Bile acids in a multicenter, population-based case-control study of stillbirth

DLK1: A Novel Biomarker of Placental Insufficiency in Stillbirth and Live Birth

OBJECTIVE

 Delta-like homolog 1 (DLK1) is a growth factor that is reduced in maternal sera in pregnancies with small for gestational age neonates. We sought to determine if DLK1 is associated with stillbirth (SB), with and without placental insufficiency.

STUDY DESIGN

 A nested case-control study was performed using maternal sera from a multicenter case-control study of SB and live birth (LB). SB and LB were stratified as placental insufficiency cases (small for gestational age <5% or circulatory lesions on placental histopathology) or normal placenta controls (appropriate for gestational age and no circulatory lesions). Enzyme-linked immunosorbent assay (ELISA) was used to measure DLK1. The mean difference in DLK1 was compared on the log scale in an adjusted linear regression model with pairwise differences, stratified by term/preterm deliveries among DLK1 results in the quantifiable range. In exploratory analysis, geometric means were compared among all data and the proportion of "low DLK1" (less than the median value for gestational age) was compared between groups and modeled using linear and logistic regression, respectively.

RESULTS

 Overall, 234 SB and 234 LB were analyzed; 246 DLK1 values were quantifiable within the standard curve. Pairwise comparisons of case and control DLK1 geometric means showed no significant differences between groups. In exploratory analysis of all data, adjusted analysis revealed a significant difference for the LB comparison only (SB: 71.9 vs. 99.1 pg/mL, p = 0.097; LB: 37.6 vs. 98.1 pg/mL, p = 0.005). In exploratory analysis of "low DLK1," there was a significant difference between the odds ratio of having "low DLK1" between preterm cases and controls for both SB and LB. There were no significant differences in geometric means nor "low DLK1" between SB and LB.

CONCLUSION

 In exploratory analysis, more placental insufficiency cases in preterm SB and LB had "low DLK1." However, low DLK1 levels were not associated with SB.

KEY POINTS

· Maternally circulating DLK1 is correlated with placental insufficiency.. · Maternally circulating DLK1 is not correlated with SB.. · DLK1 is a promising marker for placental insufficiency..

Stillbirth risk factors, causes and evaluation

Stillbirth impacts 5.73 per 1,000 births in the United States and this rate exceeds that of contemporary high-resource countries.1,2 Risk factors include both demographic and medical characteristics. There are also numerous pathophysiologic mechanisms that can lead to stillbirth. Unfortunately, these risk factors are fairly common, making stillbirth risk stratification and prevention challenging. This is due in part to a large number of unexplained stillbirths. In a large, multi-center study of stillbirths, approximately 24% of stillbirths remained unexplained following thorough, standardized evaluation.3 The number of unexplained stillbirths is unquestionably larger outside of a rigorous study protocol, but real-world data are lacking. This large proportion of unexplained stillbirth cases makes achieving further decreases in the stillbirth rate difficult given lack of understanding of underlying causes in this population. Cause of death identification can be improved with adoption of an evidence-based, comprehensive stillbirth evaluation.

Role of ursodeoxycholic acid on maternal serum bile acids and perinatal outcomes in intrahepatic cholestasis of pregnancy

AIM

Intrahepatic cholestasis of pregnancy (ICP) is associated with safe maternal outcomes but perinatal outcomes have been variable. We assessed clinical factors and impact of bile acid levels on maternal and neonatal outcomes in ICP.

METHODS

Patients with ICP (defined as pruritus with serum bile acids ≥ 10 mmol/l) were included prospectively with an assessment of risk factors, modes of delivery as well as maternal and neonatal outcomes. Mild and severe ICP were diagnosed when serum bile acid was always <40 mmol/l and ≥40 mmol/l, respectively. Patients with gestational pruritus served as controls.

RESULTS

Out of 643 patients, 375 patients (mean age 29 ± 7.6 years, 45.8% primigravida) met inclusion criteria. Pregnancy-induced hypertension [PIH: 10.5%; odds ratio (OR): 4.8; 95% confidence interval (CI): 2.4-8.5; P = 0.0014], gestational diabetes (GDM: 12.5%; OR: 2.6; 95% CI: 2.3-4.1; P = 0.045) and spontaneous preterm labor (15.1%; OR: 2.5; 95% CI: 1.2-3.5; P = 0.040) were higher in patients with ICP. Ursodeoxycholic acid (UDCA) (median dose 900 mg; 600-1800 mg) ameliorated symptoms of cholestasis, bile acid levels and liver aminotransferases in 79% cases. When compared with patients with mild ICP, patients with severe ICP presented at a lower gestational period (26 vs. 32 weeks, P = 0.036), required frequent induction (12.5%; OR: 3.2; 95% CI: 2.1-5.6; P = 0.045) and had increased fetal distress (15%; OR: 1.9; 95% CI: 1.3-4.9; P = 0.048).Overall eight stillbirths were recorded.

CONCLUSION

Severe ICP is associated with a higher incidence of GDM and PIH, risk of pre-term labor, elective induction and stillbirths. UDCA remains a first-line agent in treating ICP.

Stillbirth: Evaluation and Follow-up

A systematic, effective stillbirth evaluation is important for identification of potential causes of fetal death. Knowledge of potential causes of fetal death facilitates emotional closure for patients and informs recurrence risk as well as future pregnancy management. The highest-yield components of a stillbirth evaluation for finding a cause of fetal death are fetal autopsy, placental pathology, and genetic testing. All patients should be offered these tests following a stillbirth. A clear plan for postpartum follow-up should be made with the patient in order to ensure ongoing support through the grief and recovery process.

Sensitivity and Specificity of Biochemical Tests for Diagnosis of Intrahepatic Cholestasis of Pregnancy

BACKGROUND AND AIM

Intrahepatic cholestasis of pregnancy (ICP) is linked with increased risk of fetal complications. An accurate diagnostic test is needed to diagnose this disorder on time. We aimed to assess sensitivity and specificity of laboratory tests used for diagnosis of intrahepatic cholestasis of pregnancy and determine more reliable cut-off values of transaminases.

MATERIAL AND METHODS

Sixty one symptomatic patients with ICP and 29 healthy pregnant women were included in the retrospective analysis.

RESULTS

ICP patients had higher total bile acids (TBA) levels than healthy women (32 vs. 6; P < 0.0001) due to increase in cholic acid (CA) and chenodeoxycholic acid (CDCA). CA/CDCA ratio was significantly higher in ICP patients compared to healthy pregnant women (1.13 vs. 0.68; P < 0.00002). TBA, CA, CDCA and CA/CDCA ratio demonstrate the following sensitivity (94%, 96%, 89%, 71.9%) and specificity (63%, 63%, 59%, 79.3%, respectively) for ICP diagnosis. Lowering cut-off values for ALT (31 U/L) and AST (30 U/L) resulted only in minimal increase of sensitivity to 92.2% vs. 90.1% for ALT and to 92.2%, vs. 90.6% for AST.

CONCLUSION

The present study did not reveal any single specific and sensitive marker for reliable diagnosis of ICP. Establishment of lower cut-off values for transaminases activity might only minimally increase the accuracy of diagnosing ICP.

Perinatal death investigations: What is current practice?

Perinatal death (PD) is a devastating obstetric complication. Determination of cause of death helps in understanding why and how it occurs, and it is an indispensable aid to parents wanting to understand why their baby died and to determine the recurrence risk and management in subsequent pregnancy. Consequently, a perinatal death requires adequate diagnostic investigation. An important first step in the analysis of PD is to identify the case circumstances, including relevant details regarding maternal history, obstetric history and current pregnancy (complications are evaluated and recorded). In the next step, placental examination is suggested in all cases, together with molecular cytogenetic evaluation and fetal autopsy. Investigation for fetal-maternal hemorrhage by Kleihauer is also recommended as standard. In cases where parents do not consent to autopsy, alternative approaches such as minimally invasive postmortem examination, postmortem magnetic resonance imaging, and fetal photographs are good alternatives. After all investigations have been performed it is important to combine findings from the clinical review and investigations together, to identify the most probable cause of death and counsel the parents regarding their loss.