General feature of APIP patients with organ failure
In this group of APIP with OF patients, their age range was 19–45 years. The disease onset range was 11–40 gestational weeks, with 2 patients in the first trimester (before 14 weeks), 20 in the second trimester (14-27+6 weeks), and 109 in the third trimester (after 28 weeks). The etiology of APIP patients with OF was HTG in 76 patients (58.0%), biliary in 20 (15.3%), and idiopathic in 35 (26.7%).
96 patients (72.3%) presented with upper abdominal pain and 51 (38.9%) were presented with nausea and vomiting. 18 patients (13.7%) exhibited overeating before disease onset. 39 patients (29.8%) sought medical help within 12 h of symptom onset, while 58 (44.2%) sought medical help within 12–24 h. The mean length of hospitalization was 19.45±14.53 days (2–117 days) and 124 patients (94.5%) received intensive care.
General condition between TOF and POF groups
All the enrolled patients were categorized into TOF and POF groups and the generalcondition was compared between the two groups. The average age of thePOFgroup was older than that of the TOF group(P=0.015). There were significant differences in the distribution of trimesters of pregnancybetween POF and TOF groups(P=0.040). The etiological composition of the two groups was significantly different (P= 0.045 ). The ratio of biliary in TOF group was higher than that of the POF group (17.9% VS 10.6%),while the POF group has more HTGP than the TOF group (72.3% VS 50%).
There were no significant differences in body mass index (BMI), gravidity, parity, initial symptoms, and history of diabetes and hypertension between the two groups of patients (Table.1).
Clinical course of APIP patient with TOF and POF
All patients developed OF within 1 week of onset. Respiratory failure is the commonest OF. There was no significant difference in the incidence of renal failure between the two groups.The incidence of respiratory failure and circulatory failure was significantly higher in the POF group than that in the TOF group (P=0.006 and P=0.001, respectively). Higher total hospital costs, longer hospital andintensive care unit (ICU) staywere noted among the patients inthe POFgroup compared to the patients in the TOP group (P<0.05).
Detailed analyses revealed that the incidences of hyperglycemia (P=0.013), hypocalcemia (P=0.002), and DKA (P=0.001) were significantly higher inthe POF group. Although the incidence of pleural (P=0.003) and peritoneal effusions(P=0.012)were also significantly higher in the POF group, the incidence ofpelvic effusion was not (Table. 2 ).
Maternal and pregnancy outcomes
All 131 patients delivered during hospitalization. Gestation was terminated by different approaches, mainly based on fetal and maternal conditions, with cesarean section being the main mode of deliveryin the two groups (Table. 2 ).
7 maternal deaths were observed in the present study, they were all with HTG as etiology and from thePOF group(14.9%, P<0.05, Table. 2 ). 3 died from multiple organ dysfunctions (at gestational week 34, 23, and 34, respectively), 2 from cardiac sudden death (at gestational week 32 and 33), 1 fromhypoxic encephalopathy(at gestational week 25) and 1 fromhemorrhagic shock (at gestational week 30). Seven maternal deaths were all happenedduring the hospitalization.
The perinatal loss rate was 61.7% in the POF group which was significantly higher than that in the TOF group ( 22.6%, P<0.05, Table. 2).
Perinatal outcomes
83 (63.3%) neonates were born alive in the present study. None of the fetusesof those mothers with disease onset in the first and second trimesters survived. Table.3 showed the neonatal characteristics. The gestational age was significantly younger in the POF group than that in the TOF group. There were no significant differences between the POF and TOF groups in the remaining neonatal characteristics.
Independent risk factors for POF development in APIP patients
To explore the laboratory parameters that can predict POF, the laboratory test indexes of the two group patients within 24h of admission were compared. The concentrations of triglycerides (TG), cholesterol, fast blood glucose, serum calcium, C reactive protein (CRP), aspartate aminotransferase (AST), serum creatinine(SCr), blood urea nitrogen (BUN), lactate dehydrogenase (LDH), and procalcitonin (PCT) in the POF groupwere significantly different from those in TOF group (P<0.05, Table.4).
Clinical indicators with statistical differences(P<0.05) were included in the univariate analysis based on the results in Tables 1 and 4. The concentrations ofTG, cholesterol, fast blood glucose,SCr, LDH, PCT, and trimesterofpregnancywere significantly associated with POF in univariate analysis (Table 5). We performed multivariate logistic regression analysis with these associated factors using a stepwise method. TG,SCr, LDH, and PCTwere identified as independent risk factors (Table 5).
Nomogram model for POF
The POF predicting nomogram was constructed based on 4 independent predictors (Fig. 2). By drawing a line from each predictor straight upwards the point axis, we could get every point for each variable. By summing up each point, the total points can be calculated. By drawing a line from the total point axis straight down, the incidence of POF could be estimated. The nomogram could be applied to estimate the incidenceof POF for each patient in clinical practice.
The area under the curve (AUC) was 0.875 (95% confidence interval (CI) 0.80–0.95; Fig. 3) and the concordance index (C-index) of the nomogram was 0.85 (95% CI, 0.77-0.93; Fig. 4), indicating that the nomogram was accurate in estimating the risk of POF. The calibration of the model was also assessed with calibration curves.Figure 4 shows that predictions made by the model were close to the observed outcomes, which furtherdemonstrates the reliability of the nomogram in POF risk estimation.