) for the primary outcomes of extended perinatal mortality and live birth with a severe small-for-gestational-age (SGA) neonate were calculated using multinomial logistic regression, for early preterm birth (before 34 + 0 weeks' gestation) and late preterm/term birth (at or after 34 + 0 weeks). Risks were also investigated for iatrogenic preterm birth and a composite adverse outcome before 34 + 0 weeks.

RESULTS

Overall, 33 364 pregnancies were included in the analysis. Compared to those with a normal UtA-PI, the risk of extended perinatal mortality with delivery before 34 + 0 weeks was higher in women with UtA-PI ≥ 90th percentile (RRR, 4.7 (95% CI, 2.7-8.0); P < 0.001), but this was not demonstrated in births at or after 34 + 0 weeks. The risk of live birth with severe SGA was associated strongly with abnormal UtA-PI for early births (RRR, 26.0 (95% CI, 11.6-58.2); P < 0.001) and later births (RRR, 2.3 (95% CI, 1.8-2.9); P < 0.001). Women with raised UtA-PI were more likely to have an early iatrogenic birth (RRR, 7.8 (95% CI, 5.5-11.2); P < 0.001). For each outcome before 34 + 0 weeks and the composite outcome, the risk increased significantly in association with the degree of abnormality in the UtA-PI (from < 90th, 90-94th, 95-98th to ≥ 99th percentile) (Ptrend < 0.001). When using the 90th percentile as opposed to the 95th, there was a significant improvement in the overall predictive accuracy (as determined by the area under the receiver-operating-characteristics curve) for the composite adverse outcome (χ2 = 6.64, P = 0.01) and iatrogenic preterm birth (χ2 = 4.10, P = 0.04).

CONCLUSIONS

Elevated UtA-PI is a key predictor of iatrogenic preterm birth, severe SGA and perinatal loss up to 34 + 0 weeks' gestation. The 90th percentile for UtA-PI should be used, and management should be tailored according to the degree of abnormality, as pregnancies with very raised UtA-PI measurement constitute a group at extreme risk of adverse outcome. © 2024 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Placental pathology lesions: International Society for Ultrasound in Obstetrics and Gynecology vs Society for Maternal-Fetal Medicine fetal growth restriction definitions

BACKGROUND

Research on the definition of fetal growth restriction (FGR) has focused on predicting adverse perinatal outcomes. A significant limitation of this approach is that the individual outcomes of interest could be related to the condition and the treatment. Evaluation of outcomes that reflect the pathophysiology of FGR may overcome this limitation.

OBJECTIVE

To compare the diagnostic performance of the FGR definitions established by the International Society for Ultrasound in Obstetrics and Gynecology (ISUOG) and the Society for Maternal-Fetal Medicine (SMFM) to predict placental histopathological findings associated with placental insufficiency and a composite adverse neonatal outcome (ANeO).

STUDY DESIGN

In this retrospective cohort study of singleton pregnancies, the ISUOG and the SMFM guidelines were used to identify pregnancies with FGR and a corresponding control group. The primary outcome was the prediction of placental histopathological findings associated with placental insufficiency, defined as lesions associated with maternal vascular malperfusion (MVM). A composite ANeO (ie, umbilical artery pH≤7.1, Apgar score at 5 minutes ≤4, neonatal intensive care unit admission, hypoglycemia, respiratory distress syndrome requiring mechanical ventilation, intrapartum fetal distress requiring expedited delivery, and perinatal death) was investigated as a secondary outcome. Sensitivity, specificity, positive and negative predictive values, and the areas under the receiver-operating-characteristics curves were determined for each FGR definition. Logistic regression models were used to assess the association between each definition and the studied outcomes. A subgroup analysis of the diagnostic performance of both definitions stratifying the population in early and late FGR was also performed.

RESULTS

Both societies' definitions showed a similar diagnostic performance as well as a significant association with the primary (ISUOG adjusted odds ratio 3.01 [95% confidence interval 2.42, 3.75]; SMFM adjusted odds ratio 2.85 [95% confidence interval 2.31, 3.51]) and secondary outcomes (ISUOG adjusted odds ratio 1.95 [95% confidence interval 1.56, 2.43]; SMFM adjusted odds ratio 2.12 [95% confidence interval 1.70, 2.65]). Furthermore, both FGR definitions had a limited discriminatory capacity for placental histopathological findings of MVM and the composite ANeO (area under the receiver-operating-characteristics curve ISUOG 0.63 [95% confidence interval 0.61, 0.65], 0.59 [95% confidence interval 0.56, 0.61]; area under the receiver-operating-characteristics SMFM 0.63 [95% confidence interval 0.61, 0.66], 0.60 [95% confidence interval 0.57, 0.62]).

CONCLUSION

The ISUOG and the SMFM FGR definitions have limited discriminatory capacity for placental histopathological findings associated with placental insufficiency and a composite ANeO. El resumen está disponible en Español al final del artículo.

Placental correlates in categories of preterm births based on gestational age

Placental abnormalities can precipitate preterm birth (PTB), a principal contributor to neonatal morbidity and mortality. This study targets understanding placental variations among different gestational age-based categories of PTB.

METHODS

A three-year retrospective study conducted a detailed clinicopathological analysis of PTB placentas categorized by gestational age: extremely preterm (EPTB,<28 weeks), very preterm (VPTB, 28 to 31 + 6 weeks), moderate preterm (MPTB, 32 to 33 + 6 weeks), and late preterm (LPTB, 34 to 36 + 6 weeks). Macroscopic parameters sourced from pathology records and microscopic examination assessed for maternal and fetal stromal-vascular lesions, inflammatory and hypoxic lesions and others. Stillbirths/intrauterine demise and multifetal gestation were excluded. Clinical data were gathered from medical records.

RESULTS

A total of 645 preterm placentas were received and 538 were included. The majority were LPTB(46.3 %), while EPTB, VPTB and MPTB accounted for 5.8 %, 28.4 % and 19.5 % respectively. Low birth weight and low Apgar were prevalent in EPTB(p < 0.001), while obstetric complications were higher in other PTB categories. Placental infarction was higher in VPTB and MPTB(p = 0.006). On microscopy, maternal (48.4 %), fetal (29 %) inflammatory response and villous edema (48.4 %) was higher in EPTB(p = 0.04 & p < 0.001 respectively), while maternal stromal-vascular lesions were higher in VPTB and MPTB(67.3 % & 64.8 %, p < 0.001). Delayed villous maturation (17.7 %,p = 0.02), chronic chorioamnionitis (11.3 %,p = 0.02), membrane hypoxia (38.6 %,p = 0.007), and massive fibrin deposition (10.8 %,p < 0.001) featured higher in LPTB.

DISCUSSION

Acute inflammatory pathology was common in EPTB, strongly suggesting inflammation in triggering parturition. Frequent obstetric complications and maternal stromal-vascular lesions in VPTB and MPTB may underscore maternal vascular compromise in this group. Villous maturation defects, chronic chorioamnionitis, massive fibrin deposition and membrane hypoxia in LPTB, likely contribute to long-term neonatal morbidity.

Late-onset fetal growth restriction management: a national survey

BACKGROUND

Fetal growth restriction (FGR) is an obstetric condition that increases the risk of adverse neonatal outcomes. FGR antenatal care aims to decrease fetal morbidity and mortality through optimal fetal monitoring. However, no univocal strategies for late-onset FGR outpatient management are available, and this survey investigated gynaecologists' attitudes concerning outpatient frequency tests.

METHODS

We mailed a survey to 429 Italian gynaecologists. The primary purpose was the ambulatory care of late-onset FGR without doppler alterations evaluation. The queries estimated the self-reported medical practice regarding cardiotocography (CTG) and obstetric ultrasound exams before hospitalization. Statistical analysis was performed with Stata 14.1 (Stata corp., College Station, TX, USA) for symmetrically distributed continuous variables, and the mean differences were analyzed using the t-test. Where appropriate, the proportions between the groups were evaluated using Fisher's exact or χ2 test. All P value <0.05 were considered statistically significant.

RESULTS

128 responses (29.8%) from the 429 SCCAL members were available for the survey. 39.9% of respondents had a late FGR standardized protocol. Regarding non-severe FGR with normal fetal doppler, 70.8% suggested a fetal doppler study after one week (92/128), 13.8% (18/128) and 6.9% (9/128) proposed the exam, respectively, two and three times for a week. 0.8% (1/128) of respondents had a daily doppler exam, 7.7% (10/128) did not answer, and 3.1% (4/128) repeated the ultrasound exam to time for a week. The antenatal CTG was offered: 70.8% (92/128) of gynaecologists recommended one weekly CTG, whereas 13.8% (18/128) suggested two. 6.9% (9/128) recommended three weekly tests and 0.8% a daily test. 7.7% (10/128) of gynaecologists did not respond. At least, we investigated the gynaecologist's recommendations for outpatient EFW evaluation: 59.4% (76/128) repeated EFW after two weeks, 31.3% (40/128) after one week. 3.9% (4/128) and 3.1 (4/128) recommended EFW after three weeks and twice a week.

CONCLUSIONS

Gynaecologists recommend unnecessary cardiotocography and ultrasound Doppler exams for non-severe late-onset FGR with normal doppler. However, additional studies and comprehensive surveys are needed to support a standardized protocol and assess the feto-maternal outcomes impact.

Placental MFSD2A expression in fetal growth restriction and maternal and fetal DHA status

INTRODUCTION

Fetal growth restriction (FGR) may affect placental transfer of key nutrients to the fetus, such as the fatty acid docosahexaenoic acid (DHA). Major facilitator superfamily domain containing 2A (MFSD2A) has been described as a specific DHA carrier in placenta, but its expression has not been studied in FGR. The aim of this study was to evaluate for the first time the placental MFSD2A levels in late-FGR pregnancies and the maternal and cord plasma DHA.

METHODS

87 pregnant women from a tertial reference center were classified into late-FGR (N = 18) or control (N = 69). Fatty acid profile was determined in maternal and cord venous plasma, as well as placental levels of MFSD2A and of insulin mediators like phospho-protein kinase B (phospho-AKT) and phospho-extracellular regulated kinase (phospho-ERK).

RESULTS

Maternal fatty acid profile did not differ between groups. Nevertheless, late-FGR cord vein presented higher content of saturated fatty acids than control, producing a concomitant decrease in the percentage of some unsaturated fatty acids. In the late-FGR group, a lower DHA fetal/maternal ratio was observed when using percentages, but not with concentrations. No alterations were found in the expression of MFSD2A in late-FGR placentas, nor in phospho-AKT or phospho-ERK.

DISCUSSION

MFSD2A protein expression was not altered in late-FGR placentas, in line with no differences in cord DHA concentration between groups. The increase in the saturated fatty acid content of late-FGR cord might be a compensatory mechanism to ensure fetal energy supply, decreasing other fatty acids percentage. Future studies are warranted to elucidate if altered saturated fatty acid profile in late-FGR fetuses might predispose them to postnatal catch-up and to long-term health consequences.

Mesenchymal stem cell secretome ameliorates over-expression of soluble fms-like tyrosine kinase-1 (sFlt-1) and fetal growth restriction (FGR) in animal SLE model

INTRODUCTION

In the near future, stem cell research may lead to several major therapeutic innovations in medical practice. Secretome, a "by-product" of stem cell line cultures, has many advantages. Its easiness of storage, usage, and fast direct effect are some of those to consider. Fetal growth restriction (FGR) remains one of the significant challenges in maternal-fetal and neonatal medicine. Placentation failure is one of the most profound causal and is often related to increasing sFlt-1 in early pregnancy. This study aimed to investigate hUC-MSC secretome in ameliorating sFlt-1 and how to improve outcomes in preventing FGR in an animal model.

MATERIALS AND METHODS

Pristane-induced systemic lupus erythematosus (SLE) in a mouse model was used to represent placentation failure and its consequences. Twenty-one mice were randomized into three groups: (I) normal pregnancy, (II) SLE, and (III) SLE with secretome treatment. Pristane was administered in all Groups four weeks prior mating period. Secretome was derived from human umbilical cord mesenchymal stem cells (hUC-MSC) conditioned medium on the 3rd and 4th passage, around day-21 until day-28 from the start of culturing process. Mesenchymal stem cell was characterized using flow cytometry for CD105+, CD90+, and CD73+ surface antigen markers. Immunohistochemistry anlysis by using Remmele's Immunoreactive Score (IRS) was used to quantify the placental sFlt-1 expression in each group. Birth weight and length were analyzed as the secondary outcome. The number of fetuses obtained was also calculated for pregnancy loss comparison between Groups.

RESULTS

The administration of secretome of hUC-MSC was found to lower the expression of the placental sFlt-1 significantly in the pristane SLE animal model (10.30 ± 1.40 vs. 4.98 ± 2.57; p < 0.001) to a level seen in normal mouse pregnancies in Group I (3.88 ± 0.49; p = 0.159). Secretome also had a significant effect on preventing fetal growth restriction in the pristane SLE mouse model (birth weight: 354.29 ± 80.76 mg vs. 550 ± 64.03 mg; p < 0.001 and birth length: 14.43 ± 1.27 mm vs. 19.00 ± 1.41 mm), comparable to the birth weight and length of the normal pregnancy in Group I (540.29 ± 75.47 mg and 18.14 ± 1.34 mm, p = 0.808 and = 0.719). Secretome administration also showed a potential action to prevent high number of pregnancy loss as the number of fetuses obtained could be similar to those of mice in the normal pregnant Group (7.71 ± 1.11 vs. 7.86 ± 1.06; p = 0.794).

CONCLUSIONS

Administration of secretome lowers sFlt-1 expression in placenta, improves fetal growth, and prevents pregnancy loss in a mouse SLE model.

Placental Pathology and Its Associations With Clinical Signs in Different Subtypes of Fetal Growth Restriction

OBJECTIVE

We evaluated placental alterations in different subtypes of fetal growth restriction (FGR) to determine any clinical associations.

METHODS

FGR placentas classified according to the Amsterdam criteria were correlated with clinical findings. Percentage of intact terminal villi and villous capillarization ratio were calculated in each specimen. Correlations of placental histopathology and perinatal outcomes were studied. 61 FGR cases were studied.

RESULTS

Early-onset-FGR was more often associated with preeclampsia and recurrence than late-onset-FGR; placentas from early-onset-FGR often had diffuse maternal (or fetal) vascular malperfusion and villitis of unknown etiology. Decreased percentage of intact terminal villi was associated with pathologic CTG. Decreased villous capillarization was associated with early-onset-FGR and birth weight below the second percentile. Avascular villi and infarction were more common when femoral length/abdominal circumference ratio was >0.26, and perinatal outcome was poor in this group.

CONCLUSION

In early-onset-FGR and preeclamptic FGR, altered vascularization of villi may have a key role in pathogenesis, and recurrent FGR is associated with villitis of unknown etiology. There is an association between femoral length/abdominal circumference ratio >0.26 and histopathological alterations of placenta in FGR pregnancies. There are no significant differences in the percentage of intact terminal villi between different FGR subtypes by onset or recurrency.

Placental pathology in pregnancies with late fetal growth restriction and abnormal cerebroplacental ratio

INTRODUCTION

Late fetal growth restriction (FGR) is associated with mild growth restriction and normal or mild abnormal doppler flows. The cerebroplacental ratio (CPR) has been demonstrated as more sensitive to hypoxia than its individual components in these fetuses. We hypothesized that abnormal CPR in late FGR is reflected in specific placental vascular malperfusion lesions.

METHODS

Retrospective cohort study of late FGR newborns between 2012 and 2022 in a tertiary hospital. Overall, 361 cases were included: 104 with pathological CPR (study group), and 257 with normal doppler flows (control group). The primary outcome was a composite of maternal vascular malperfusion lesions (MVM) and fetal vascular malperfusion lesions (FVM). Secondary outcomes were macroscopic placental characteristics and various obstetrical and neonatal outcomes.

RESULTS

The study group had lower birthweight compared with the normal CPR group (2063.5 ± 470.5 vs. 2351.6 ± 387.4 g. P < 0.0001), higher rates of composite adverse neonatal outcomes (34.2% vs. 22.5%, p < 0.0001), lower mean placental weight (318 ± 71.6 vs. 356.6 ± 76.5 g, p < 0.0001), as well as a higher prevalence of Vascular lesions of MVM (15.3% vs. 5.0%, p = 0.002), villous lesions of FVM (37.5% vs. 24.9%, p = 0.02), and composite FVM lesions (36.5% vs. 25.6%, p = 0.04). On multivariate regression analysis for MVM lesions and composite FVM lesions, abnormal CPR was found as an independent risk factor (aOR 2.17, 95% CI 1.63-4.19, and aOR 1.31, 95% CI 1.09-3.97, respectively).

DISCUSSIONS

Abnormal CPR in late FGR is reflected in placental histopathologic vascular malperfusion lesions, and the incidence of these lesions is higher than in FGR placentas with normal CPR.

Appropriate Delivery Timing in Fetuses with Fetal Growth Restriction to Reduce Neonatal Complications: A Case-Control Study in Romania

(1) Background: The main challenge in cases of early onset fetal growth restriction is management (i.e., timing of delivery), trying to determine the optimal balance between the opposing risks of stillbirth and prematurity. The aim of this study is to determine the likelihood of neonatal complications depending on the time of birth based on Doppler parameters in fetuses with early onset fetal growth restriction; (2) Methods: A case-control study of 205 consecutive pregnant women diagnosed with early onset FGR was conducted at the Obstetrics Clinic of the Municipal Emergency Hospital in Timisoara, Romania; The case group included newborns who were delivered at the onset of umbilical arteries absent/reversed end-diastolic flow, and the control included infants delivered at the onset of reversed/absent ductus venosus A-wave. (3) Results: The overall neonatal mortality rate was 2.0%, and there was no significant statistical difference between the two study groups. In infants delivered up to 30 gestational weeks, grades III/IV intraventricular hemorrhage and bronchopulmonary dysplasia were statistically significantly more frequent in the control group. Moreover, univariate binomial logistic regression analysis on fetuses born under 30 gestational weeks shows that those included in the control group are 30 times more likely to develop bronchopulmonary dysplasia and 14 times more likely to develop intraventricular hemorrhage grades III/IV; (4) Conclusions: Infants delivered according to the occurrence of umbilical arteries absent/reversed end-diastolic flow are less likely to develop intraventricular hemorrhage grades III/IV and bronchopulmonary dysplasia.

Is there an association between isolated sonographic abdominal circumference below the 10th percentile and placental vascular lesions?

OBJECTIVE

To study the association between prenatal diagnosis of isolated abdominal circumference (AC) below the 10th percentile (AC <10th) in appropriate for gestational age (AGA) neonates and placental vascular lesions.

METHODS

A prospective study was conducted of healthy women who underwent sonographic fetal biometric measurements, up to 7 days before delivery, and delivered AGA neonates. The study cohort was divided into those with and without prenatal isolated AC <10th. Placental histopathology lesions were classified into maternal and fetal vascular malperfusion (MVM, FVM) lesions.

RESULTS

Compared to the AC over 10th percentile group (n = 85), the AC <10th group (n = 85) was characterized by lower maternal body mass index, higher rate of smokers, and increased rate of induced labor (P = 0.029, P = 0.029, P = 0.001, respectively). There were no between-group differences regarding maternal age, gestational age, and neonatal outcome. Mean placental weight was lower in the isolated AC <10th (P < 0.001). The rate of MVM or FVM lesions did not differ between the groups. By multivariate logistic regression analysis, isolated AC <10th was not found to be associated with increased risk for placental vascular lesions.

CONCLUSION

Isolated AC <10th is associated with increased rate of induction of labor; however, it is not associated with increased placental vascular lesions.

Acute Histological Chorioamnionitis and Birth Weight in Pregnancies With Preterm Prelabor Rupture of Membranes: A Retrospective Cohort Study

Aim: To assess the association between the birth weight of newborns from pregnancies with preterm prelabor rupture of membranes (PPROM) and the presence of acute histological chorioamnionitis (HCA) with respect to the: i) fetal and maternal inflammatory responses and ii) acute inflammation of the amnion.

Material and Methods: This retrospective cohort study included 818 women with PPROM. A histopathological examination of the placenta was performed. Fetal inflammatory response was defined as the presence of any neutrophils in umbilical cord (histological grades 1–4) and/or chorionic vasculitis (histological grade 4 for the chorionic plate). Maternal inflammatory response was defined as the presence of histological grade 3–4 for the chorion-decidua and/or grade 3 for the chorionic plate and/or grade 1–4 for the amnion. Acute inflammation of the amnion was defined as the presence of any neutrophils in the amnion (histological grade 1–4 for the amnion). Birth weights of newborns were expressed as percentiles derived from INTERGROWTH-21st standards for the i) estimated fetal weight and ii) newborn birth weight.

Results: No difference in percentiles of birth weights of newborns was found among the women with the women with HCA with fetal inflammatory response, with HCA with maternal inflammatory response and those without HCA. Women with HCA with acute inflammation of the amnion had lower percentiles of birth weights of newborns, derived from the estimated fetal weight standards, than women with HCA without acute inflammation of the amnion and those with the absence of HCA in the crude (with acute inflammation: median 46, without acute inflammation: median 52, the absence of HCA: median 55; p = 0.004) and adjusted (p = 0.02) analyses. The same subset of pregnancies exhibited the highest rate of newborns with a birth weight of ≤25 percentile. When percentiles were derived from the newborn weight standards, no differences in birth weights were observed among the subgroups.

Conclusion: Acute inflammation of the amnion was associated with a lower birth weight in PPROM pregnancies, expressed as percentiles derived from the estimated fetal weight standards.

Should twin-specific growth charts be used to assess fetal growth in twin pregnancies?

One of the hallmarks of twin pregnancies is the slower rate of fetal growth when compared with singleton pregnancies during the third trimester. The mechanisms underlying this phenomenon and whether it represents pathology or benign physiological adaptation are currently unclear. One important implication of these questions relates to the type growth charts that should be used by care providers to monitor growth of twin fetuses. If the slower growth represents pathology (ie, intrauterine growth restriction caused uteroplacental insufficiency), it would be preferable to use a singleton growth chart to identify a small twin fetus that is at risk for perinatal mortality and morbidity. If, however, the relative smallness of twins is the result of benign adaptive mechanisms, it is likely preferable to use a twin-based charts to avoid overdiagnosis of intrauterine growth restriction in twin pregnancies. In the current review, we addressed this question by describing the differences in fetal growth between twin and singleton pregnancies, reviewing the current knowledge regarding the mechanisms responsible for slower fetal growth in twins, summarizing available empirical evidence on the diagnostic accuracy of the 2 types of charts for intrauterine growth restriction in twin pregnancies, and addressing the question of whether uncomplicated dichorionic twins are at an increased risk for fetal death when compared with singleton fetuses. We identified a growing body of evidence that shows that the use of twin charts can reduce the proportion of twin fetuses identified with suspected intrauterine growth restriction by up to 8-fold and can lead to a diagnosis of intrauterine growth restriction that is more strongly associated with adverse perinatal outcomes and hypertensive disorders than a diagnosis of intrauterine growth restriction based on a singleton-based chart without compromising the detection of twin fetuses at risk for adverse outcomes caused by uteroplacental insufficiency. We further found that small for gestational age twins are less likely to experience adverse perinatal outcomes or to have evidence of uteroplacental insufficiency than small for gestational age singletons and that recent data question the longstanding view that uncomplicated dichorionic twins are at an increased risk for fetal death caused by placental insufficiency. Overall, it seems that, based on existing evidence, the of use twin charts is reasonable and may be preferred over the use of singleton charts when monitoring the growth of twin fetuses. Still, it is important to note that the available data have considerable limitations and are primarily derived from observational studies. Therefore, adequately-powered trials are likely needed to confirm the benefit of twin charts before their use is adopted by professional societies.

Intra-amniotic inflammation and birth weight in pregnancies with preterm labor with intact membranes: A retrospective cohort study

OBJECTIVE

To assess the association between newborn birth weight and the presence of intra-amniotic infection, presence of sterile intra-amniotic inflammation, and absence of intra-amniotic inflammation in pregnancies with preterm labor with intact membranes.

METHODS

A total of 69 pregnancies with preterm labor with intact membranes between gestational ages 22 + 0 and 34 + 6 weeks who delivered within seven days of admission were included in this retrospective cohort study. Transabdominal amniocentesis to determine the presence of microorganisms and/or their nucleic acids in amniotic fluid (through culturing and molecular biology methods) and intra-amniotic inflammation (according to amniotic fluid interleukin-6 concentrations) were performed as part of standard clinical management. The participants were further divided into three subgroups: intra-amniotic infection (presence of microorganisms and/or nucleic acids along with intra-amniotic inflammation), sterile intra-amniotic inflammation (intra-amniotic inflammation alone), and without intra-amniotic inflammation. Birth weights of newborns were expressed as percentiles derived from the INTERGROWTH-21st standards for (i) estimated fetal weight and (ii) newborn birth weight.

RESULTS

No difference in birth weights, expressed as percentiles derived from the standard for estimated fetal weight, was found among the women with intra-amniotic infection, with sterile intra-amniotic inflammation, and without intra-amniotic inflammation (with infection, median 29; with sterile inflammation, median 54; without inflammation, median 53; p = 0.06). Differences among the subgroups were identified in the birth weight rates, expressed as percentiles derived from the standard for estimated fetal weight, which were less than the 10th percentile (with infection: 20%, with inflammation: 13%, without inflammation: 0%; p = 0.04) and 25th percentile (with infection: 47%, with inflammation: 31%, without inflammation: 9%; p = 0.01). No differences among the subgroups were observed when percentiles of birth weight were derived from the birth weight standard.

CONCLUSIONS

The presence of intra-amniotic inflammatory complications in pregnancies with preterm labor with intact membranes prior to the gestational age of 35 weeks was associated with a higher rate of newborns with birth weight less than the 10th and 25th percentile, when percentiles of birth weight were derived from the standard for estimated fetal weight.

Recent research on the influence of intrauterine growth restriction on the structure and function of the nervous system

Intrauterine growth restriction (IUGR) is caused by many factors, and most newborns with IUGR are small for gestational age (SGA). SGA infants have a relatively high risk of death and disease in the perinatal period, and the nervous system already has structural changes in the uterus, including the reduction of brain volume and gray matter volume, accompanied by abnormal imaging and pathological changes. IUGR fetuses undergo intrauterine blood flow redistribution to protect brain blood supply, and there are still controversies over the clinical effect of brain protection mechanism. SGA infants have a relatively high risk of abnormal cognitive, motor, language, and behavioral functions in the neonatal period and childhood, and preterm infants tend to have a higher degree of neurological impairment than full-term infants. Early intervention may help to improve the function of the nervous system.

How and when to recommend delivery of a growth-restricted fetus: A review

Clinicians consider a range of variables when formulating decisions regarding the diagnosis, monitoring plan, and ultimately the decision to recommend the delivery of a growth-restricted fetus. The differential diagnosis of a pathological fetal growth pattern is initially considered via the history, a physical and laboratory examination of the pregnant person, as well as a comprehensive fetal ultrasound examination. These factors allow a broad distinction between pre-existing disease in the pregnant person, constitutionally small normal growth, placenta-mediated Fetal Growth Restriction (FGR), and intrinsic fetal disease. Most commonly, pathological growth restriction is mediated by underlying placental diseases, of which maternal vascular malperfusion is the most common, and often results in co-existent hypertension. A program of combined monitoring of the pregnant person and fetus, comprising hypertension assessment, and serial fetal ultrasound, including Doppler studies is then instituted, and may be combined with biochemical markers, such as Placental Growth Factor, for greater clinical precision. Recommendations on timing to deliver the growth-restricted fetus worldwide are converging, with similar guidance from clinical practice guidelines informed by high-quality Randomized Controlled Trials (RCTs) and large cohort studies. In most instances, it is reasonable to recommend delivery of all growth-restricted fetuses by approximately 38 weeks. Timing of delivery should take into consideration both short-term neonatal outcomes and long-term outcomes at school age. Mode of delivery is based on many factors, and induction of labor is a safe approach, especially after 34 weeks. Mechanical methods of induction may be preferred to pharmacologic methods, although both have a role and the choice of method is based on individualized assessment. Elective Cesarean birth thereby bypassing fetal stress during labor, is recommended in preterm growth-restricted fetuses with signs of adaptive fetal compromise, especially when ductus venosus flow is abnormal, or a contraction stress test is positive.

Placenta-specific Slc38a2/SNAT2 knockdown causes fetal growth restriction in mice

Fetal growth restriction (FGR) is a complication of pregnancy that reduces birth weight, markedly increases infant mortality and morbidity and is associated with later-life cardiometabolic disease. No specific treatment is available for FGR. Placentas of human FGR infants have low abundance of sodium-coupled neutral amino acid transporter 2 (Slc38a2/SNAT2), which supplies the fetus with amino acids required for growth. We determined the mechanistic role of placental Slc38a2/SNAT2 deficiency in the development of restricted fetal growth, hypothesizing that placenta-specific Slc38a2 knockdown causes FGR in mice. Using lentiviral transduction of blastocysts with a small hairpin RNA (shRNA), we achieved 59% knockdown of placental Slc38a2, without altering fetal Slc38a2 expression. Placenta-specific Slc38a2 knockdown reduced near-term fetal and placental weight, fetal viability, trophoblast plasma membrane (TPM) SNAT2 protein abundance, and both absolute and weight-specific placental uptake of the amino acid transport System A tracer, 14C-methylaminoisobutyric acid (MeAIB). We also measured human placental SLC38A2 gene expression in a well-defined term clinical cohort and found that SLC38A2 expression was decreased in late-onset, but not early-onset FGR, compared with appropriate for gestational age (AGA) control placentas. The results demonstrate that low placental Slc38a2/SNAT2 causes FGR and could be a target for clinical therapies for late-onset FGR.

Doppler abnormalities and perinatal outcomes in pregnant women with early-onset fetal growth restriction

OBJECTIVE

To compare Doppler alterations and perinatal outcomes in pregnant women who evolved with early- and late-onset fetal growth restriction (FGR).

METHODS

A retrospective, observational cohort study with pregnant women who evolved with FGR treated between January 2018 and April 2019, in which all live births from singleton pregnancies, over 24 weeks, with FGR ultrasound diagnosis and under 2700 g weight were included in the study.

RESULTS

Pregnancies with early-onset FGR were more associated with hypertensive disorders (p = .00) and placental vascular insufficiency, resulting in a high degree of umbilical artery Doppler involvement (p = .00) in a short period of pregnancy and higher rates of adverse perinatal outcomes (p = .00). The time of prenatal follow-up of early- and late-onset FGR cases was similar, but the degree of prematurity of the former made the evolution more unfavorable.

CONCLUSION

Early-onset FGR had a lower prevalence but was associated with higher maternal and fetal morbidity and mortality than late-onset FGR.

Neurodevelopment of infant with late fetal growth restriction

Late fetal growth restriction has increasingly gain interest. Differently from early fetal growth restriction, the severity of this condition and the impact on perinatal mortality and morbidity is less severe. Nevertheless, there is some evidence to suggest that fetuses exposed to growth restriction late in pregnancy are at increased risk of neurological dysfunction and behavioral impairment. The aim of our review was to discuss the available evidence on the neurodevelopmental outcome in fetuses exposed to growth restriction late in pregnancy. Cerebral blood flow redistribution, a Doppler hallmark of late fetal growth restriction, has been associated with this increased risk, although there are still some controversies. Currently, most of the available studies are heterogeneous and do not distinguish between early and late fetal growth restriction when evaluating the long-term outcome, thus, making the correlation between late fetal growth restriction and neurological dysfunction difficult to interpret. The available evidence suggests that fetuses exposed to late growth restriction are at increased risk of neurological dysfunction and behavioral impairment. The presence of the cerebral blood flow redistribution seems to be associated with adverse neurodevelopmental outcome, however, from the present literature the causality cannot be ascertained.

How to define late fetal growth restriction

A fraction of third-trimester small fetuses does not achieve their endowed growth potential mainly due to placental insufficiency, usually not evident in terms of impaired umbilical artery Doppler, but severe enough to increase the risk of perinatal adverse outcomes and long-term complications. The identification of those fetuses at higher-risk helps to optimize their follow-up and to decrease the risk of intrauterine demise. Several parameters can help in the identification of those fetuses at higher risk, defined as fetal growth restricted (FGR) fetuses. Severe smallness and the cerebroplacental ratio are the most consistent parameters; regarding uterine artery Doppler, although some evidence in favour has been published, there is currently no consensus about its use. Thirty-two weeks of gestation is the accepted cut-off to define late FGR. The differentiation with early FGR is necessary as these two entities have different clinical maternal manifestations, and different associated short-term and long-term neonatal outcomes. The use of angiogenic factors is promising but more research is needed on this field.

FIGO (international Federation of Gynecology and obstetrics) initiative on fetal growth: best practice advice for screening, diagnosis, and management of fetal growth restriction

Fetal growth restriction (FGR) is defined as the failure of the fetus to meet its growth potential due to a pathological factor, most commonly placental dysfunction. Worldwide, FGR is a leading cause of stillbirth, neonatal mortality, and short- and long-term morbidity. Ongoing advances in clinical care, especially in definitions, diagnosis, and management of FGR, require efforts to effectively translate these changes to the wide range of obstetric care providers. This article highlights agreements based on current research in the diagnosis and management of FGR, and the areas that need more research to provide further clarification of recommendations. The purpose of this article is to provide a comprehensive summary of available evidence along with practical recommendations concerning the care of pregnancies at risk of or complicated by FGR, with the overall goal to decrease the risk of stillbirth and neonatal mortality and morbidity associated with this condition. To achieve these goals, FIGO (the International Federation of Gynecology and Obstetrics) brought together international experts to review and summarize current knowledge of FGR. This summary is directed at multiple stakeholders, including healthcare providers, healthcare delivery organizations and providers, FIGO member societies, and professional organizations. Recognizing the variation in the resources and expertise available for the management of FGR in different countries or regions, this article attempts to take into consideration the unique aspects of antenatal care in low-resource settings (labelled “LRS” in the recommendations). This was achieved by collaboration with authors and FIGO member societies from low-resource settings such as India, Sub-Saharan Africa, the Middle East, and Latin America.

Diagnostic accuracy of fetal growth charts for placenta-related fetal growth restriction

INTRODUCTION

The choice of fetal growth chart to be used in antenatal screening for fetal growth restriction (FGR) has an important impact on the proportion of fetuses diagnosed as small for gestational age (SGA), and on the detection rate for FGR. We aimed to compare diagnostic accuracy of SGA diagnosed using four different common fetal growth charts [Hadlock, Intergrowth-21st (IG21), World Health Organization (WHO), and National Institute of Child Health and Human Development (NICHD)], for abnormal placental pathology.

METHODS

A secondary analysis of data from a prospective cohort study in low-risk nulliparous women. The exposure was SGA (birthweight <10th centile for gestational age) using each of the four charts. The outcomes were one of three types of abnormal placental pathology associated with fetal growth restriction: maternal vascular malperfusion (MVM), chronic villitis, and fetal vascular malperfusion.

RESULTS

A total of 742 nulliparous women met the study criteria. The proportion of SGA was closest to the expected rate of 10% using the Hadlock chart (12.7%). The detection rates (DR) and false positive rates (FPR) for MVM pathology were similar for the Hadlock (DR = 53.1%, FPR = 10.8%), WHO (DR = 59.4%, FPR = 14.2%), and NICHD (DR = 53.1%, FPR = 12.3%) charts, and each was superior when compared to the IG21 chart (DR = 34.4%, FPR = 3.8%, p < 0.001). The diagnosis of SGA was associated with increased risks of preeclampsia and preterm birth for all four charts.

DISCUSSION

The selection of fetal growth chart to be used in screening programs for FGR has important implications with regard to the false positive and detection rate for FGR.

Placental Histopathology and Pregnancy Outcomes in "Early" vs. "Late" Placental Abruption

Placenta-associated pregnancy complications (fetal growth restriction and preeclampsia) are traditionally classified as "early" and "late" due to their different pathophysiology, histopathology, and pregnancy outcomes. As placental abruption (PA) represents another placenta-associated complication, we aimed to study if this categorization can be applied to PA as well. Pregnancy and placental reports of all pregnancies complicated by PA between November 2008 and January 2019 were reviewed. Maternal background, pregnancy outcomes, and placental histopathology were compared between cases of PA < 34 weeks (early PA group) vs. > 34 weeks (late PA group). Placental lesions were classified according to the "Amsterdam" criteria. The primary outcome was severe neonatal morbidity (≥ 1 severe neonatal complications: seizures, IVH, HIE, PVL, blood transfusion, NEC, or death). Included were 305 cases of PA, 71 (23.3%) in the early group and 234 (76.7%) in the late group. The early PA group was characterized by higher rates of vaginal bleeding upon presentation (p = 0.003), DIC (p = 0.018), and severe neonatal morbidity (p < 0.001). The late PA group was characterized by a higher rate of urgent Cesarean deliveries (p < 0.001). The early PA group was characterized by higher rates of placental maternal vascular malperfusion (MVM) lesions (p < 0.001), maternal inflammatory response (MIR) lesions (p < 0.001), placental hemorrhage (p < 0.001), and a lower feto-placental ratio (p < 0.001). Using regression analysis, we found that severe neonatal morbidity was independently associated with early abruption (aOR = 5.3, 95% CI = 3.9-7.6), placental MVM (aOR = 1.5, 95% CI = 1.2-1.9), placental MIR (aOR = 1.9, 95% CI = 1.4-2.3), and inversely associated with antenatal corticosteroids (aOR = 0.9, 95% CI = 0.6-0.98). "Early" and "late" PA significantly differ in their presentation, placental pathology, and pregnancy outcomes.

Identification of the optimal growth chart and threshold for the prediction of antepartum stillbirth

PURPOSE

To evaluate the effect of the choice growth chart and threshold used to define small for gestational age (SGA) on the predictive value of SGA for placenta-related or unexplained antepartum stillbirth.

METHODS

A retrospective cohort study of all women with a singleton pregnancy who gave birth > 24 week gestation in a single center (2000-2016). The exposure of interest was SGA, defined as birth weight < 10th or < 25th centile according to three fetal growth charts (Hadlock et al., Radiology 181:129-133, 1991; intergrowth-21st (IG21), WHO 2017, and a Canadian birthweight-based reference-Kramer et al., Pediatrics 108:E35, 2001). The outcome of interest was antepartum stillbirth due to placental dysfunction or unknown etiology. Cases of stillbirth attributed to other specific etiologies were excluded.

RESULTS

A total of 49,458 women were included in the cohort. There were 103 (0.21%) cases of stillbirth due to placental dysfunction or unknown etiology. For cases in the early stillbirth cluster (≤ 30 weeks), the detection rate was high and was similar for the three ultrasound-based fetal growth charts of Hadlock, IG21, and WHO (range 83.3-87.0%). In contrast, the detection rate of SGA for cases in the late stillbirth cluster (> 30 weeks) was low, being highest for WHO and Hadlock (36.7% and 34.7%, respectively), and lowest for IG21 (18.4%). Using a threshold of the 25th centile increased the detection rate for stillbirth by approximately 15-20% compared with that achieved by the 10th centile cutoff.

CONCLUSION

At > 30 week gestation, the Hadlock or WHO fetal growth charts provided the best balance between detection rate and false positive rate for stillbirth.

Exploring in vivo placental microstructure in healthy and growth-restricted pregnancies through diffusion-weighted magnetic resonance imaging

INTRODUCTION

Gross and microstructural changes in placental development can influence placental function and adversely impact fetal growth and well-being; however, there is a paucity of invivo tools available to reliably interrogate in vivo placental microstructural development. The objective of this study is to characterize invivo placental microstructural diffusion and perfusion in healthy and growth-restricted pregnancies (FGR) using non-invasive diffusion-weighted imaging (DWI).

METHODS

We prospectively enrolled healthy pregnant women and women whose pregnancies were complicated by FGR. Each woman underwent DWI-MRI between 18 and 40 weeks gestation. Placental measures of small (D) and large (D*) scale diffusion and perfusion (f) were estimated using the intra-voxel incoherent motion (IVIM) model.

RESULTS

We studied 137 pregnant women (101 healthy; 36 FGR). D and D* are increased in late-onset FGR, and the placental perfusion fraction, f, is decreased (p < 0.05 for all).

DISCUSSION

Placental DWI revealed microstructural alterations of the invivo placenta in FGR, particularly in late-onset FGR. Early and reliable identification of placental pathology in vivo may better guide future interventions.

Pathologic placental lesions in early and late fetal growth restriction

INTRODUCTION

The purpose of the study was to evaluate the differences in individual histopathologic placental lesions in pregnancies complicated by early-onset (<32 weeks at diagnosis) and late-onset (≥32 weeks at diagnosis) fetal growth restriction (FGR).

MATERIAL AND METHODS

A cohort study of 440 singleton pregnancies complicated by FGR, diagnosed according to standard ultrasonographic criteria, followed up and delivered at the same institution between 2010 and 2016. Placental lesions were classified according to the Amsterdam Placental Workshop Consensus Criteria. Pathologic examination of placentas from 113 healthy singleton term pregnancies served as controls. Binary and multinomial logistic regression models were used to evaluate the independent association of placental lesions with the type of FGR.

RESULTS

In our cohort the prevalences of early and late FGR were 37.3% (164/440) and 62.7% (276/440), respectively. The overall rates of preeclampsia (69/164 vs 59/276, P < 0.01) and absent/reversed umbilical artery pulsatility indices (61/164 vs 14/276, P < 0.001) were higher among early FGR than late FGR. Placental characteristics from early and late FGR pregnancies differed mainly in regard to maternal vascular malperfusion scores rather than fetal scores, with preeclampsia found to be a cofactor modulating the rates and severity of associated lesions. In the binary logistic analysis, recent infarcts (OR 2.44, 95% CI 1.2-5), distal villous hypoplasia (OR 1.8, 95% CI 1.0-3.2), atherosis (OR 2.71, 95% CI 1.35-5.47), persistent endovascular trophoblasts (OR 1.67, 95% CI 1.03-2.7), and a reduced fetal/placental weight score (OR 0.27, 95% CI 0.2-0.38) were independently associated with an increased likelihood of early FGR compared with late FGR. The sensitivity, specificity, and area under the curve of the model were 60% (95% CI 51.2-66.2), 89.1% (95% CI 84.9-92.3), and 0.81 (95% CI 0.77-0.85), respectively, suggesting a fair to good predictive value.

CONCLUSIONS

Individual placental lesions suggestive of increased rates of ischemia, defective remodeling of spiral arteries, peripheral hypoxia interfering with villus development, and reduced placental efficiency were significantly more common in early FGR than late FGR.

Early-onset fetal growth restriction: A systematic review on mortality and morbidity

INTRODUCTION

Severe early-onset fetal growth restriction is an obstetric condition with significant risks of perinatal mortality, major and minor neonatal morbidity, and long-term health sequelae. The prognosis of a fetus is influenced by the extent of prematurity and fetal weight. Clinical care is individually adjusted. In literature, survival rates vary and studies often only include live-born neonates with missing rates of antenatal death. This systematic review aims to summarize the literature on mortality and morbidity.

MATERIAL AND METHODS

A broad literature search was conducted in OVID MEDLINE from 2000 to 26 April 2019 to identify studies on fetal growth restriction and perinatal death. Studies were excluded when all included children were born before 2000 because (neonatal) health care has considerably improved since this period. Studies were included that described fetal growth restriction diagnosed before 32 weeks of gestation and antenatal mortality and neonatal mortality and/or morbidity as outcome. Quality of evidence was rated with the GRADE instrument.

RESULTS

Of the 2604 publications identified, 25 studies, reporting 2895 pregnancies, were included in the systematic review. Overall risk of bias in most studies was judged as low. The quality of evidence was generally rated as very low to moderate, except for 3 large well-designed randomized controlled trials. When combining all data on mortality, in 355 of 2895 pregnancies (12%) the fetus died antenatally, 192 died in the neonatal period (8% of live-born neonates) and 2347 (81% of all pregnancies) children survived. Of the neonatal morbidities recorded, respiratory distress syndrome (34% of the live-born neonates), retinopathy of prematurity (13%) and sepsis (30%) were most common. Of 476 children that underwent neurodevelopmental assessment, 58 (12% of surviving children, 9% of all pregnancies) suffered from cognitive impairment and/or cerebral palsy.

CONCLUSIONS

When combining the data of 25 included studies, survival in fetal growth restriction pregnancies, diagnosed before 32 weeks of gestation, was 81%. Neurodevelopmental impairment was assessed in a minority of surviving children. Individual prognostic counseling on the basis of these results is hampered by differences in patient and pregnancy characteristics within the included patient groups.