Incidence and Clinical Features of Fetal Growth Restriction in 4 451 Women with Hypertensive Disorders of Pregnancy
Authors: Zhu Yu-Chun , Lin Li , Li Bo-Ya , Li Xiao-Tian , Chen Dun-Jin , Zhao Xian-Lan , Cui Shi-Hong , Ding Hong-Juan , Ding Gui-Feng , Meng Hai-Xia , Wei Hong-Wei , Sun Xiao-Tong , Xin Hong , Yang Hui-Xia 
Published: September 2020

Abstract

Objective:
To assess the clinical features of fetal growth restriction (FGR) in women with hypertensive disorders of pregnancy in China.

Methods:
This is a retrospective cohort study. The clinical data of 4 451 women with hypertensive disorders of pregnancy were retrospectively collected from 11 tertiary hospitals across ten provinces in China during January 2015 to December 2015. The mean maternal age was (31.0 ± 5.4) years old. Participants were divided into FGR group (n = 670) and non-FGR group (n = 3 781). The incidence and clinical features of FGR, and its correlation with gestational age, previous FGR history, 24-hour urinary protein excretion, and hemolysis, elevated liver enzyme and low platelet count (HELLP) syndrome were analyzed. Student's t-test and Chi-square test were used when comparing clinical features between FGR and non-FGR groups.

Results:
The overall incidence of FGR was 15.1% (670/4 451). The FGR incidence was 22.4% (433/1 937) in women with severe preeclampsia and 18.6% (68/365) in women with chronic hypertension with superimposed preeclampsia, respectively. FGR was more prevalent in women who had preterm births than those who had term births (22.8% (432/1 898) vs. 9.3% (238/2 553), P < 0.001). It was also more prevalent in women with early-onset preeclampsia than those with late-onset preeclampsia (18.4% (189/1 025) vs. 14.0% (481/3 426), P = 0.001). Women with a previous FGR history had a significantly higher FGR incidence than those without an FGR history (66.7% (4/6) vs. 15.7% (250/1 596), P = 0.007). The presence of abnormal results of the umbilical artery Doppler (13% (87/670) vs. 2.4% (89/3 781), P < 0.001) and the middle cerebral artery Doppler (3.3% (22/670) vs. 0.4% (15/3 781), P < 0.001) was higher in the FGR group compared with the non-FGR group, while the presence of increased uterine artery resistance was not statistically different (1.5% (10/670) vs. 0.8% (29/3 781), P = 0.072). The FGR group delivered earlier than the non-FGR group ((35.3 ± 3.0) weeks vs. (36.4 ± 4.3) weeks, P < 0.001) with lower birth weight (1 731.0 ± 574.5) g vs. (2 753.9 ± 902.1) g, P < 0.001, higher fetal or neonatal death (9.4% (63/670) vs. 4.2% (157/3 781), P < 0.001), and higher cesarean section rate (82.5% (553/670) vs. 70.2% (2 656/3 781), P < 0.001). In the FGR group, more neonates had 5-minute Apgar score ≤7 (7.9% (53/670) vs. 3.9% (149/3 780), P < 0.001), with higher neonatal intensive care unit admission rate (48.1% (322/670) vs. 23.3% (881/3 781), P < 0.001). More cases of HELLP syndrome occurred in the FGR group (6.9% (46/670) vs. 3.2% (122/3 781), P < 0.001). Women with FGR had heavier 24-hour urinary protein excretion than those without FGR ((3.9 ± 3.7) g vs. (3.1 ± 4.2) g, P = 0.005).

Conclusion:
In pregnancies with hypertensive disorders, increased risks of FGR are associated with preterm birth, birth before 34 weeks, and a previous FGR history. FGR is related to higher occurrence of abnormal uterine artery Doppler and umbilical artery Doppler. When hypertensive disorders is complicated by FGR, there appears to be higher maternal morbidity including higher rate of HELLP syndrome, cesarean section, and heavier proteinuria, as well as worse neonatal outcomes.