Maternal liver damage markers can predict twin pregnancy outcomes
Study: ICP diagnosis before 32 weeks of gestation found to be a risk factor
High maternal levels of liver damage markers in the blood can predict poor fetal outcomes in twin pregnancies affected by intrahepatic cholestasis of pregnancy (ICP), a study reported.
Being diagnosed with ICP before 32 weeks of gestation was also found to be an independent risk factor for poor neonatal outcomes in twin pregnancies.
Risk factors differed partly between monochorionic (MC) pregnancies, or those where twins share a placenta, and dichorionic (DC) pregnancies, where each twin has their own placenta.
“Greater emphasis should be [placed on] monitoring of predelivery liver functional biochemical indexes in pregnant women according to chorionicity [number of placentas] complicated by ICP, to facilitate personalized antenatal management and improve neonatal outcomes,” the researchers wrote.
The study, “A retrospective cohort study on perinatal outcomes of monochorionic and dichorionic twin pregnancies complicated by intrahepatic cholestasis of pregnancy,” was published in Scientific Reports.
No study had compared outcomes between MC, DC groups
In cholestasis, the flow of the digestive fluid bile from the liver to the intestines becomes slowed or stalled. This may lead to liver damage and bile leakage into the bloodstream, causing symptoms like itchiness, fatigue, and jaundice, or yellowing of the skin and eyes.
ICP is the most common liver disease related to pregnancy and can pose risks to both the mother and the baby. Approximately 20% to 25% of twin pregnancies are impacted by ICP, and “it has been reported that … outcomes associated with ICP in twin pregnancies were worse than those in singleton pregnancies,” the researchers wrote.
There has been some research on outcomes of MC and DC twin pregnancies affected by ICP, but no study to date has compared outcomes between these two groups.
With this in mind, a team of researchers in China retrospectively reviewed records of 93 MC and 270 DC twin pregnancies affected by ICP that were followed at a single Chinese hospital.
Women in the DC group were significantly older (mean of 30.74 vs. 29.80 years) and more likely to have used in vitro fertilization to conceive (64.07% vs. 36.56%).
Preterm birth more common in MC group
During pregnancy, maternal levels of several markers of liver function in the blood differed between the two groups. Women in the DC group had significantly higher rates of abnormally low blood levels of proteins (39.26% vs. 27.96%) and infection of the female reproductive system (26.30% vs. 13.98%).
Preterm birth (before 37 weeks of gestation) was significantly more common in the MC group than in the DC group (95.70% vs. 65.56%).
Twin babies from MC pregnancies had a significantly lower birth weight, and were significantly more likely, by about two to five times, to develop pneumonia (a lung infection that inflames the air sacs) and bleeding of the lower gastrointestinal tract.
The rates of jaundice and low potassium were about two to five times higher among babies from DC pregnancies.
Although the mechanism is unclear, DC twin pregnancies with elevated AST and TBIL require intensified surveillance and management based on our results.
Further statistical analyses identified factors that predicted poor fetal outcomes. In both groups, having an ICP diagnosis before 32 weeks of gestation was significantly associated with an increased risk of poor outcomes.
In women in the MC group, high blood levels of bile acids, the main components of bile, were significantly linked to a five times higher risk of poor neonatal outcomes. In the DC group, high maternal blood levels of aspartate transaminase (AST) and total bilirubin (TBIL), two liver damage markers, were each significantly linked to a greater risk of poor outcomes.
“Although the mechanism is unclear, DC twin pregnancies with elevated AST and TBIL require intensified surveillance and management based on our results,” the researchers wrote.
Close monitoring recommended in cases of twin pregnancy
Statistical analyses adjusted for potential influencing factors showed that early ICP diagnosis remained an independent risk factor. It was linked to a nearly 10% higher risk in the MC group and a more than 13 times higher risk in the DC group. The only other independent risk factor was high AST levels in the DC group.
The findings generally suggest close monitoring during ICP twin pregnancies is advisable. The team recommended considering early termination of the pregnancy in severe cases and timing delivery to mitigate risks.
In ICP, “the timing of delivery should be decided on an individual basis according to the perinatal risk and benefits of available management options,” the researchers wrote.
Overall, “more focus should be paid to monitoring predelivery liver function biochemical indexes in pregnant women with [MC and DC] twins, which might facilitate personalized [predelivery] management to improve neonatal outcomes,” the team wrote.
Further research, including studies monitoring maternal and fetal health throughout pregnancy, could help to better understand risk factors.
