Third-trimester ultrasound for antenatal diagnosis of placenta accreta spectrum in women with placenta previa: results from the ADoPAD study

OBJECTIVE

To evaluate the performance of third-trimester ultrasound for the diagnosis of clinically significant placenta accreta spectrum disorder (PAS) in women with low-lying placenta or placenta previa.

METHODS

This was a prospective multicenter study of pregnant women aged ≥ 18 years who were diagnosed with low-lying placenta (< 20 mm from the internal cervical os) or placenta previa (covering the internal cervical os) on ultrasound at ≥ 26 + 0 weeks' gestation, between October 2014 and January 2019. Ultrasound suspicion of PAS was raised in the presence of at least one of these signs on grayscale ultrasound: (1) obliteration of the hypoechogenic space between the uterus and the placenta; (2) interruption of the hyperechogenic interface between the uterine serosa and the bladder wall; (3) abnormal placental lacunae. Histopathological examinations were performed according to a predefined protocol, with pathologists blinded to the ultrasound findings. To assess the ability of ultrasound to detect clinically significant PAS, a composite outcome comprising the need for active management at delivery and histopathological confirmation of PAS was considered the reference standard. PAS was considered to be clinically significant if, in addition to histological confirmation, at least one of these procedures was carried out after delivery: use of hemostatic intrauterine balloon, compressive uterine suture, peripartum hysterectomy, uterine/hypogastric artery ligation or uterine artery embolization. The diagnostic performance of each ultrasound sign for clinically significant PAS was evaluated in all women and in the subgroup who had at least one previous Cesarean section and anterior placenta. Post-test probability was assessed using Fagan nomograms.

RESULTS

A total of 568 women underwent transabdominal and transvaginal ultrasound examinations during the study period. Of these, 95 delivered in local hospitals, and placental pathology according to the study protocol was therefore not available. Among the 473 women for whom placental pathology was available, clinically significant PAS was diagnosed in 99 (21%), comprising 36 cases of placenta accreta, 19 of placenta increta and 44 of placenta percreta. The median gestational age at the time of ultrasound assessment was 31.4 (interquartile range, 28.6-34.4) weeks. A normal hypoechogenic space between the uterus and the placenta reduced the post-test probability of clinically significant PAS from 21% to 5% in women with low-lying placenta or placenta previa in the third trimester of pregnancy and from 62% to 9% in the subgroup with previous Cesarean section and anterior placenta. The absence of placental lacunae reduced the post-test probability of clinically significant PAS from 21% to 9% in women with low-lying placenta or placenta previa in the third trimester of pregnancy and from 62% to 36% in the subgroup with previous Cesarean section and anterior placenta. When abnormal placental lacunae were seen on ultrasound, the post-test probability of clinically significant PAS increased from 21% to 59% in the whole cohort and from 62% to 78% in the subgroup with previous Cesarean section and anterior placenta. An interrupted hyperechogenic interface between the uterine serosa and bladder wall increased the post-test probability for clinically significant PAS from 21% to 85% in women with low-lying placenta or placenta previa and from 62% to 88% in the subgroup with previous Cesarean section and anterior placenta. When all three sonographic markers were present, the post-test probability for clinically significant PAS increased from 21% to 89% in the whole cohort and from 62% to 92% in the subgroup with previous Cesarean section and anterior placenta.

CONCLUSIONS

Grayscale ultrasound has good diagnostic performance to identify pregnancies at low risk of PAS in a high-risk population of women with low-lying placenta or placenta previa. Ultrasound may be safely used to guide management decisions and concentrate resources on patients with higher risk of clinically significant PAS. © 2022 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Fetal Growth Restriction: Does an Integrated Maternal Hemodynamic-Placental Model Fit Better?

In recent years, a growing interest has arisen regarding the possible relationship between adverse pregnancy outcomes (APOs) and inadequate maternal hemodynamic adaptations to the pregnancy. A possible association between "placental syndromes," such as preeclampsia (PE) and fetal growth restriction (FGR), and subsequent maternal cardiovascular diseases (CVD) later in life has been reported. The two subtypes of FGR show different pathogenetic and clinical features. Defective placentation, due to a poor trophoblastic invasion of the maternal spiral arteries, is believed to play a central role in the pathogenesis of early-onset PE and FGR. Since placental functioning is dependent on the maternal cardiovascular system, a pre-existent or subsequent cardiovascular impairment may play a key role in the pathogenesis of early-onset FGR. Late FGR does not seem to be determined by a primary abnormal placentation in the first trimester. The pathological pathway of late-onset FGR may be due to a primary maternal cardiovascular maladaptation: CV system shows a flat profile and remains similar to those of non-pregnant women. Since the second trimester, when the placenta is already developed and increases its functional request, a hypovolemic state could lead to placental hypoperfusion and to an altered maturation of the placental villous tree and therefore to an altered fetal growth. Thus, this review focalizes on the possible relationship between maternal cardiac function and placentation in the development of both early and late-onset FGR. A better understanding of maternal hemodynamics in pregnancies complicated by FGR could bring various benefits in clinical practice, improving screening and therapeutic tools.

How many roads lead to stillbirth rate reduction? A 30-year analysis of risk factors in a Northern Italy University care center

BACKGROUND

Stillbirths affect more than 2.5 million pregnancies worldwide every year and the progress in reducing stillbirth rates is slower than that required by World Health Organization. The aim of the present study was to investigate which factors were associated with stillbirths in a University Hospital in the North of Italy, over a time span of 30 years. The goal was to identify which factors are potentially modifiable to reduce stillbirth rate.

METHODS

Retrospective case-control study (358 stillbirths, 716 livebirths) subdivided into two study periods (1987-2006 and 2007-2017).

RESULTS

The prevalence of conception obtained by assisted reproductive technologies, pregnancy at advanced maternal age, and complications of pregnancy such as preeclampsia, fetal growth restriction (FGR), and other fetal diseases (abnormal fetal conditions including fetal anemia, fetal hydrops, TORCH infections) increased through the years of the study. Despite a rising prevalence, the last 10 years showed a significant reduction in stillbirths associated with preeclampsia and FGR. Similarly, the risk of stillbirth related to abnormal fetal conditions decreased in the second study period and a history of previous stillbirth becomes a nonsignificant risk factor.

CONCLUSIONS

Altogether these results suggest that in pregnancies perceived as "high risk" (i.e. previous stillbirth, preeclampsia, FGR, abnormal fetal conditions) appropriate care and follow-up can indeed lower stillbirth rates. In conclusion, the road to stillbirth prevention passes inevitably through awareness and recognition of risk factors.

Activation of Protein C in Human Trophoblasts in Culture and Downregulation of Trophoblast Endothelial Protein C Receptor by TNF-α

In mice, trophoblasts are equipped with a potent anticoagulant mechanism, the protein C pathway. In human placenta, no functional studies of the protein C pathway are available. Human first-trimester trophoblasts (CK(++) HLA-G(+/-) Vim(-)) were isolated and kept in culture for a maximum of 48 hours. Activation of protein C on trophoblasts was at least as efficient as in endothelial cells (4.43 × 10 (-) (7) nmol/L/min/cell). Endothelial protein C receptor (EPCR) was expressed in syncytiotrophoblasts and extravillous trophoblasts. Downregulation of the messenger RNA of trophoblast EPCR occurred when trophoblasts were challenged with tumor necrosis factor α, and it could be prevented by unfractionated heparin but not by low-molecular-weight heparin at therapeutic doses. In conclusion, there is a functional protein C pathway on human first-trimester trophoblasts which can be modulated by inflammation. This finding has implications for the pathogenesis and prevention of placenta-mediated obstetric complications.

Tumour-associated fibroblasts contribute to neoangiogenesis in human parathyroid neoplasia

Components of the tumour microenvironment initiate and promote cancer development. In this study, we investigated the stromal component of parathyroid neoplasia. Immunohistochemistry for alpha-smooth muscle actin (α-SMA) showed an abundant periacinar distribution of α-SMA(+) cells in normal parathyroid glands (n=3). This pattern was progressively lost in parathyroid adenomas (PAds; n=6) where α-SMA(+)cells were found to surround new microvessels, as observed in foetal parathyroid glands (n=2). Moreover, in atypical adenomas (n=5) and carcinomas (n=4), α-SMA(+) cells disappeared from the parenchyma and accumulated in the capsula and fibrous bands. At variance with normal glands, parathyroid tumours (n=37) expressed high levels of fibroblast-activation protein (FAP) transcripts, a marker of tumour-associated fibroblasts. We analysed the ability of PAd-derived cells to activate fibroblasts using human bone-marrow mesenchymal stem cells (hBM-MSCs). PAd-derived cells induced a significant increase in FAP and vascular endothelial growth factor A (VEGFA) mRNA levels in co-cultured hBM-MSCs. Furthermore, the role of the calcium-sensing receptor (CASR) and of the CXCL12/CXCR4 pathway in the PAd-induced activation of hBM-MSCs was investigated. Treatment of co-cultures of hBM-MSCs and PAd-derived cells with the CXCR4 inhibitor AMD3100 reduced the stimulated VEGFA levels, while CASR activation by the R568 agonist was ineffective. PAd-derived cells co-expressing parathyroid hormone (PTH)/CXCR4 and PTH/CXCL12 were identified by FACS, suggesting a paracrine/autocrine signalling. Finally, CXCR4 blockade by AMD3100 reduced PTH gene expression levels in PAd-derived cells. In conclusion, i) PAd-derived cells activated cells of mesenchymal origin; ii) PAd-associated fibroblasts were involved in tumuor neoangiogenesis and iii) CXCL12/CXCR4 pathway was expressed and active in PAd cells, likely contributing to parathyroid tumour neoangiogenesis and PTH synthesis modulation.

Stillbirth and fetal growth restriction

OBJECTIVE

To confirm the role of fetal growth restriction (FGR) as a cause of stillbirth, and to compare diagnostic accuracy of customized fetal growth and population-based standards in identifying FGR within a pathological population of early and late stillbirths.

METHODS

Retrospective study on a cohort of 189 stillbirths occurred in single pregnancy between January 2006 and September 2011. Unexplained stillbirths, defined by Aberdeen-Wigglesworth and ReCoDe classifications, were evaluated on the basis of fetal birthweight with both Tuscany population and Gardosi customized standards. Unexplained stillbirths have been classified as early or late depending on the gestational age of occurrence.

RESULTS

Aberdeen-Wigglesworth classification, applied to the 189 cases of stillbirth, left 94 unexplained cases (49.7%), whereas the ReCoDe classification left only 40 (21%). By applying population standards to the 94 unexplained stillbirths we have identified 31 FGRs (33% of sample), while customized standards identified 54 FGRs (57%). Customised standards identified a larger number of FGRs with respect to population standards during the third trimester (i.e. 51% vs. 25% respectively) than in the second trimester (73% vs. 54% respectively) (p = 0.05).

CONCLUSIONS

Customized standards have a higher diagnostic accuracy in identifying FGRs especially during the third trimester.

Is HCMV a tumor promoter?

Human cytomegalovirus (HCMV) is a beta-herpesvirus that causes persistent infection in humans and can cause severe disease in fetuses and immunocompromised individuals. Although HCMV is not currently causally implicated in human cancer, emerging evidence suggests that HCMV infection and expression may be specifically associated with human malignancies including malignant glioma, colon, and prostate cancer. In addition, multiple investigators have demonstrated that HCMV can dysregulate signaling pathways involved in initiation and promotion of malignancy, including tumor suppressor, mitogenic signaling, inflammatory, immune regulation, angiogenesis and invasion, and epigenetic mechanisms. This review highlights some of the recent evidence that HCMV might play a role in modulating the tumor microenvironment as well as in the initiation and promotion of tumor cells themselves.

Effects of gestational diabetes on fetal oxygen and glucose levels in vivo

OBJECTIVE

Fetal hypoxia and acidemia have been reported in pregestational diabetic pregnancies in relation to poor glycaemic control, but it is still uncertain whether this is the case in apparently well-controlled gestational diabetes.

POPULATION AND METHODS

Maternal arterial and umbilical venous and arterial blood samples were collected from 37 normal (N) and 38 pregnancies complicated by gestational diabetes (GDM) at the time of caesarean section.

MAIN OUTCOME MEASURES

Respiratory gases, acid-base balance, lactate and glucose concentrations were measured.

RESULTS

Both fetal and placental weights were significantly increased in GDM compared to N pregnancies, despite similar gestational age. Maternal biochemical parameters were similar in N and GDM but GDM fetuses were significantly more hypoxic (O2 saturation: N 63.2+/-13.9; GDM 53.8+/-14.6%, P<0.01; O2 content: N 5.5+/-1.4; GDM 4.8+/-1.2 mmol/l, P<0.05). Glucose (N 3.4+/-0.5, GDM 3.9+/-1.2 mmol/l, P<0.05) and lactate (N 1.32+/-0.49; GDM 1.64+/-0.75 mmol/l, P<0.05) concentrations were significantly increased in the umbilical vein in GDM compared to N fetuses. Placental histology was consistent with altered villous morphology.

CONCLUSIONS

Our data indicate that fetuses from gestational diabetic mothers have increased umbilical glucose concentrations despite normal maternal glucose levels and a reduction in oxygen saturation and O2 content together with increased lactate concentration, reflecting altered fetal metabolism. These data suggest that 'good maternal metabolic control' achieved by currently used methods of monitoring glucose control is not sufficient to ensure a normal oxygenation status and metabolic milieu for the fetus in GDM pregnancies.

Congenital heart disease: a retrospective study of their frequency

AIM

An early diagnosis of congenital heart disease (CHD) is necessary for the obstetrical management.

METHODS

One thousand five hundred and fifty-six pregnant women underwent a fetal 2-D echocardiography from 1991 to 2002. We assessed patients who had the most common risk factor (RF): family history of CHD, diabetes mellitus, teratogen drugs, polyhydramnios, abnormal fetal growth, fetal arrhythmia, maternal age over 40 years, maternal autoimmune disease, maternal disease contracted during pregnancy, oligohydramnios, only umbilical artery, uncorrected visualization in the first level 2-D fetal echocardiography.

RESULTS

In 110 morphological anomalies found 54 were complex. The malformations are not equally distributed among the different RF. The most common RF is the family history of CHD where 24 patients showed complex malformations. Another high percentage of complex malformations was found in patients with no apparent presence of RF: the diagnosis was done after an uncorrected cardiac visualization in the first level 2-D echocardiography. In the minor cardiomyopathies we did not find the prevalence of any RF. After diagnosis of complex malformations we had 15% of termination of pregnancies, 37% of the newborns are alive and in good health.

CONCLUSIONS

The first RF is the family history of CHD, but a correct first level fetal 2-D echocardiography is necessary because a very high percentage of complex malformations is seen in infant whose mother did not have any RF. Ninety percent of cardiac malformations where seen in a 4 chamber view, and it is of the utmost importance also for a correct diagnosis of minor cardiomyopathies where we did not find a predominant RF.