In this study, women with early-onset preeclampsia with severe features had favorable outcomes. High maternal serum creatinine was associated with adverse maternal outcomes, while delivery before 32 weeks of gestation, maternal diabetes mellitus, high serum creatinine and elevated serum aminotransferases increased the risk of adverse perinatal outcomes.
Similar to other studies, there was very low rate of maternal death among women with early-onset preeclampsia with severe features [13–18]. The incidence of HELLP syndrome was similar to that in a previous report in Thailand, about 28% , but was more than those reported in other countries, which ranged from 12–15% [14–17], which might be explained by the differences in gene expression in placenta, concentrations of anti-angiogenic factors or degrees of inflammatory responses in different ethnicities . The rates of abruptio placentae and eclampsia reported in our study were low. Since two out of three women with abruptio placentae during expectant management had uncontrolled blood pressure, and all had non-reassuring fetal heart monitoring, we suggest that physicians should emphasize on blood pressure control and close observation of fetal health status. Poorly controlled blood pressure needs expedited delivery. In regard to perinatal outcomes, the perinatal mortalities were not different among various parts of the world [13–17].
We found that high maternal serum creatinine was the only factor associated with adverse maternal outcomes. It is understandable as kidney is one of the most frequently affected organs from inflammatory response and/or vasoconstriction in preeclampsia [6, 20]. Once kidney dysfunction is evident, it indicates that other organs might be deteriorated. It is generally accepted that preterm delivery and maternal diabetes mellitus are related to adverse neonatal outcomes [10, 21]. They were also associated with poor perinatal outcomes in our study. Apart from gestational age at delivery and maternal diabetes mellitus, we found that high maternal serum creatinine and elevated serum aminotransferases, which reflect the severity of preeclampsia, were also associated with serious adverse neonatal outcomes. Ganzevoort et al. reported that early gestational age at admission was the only significant factor influencing adverse neonatal outcomes. However, they did not evaluate the associations between maternal diabetes mellitus or maternal serum creatinine level and adverse outcomes .
The strengths of this study were; 1) large sample size; 2) complete and reliable database; 3) diagnoses and managements adherent to ACOG guidelines; and 4) determination of factors associated with adverse maternal and perinatal outcomes.
The limitation of our study was that it was a retrospective study. There were a few incomplete data such as laboratory results from referring hospitals, and patient histories and physical examination findings depended on the level of completion of medical records at the time of diagnosis. As aspirin prescription was just recently added to the preeclampsia prevention guideline in 2016 , there was only a small percentage (6.7%) of aspirin prescription in our data. Because of this small percentage, the effects of aspirin prescription on the severity of preeclampsia might not be apparent.
According to the favorable outcomes of the management of early-onset preeclampsia with severe features in our study, we encourage the use of the ACOG practice guideline. In addition, knowing factors associated with adverse maternal and perinatal outcomes can guide physicians in patient counselling and providing optimal neonatal care planning.