HELLP syndrome preceded by intrahepatic cholestasis of pregnancy: one serious itch

The association of serum total bile acid with new-onset hypertension during pregnancy

Background

There has been considerable interest in the interrelationship between the liver and hypertension. The relationship between serum total bile acid (TBA) and hypertension has been reported. Moreover, intrahepatic cholestasis of pregnancy was correlated to gestation hypertension. However, the association between maternal serum TBA level in the normal range and new-onset hypertension disorders during pregnancy remains unclear. The present study aimed to evaluate the relationship between maternal serum TBA level in the normal range and the risk, disease severity and adverse pregnancy outcomes of new-onset hypertension during pregnancy.

Method

Using the electronic medical records on all pregnant women from the Department of Obstetrics and Gynecology, Third Affiliated Hospital of Guangzhou Medical University, between 2014 and 2020, we conducted a retrospective cohort study of 2581 singleton pregnant women with maternal serum TBA levels in the normal range. Patients were grouped into the non-hypertension during pregnancy (1071), gestational hypertension (480) and preeclampsia (1030) groups.

Result

We found that maternal serum TBA levels were significantly higher in the preeclampsia and gestational hypertension groups than in the non-hypertension group (p < 0.01). Multiple logistic regression analysis showed that TBA level was independently and significantly associated with preeclampsia and gestational hypertension (odds ratio: 1.37, 95% confidence interval [CI]: 1.27–1.48, p = 0.001, odds ratio: 1.34, 95% confidence interval [CI]: 1.24–1.46, p = 0.005, respectively). Moreover, elevated TBA level was positively associated with the risk of severe PE and negatively with mild PE (p < 0.01). In addition, maternal serum TBA levels were negatively related to birth weight (p < 0.001).

Conclusions

These results suggest that maternal serum TBA in the normal range also might be a valuable biomarker for disease severity in preeclampsia and gestational hypertension. Additionally, our results also indicate associations of serum total bile acid levels in the normal range with an increased risk of fetal growth restriction and low birth weight among offspring. These results suggest that TBA could serve as a prognostic biomarker for new-onset hypertension during pregnancy.

Severe intrahepatic cholestasis of pregnancy is a risk factor for preeclampsia in singleton and twin pregnancies

OBJECTIVE

Intrahepatic cholestasis of pregnancy (ICP) is known to be associated with fetal complications. It recently was suggested to be associated possibly with preeclampsia (PET) as well. The objective of this study was to investigate that possibility.

STUDY DESIGN

The study group included 78 women (54 singleton and 24 twin pregnancies) who had been diagnosed with ICP based on clinical presentation, elevated liver enzymes, and elevated total bile acids (>10 μmol/L). Disease severity was based on total bile acids levels as being severe (>40 μmol/L), moderate (20-40 μmol/L), or mild (10-20 μmol/L). The course of disease was reviewed carefully in each case. The control groups were comprised of apparently healthy women with singleton (n = 200) and twin (n = 100) pregnancies that were drawn randomly from a computerized registry of all the deliveries in our institution during the study period.

RESULTS

The total incidence of PET was significantly higher for the patients with ICP who had singleton and twin pregnancies compared with the control groups (singletons: 7.4% vs 1.5%; P < .05; twins: 33.3% vs 6.2%; P < .05, respectively). The incidence of severe PET was also significantly higher in both singleton (11-fold) and twin (8-fold) pregnancies compared with control subjects. Severe ICP, but not mild ICP, was a major risk factor for PET among women with either singleton or twin pregnancies. The timing of the initial presentation of ICP had no effect on PET incidence rates. Preeclampsia occurred usually 2-4 weeks after the diagnosis of ICP, and proteinuria preceded elevated blood pressure in all cases. Moreover, the total bile acid levels among 33 women who were diagnosed as having PET, but not ICP, were within normal range.

CONCLUSION

ICP increases the incidence of PET; severe disease was a major risk factor for preeclampsia. Therefore, we strongly suggest including routine evaluation for preeclampsia in the treatment of women with moderate and severe ICP.

Total bile acids in the maternal and fetal compartment in relation to placental ABCG2 expression in preeclamptic pregnancies complicated by HELLP syndrome

OBJECTIVE

To investigate total bile acid (TBA) levels in maternal (MB) and umbilical cord blood (UCB) in normotensive, preeclamptic (PE), and PE pregnancies complicated by hemolysis elevated liver enzymes and low platelets (HELLP) syndrome in the context of ABCG2 placental gene expression levels, a recently reported placental bile acid transporter.

METHODS

TBA levels were determined in 83 paired MB and UCB samples of normotensive, PE and PE/HELLP pregnancies and in 22 paired arterial and venous UCB samples from uncomplicated term pregnancies. ABCG2 gene expression was measured in 104 human placentas by reverse transcriptase quantitative polymerase chain reaction.

RESULTS

Overall, TBA levels in MB are higher compared to levels in UCB (p<0.0001), but this comparison looses statistical significance for the 11 PE/HELLP cases. TBA levels in maternal blood are increased in PE/HELLP compared to PE pregnancies (p=0.016). TBA levels in arterial and venous UCB from 22 normotensive pregnancies are not statistically different. ABCG2 expression is reduced in pregnancies where preeclampsia is further complicated by HELLP syndrome. ABCG2 expression in human placenta is not correlated with TBA levels in either the maternal or fetal compartment.

CONCLUSION

Increased maternal TBA levels in PE/HELLP pregnancies indicate a relation between bile acids in the maternal circulation and HELLP syndrome. As overall TBA levels in maternal blood are increased compared to UCB, we conclude that the placenta partly protects the fetus from increased maternal TBA levels. This consistent difference in TBA levels between the maternal and fetal compartment is unrelated to the placental expression of ABCG2.