Abnormal placental villous maturity and dysregulated glucose metabolism: implications for stillbirth prevention

OBJECTIVES

In the UK one in 250 pregnancies end in stillbirth. Abnormal placental villous maturation, commonly associated with gestational diabetes, is a risk factor for stillbirth. Histopathology reports of placental distal villous immaturity (DVI) are reported disproportionately in placentas from otherwise unexplained stillbirths in women without formal diagnosis of diabetes but with either clinical characteristics or risk factors for diabetes. This study aims to establish maternal factors associated with DVI in relation to stillbirth.

METHODS

Placental histopathology reports were reviewed for all pregnant women delivering at University College London Hospital between July 2018 to March 2020. Maternal characteristics and birth outcomes of those with DVI were compared to those with other placental lesions or abnormal villous maturation.

RESULTS

Of the 752 placental histopathology reports reviewed, 11 (1.5%) were reported as diagnostic of DVI. Eighty cases were sampled for clinical record analysis. All women with DVI had normal PAPP-A (>0.4 MoM), normal uterine artery Doppler studies (UtA-PI) and were normotensive throughout pregnancy. Nearly one in five babies (2/11, 18.5%) with DVI were stillborn and 70% had at least one high glucose test result in pregnancy despite no formal diagnosis of diabetes.

CONCLUSIONS

These findings suggest that the mechanism underlying stillbirth in DVI likely relates to glucose dysmetabolism, not sufficient for diagnosis using current criteria for gestational diabetes, resulting in placental dysfunction that is not identifiable before the third trimester. Relying on conventional diabetes tests, foetal macrosomia or growth restriction, may not identify all pregnancies at risk of adverse outcomes from glucose dysmetabolism.

Accuracy of antenatal fetal ultrasound in the diagnosis of duplex kidneys

OBJECTIVES

To assess the accuracy of ultrasound diagnosis of duplex kidneys in the fetus and to identify prognostic features of antenatal sonography associated with this diagnosis.

METHODS

Retrospective identification of cases with an antenatal diagnosis of duplex kidney was made from computerized databases. Results of postnatal radiological investigations were obtained from the unit where delivery took place.

RESULTS

A total of 75% of cases seen in a multidisciplinary fetal renal clinic were correctly diagnosed as having a duplex kidney. Prognostic sonographic features are described. Detection of two separate poles or a ureterocele were strongly associated with a correct diagnosis. Accuracy was increased when two or more prognostic features were seen.

CONCLUSION

Accurate sonographic diagnosis of duplex kidneys in the fetus is possible in a dedicated multidisciplinary setting. Antenatal counseling and planning of postnatal care for the infant can be made with a high degree of certainty.

Duplex systems

Duplex kidneys occur in 0.8% of the general population, many of whom are asymptomatic. Children with duplex kidneys may be prone to urinary tract infections because of vesico-ureteric reflux or obstruction. Surgical management is usually required once symptoms occur. Increasing numbers of duplex kidneys are now prenatally diagnosed by ultrasound, resulting in the development of early postnatal strategies to try and reduce morbidity.