Shanghai cohort of 48,032 pregnancies: elevated early liver enzymes linked to higher preterm birth odds
In a retrospective study at a Shanghai hospital, raised ALT, AST and especially GGT at the first antenatal visit were associated with preterm birth, mainly iatrogenic. Prospective studies are still needed.
A retrospective cohort study from a tertiary care hospital in Shanghai, China, examined liver function tests taken in early pregnancy and their relationship to preterm birth (PTB). According to the paper published via doi.org, 57,386 singleton pregnancies were screened and 48,032 women were included in the final analysis biomedcentral.com
doi.orgbiomedcentral.comOpen source ↗. All of them had liver tests at the first antenatal visit, between 6 and 19 weeks plus 6 days of gestation.
The authors measured ALT, AST, GGT, total bilirubin (TBiL) and direct bilirubin (DBiL). Binary logistic regression estimated the odds of any PTB versus term birth. Multinomial logistic regression, with term birth as the reference, was used jointly for spontaneous and iatrogenic PTB, with adjustment for key covariates.
ALT and AST
Elevated ALT and AST (above 80 U/L) were associated with higher odds of iatrogenic PTB. No significant associations were found for spontaneous PTB.
Compared with the reference ALT group of 0–40 U/L, ALT of 81–200 U/L was associated with 42.3% higher adjusted odds of iatrogenic PTB (aOR 1.423, 95% CI 1.021–1.983). ALT above 200 U/L was associated with higher odds of total PTB (aOR 1.287, 95% CI 1.008–1.645) and 3.28-fold higher adjusted odds of iatrogenic PTB (aOR 3.282, 95% CI 1.315–8.194) biomedcentral.com
doi.orgbiomedcentral.comOpen source ↗.
Moderately elevated AST (81–200 U/L) corresponded to 2.00-fold higher adjusted odds of iatrogenic PTB (aOR 1.998, 95% CI 1.088–3.671).
GGT and combined elevations
For GGT, every subgroup above the 0–12 U/L reference showed significantly higher odds for both spontaneous and iatrogenic PTB. The magnitude of the association rose gradually with GGT concentration.
The authors built four-level stratified variables combining ALT or AST with GGT. No statistically significant multiplicative interaction between ALT/AST elevation and GGT elevation was detected for any PTB subtype biomedcentral.com
doi.orgbiomedcentral.comOpen source ↗.
In the ALT–GGT stratification, isolated GGT elevation and concurrent ALT and GGT elevation were significantly associated with higher risk of iatrogenic PTB, while isolated ALT elevation was not. In the AST–GGT stratification, isolated GGT elevation and concurrent AST and GGT elevation were associated with higher odds of iatrogenic PTB. Isolated AST elevation was not significantly related to any PTB subtype.
The authors concluded that elevated early-pregnancy liver biomarkers, particularly GGT, were associated with subsequent PTB risk. They noted that prospective studies are needed to determine whether these biomarkers improve risk stratification.
