[Impact of different referral timing on the pregnancy outcomes of severe pre-eclampsia in the referral system].
Authors: X. Lin; Z. Yang; F. Q. Shi; Fengqiu Li
Year: 2022

Objective: To explore the impact of different referral timing on postponing early-onset pre-eclampsia (PE), postponing severe pre-eclampsia (SPE), reducing SPE severe complications and improving maternal and neonatal outcomes by analyzing the pregnancy outcomes of SPE patients who were referred from primary hospitals to tertiary referral center in the referral system. Methods: The clinical data of 159 SPE patients who were referred from primary hospitals, treated and then terminated their pregnancy in Peking University Third Hospital from January 2020 to October 2021, were observed and analyzed in this clinical observational study. According to the clinical stage of PE at the time of referral, they were divided into four groups: 38 cases were referred after onset of SPE severe complications (SPE-C group), 72 cases were referred after onset of SPE (a-SPE group), 15 cases were referred after onset of PE (a-PE group) and 34 cases were referred after detection of PE early warning-signs (Warn-s group). And then these 159 cases were divided into different color groups according to the project management system for high-risk pregnant women. Patients of Red color (highest risk) and Orange color (higher risk) were required to be referred to tertiary hospitals (Red-Orange group, 113 cases), and patients of Yellow color (high risk) could be treated under tertiary hospitals (Yellow group, 46 cases). The maternal and neonatal outcomes of different referral timings were analyzed and compared. Results: (1) Pregnancy outcomes of different referral timings grouped by PE clinical stage at the time of referral: the later the referral timing, the higher the rate of SPE severe complications, the shorter the interval from referral to termination of pregnancy. The rate of SPE severe complications in the SPE-C group was significantly higher than those of the other three groups, and the interval from referral to termination of pregnancy in the SPE-C group was significantly shorter than those of the other three groups (all P<0.05). The referral gestational age of Warn-s group was earlier than those of the other three groups (all P<0.05). The average gestational ages for onset of SPE, termination of pregnancy, and onset of SPE severe complications were all after 34 gestational weeks, and were later than those of a-SPE group and SPE-C group; the rates of SPE onset before 34 gestational weeks, SPE severe complications onset before 34 gestational weeks, terminating pregnancy before 34 gestational weeks, neonatal intensive care unit (NICU) hospitalization, and pregnancy giving up before 28 gestational weeks were lower than those of a-SPE group and SPE-C group, the length of NICU stay was shorter than those of a-SPE group and SPE-C group, and its rate of take-home-babies was 100%, significantly higher than those in a-SPE group and SPE-C group (all P<0.05). The gestational ages for onset of SPE and termination of pregnancy in a-PE group were later than those in a-SPE group and SPE-C group, the rates of SPE onset before 34 gestational weeks, terminating pregnancy before 34 gestational weeks, and NICU hospitalization were lower than those of a-SPE group and SPE-C group, the length of NICU stay was shorter than those of a-SPE group and SPE-C group (all P<0.05). (2) Pregnancy outcomes of different referral timings grouped by the color classification of PE clinical characteristics: among the 159 cases of SPE, 113 cases (71.1%, 113/159) were in the Red-Orange group which were required to be referred to tertiary hospitals, and 46 cases (28.9%, 46/159) were in the Yellow group,which were not in the range of referral requirements, but actually referred to the tertiary hospital and eventually developed SPE. Gestational ages for onset of SPE, termination of pregnancy, and onset of SPE severe complications in the Yellow group were later than those of the Red-Orange group, while the rates of SPE onset before 34 gestational weeks, SPE severe complications onset before 34 gestational weeks, terminating pregnancy before 34 gestational weeks, NICU hospitalization, and pregnancy giving up before 28 gestational weeks were lower than those of the Red-Orange group, the length of NICU stay was shorter than that of the Red-Orange group, and its rate of take-home-babies was higher than that in the Red-Orange group (all P<0.05). (3) Analysis of different clinical referral timings in the Yellow group: among these 159 SPE patients, 46 cases (28.9%, 46/159) would be excluded from the range of referral requirements which belonged to the Yellow color grade, but 6 cases still developed SPE severe complications (4 cases in Warn-s group and 2 cases in a-PE group), 17 cases were terminated pregnancy before 34 weeks of gestation (12 cases in Warn-s group and 5 cases in a-PE group), and 23 cases developed SPE before 34 weeks of gestation (17 cases in Warn-s group and 6 cases in a-PE group). (4) Multivariate analysis: referral after detection of PE early warning signs was the independent protective factor for postponing the onset of SPE severe complications (P<0.05). Referral after detection of PE early warning signs and referral after onset of PE were both protective factors for postponing the onset of SPE and early-onset PE (all P<0.05). Conclusions: Different referral timing in the referral system is one of the key points that affect the maternal and neonatal outcomes of SPE. Referral after detection of PE early warning signs and timely referral after onset of PE would reduce early-onset PE, postpone the onset of SPE and reduce the severe complications of SPE. The clinical development and evolution of PE is really complicated, and referral based on specific clinical situations is better than referral based on fixed mode.