Real-world evidence regarding the growth of very premature infants with small for gestational age after birth: a multicenter survey in China
Authors: Huang Xue-Rong , Shen Wei , Wu Fan , Mao Jian , Liu Ling , Chang Yan-Mei , Zhang Rong , Ye Xiu-Zhen , Qiu Yin-Ping , Ma Li , Cheng Rui , Wu Hui , Chen Dong-Mei , Chen Ling , Xu Ping , Mei Hua , Wang San-Nan , Xu Fa-Lin , Ju Rong , Zheng Zhi , Lin Xin-Zhu , Tong Xiao-Mei ,   the Chinese Multicenter EUGR Collaborative Group, Lin Xinzhu , Tian Qianxin , Cui Qiliang , Yuan Yuan , Ren Ling , Shi Bizhen , Wang Yumei , Zhang Jinghui , Zhu Yan , Chen Chao , Zou Jingjing , Li Yuhuai , Zhao Baoyin , Liu Shuhua , Xu Ying , Zhou Wenli , Liu Zhiyong , Gao Jinzhi , Liu Jing , Li Cong , Yang Chunyan , Zhang Yayu , Hu Sile , Yang Zuming , Feng Zongtai , Meng Er-Yan , Shang Li-Hong , Ou Shaoping , Li Gui-Nan , Li Long , Zhang Zhe , Bei Fei , Deng Chun , Su Ping , Luo Ling-Ying , Liu Xiao-Hong , Wang Li-Jun , Yu Shu-Qun 
Published: August 2023

Abstract
Background
To analyze the real-world growth pattern of very premature infants (VPI) with small for gestational age (SGA) after birth by using the ΔZ value of weight at discharge.

Methods
The clinical data were collected from 28 hospitals in China from September 2019 to December 2020. They were divided into the EUGR(Extrauterine Growth Restriction) and the non-EUGR group according to the criterion of ΔZ value of weight at discharge < –1.28.

Results
This study included 133 eligible VPI with SGA. Following the criterion of ΔZ value, the incidence of EUGR was 36.84% (49/133). The birth weight, the 5-min Apgar score, and the proportion of male infants in the EUGR group were lower (P < 0.05). The average invasive ventilation time, cumulative duration of the administration of antibiotics, blood transfusion time, blood transfusion ratio, and total days of hospitalization were significantly higher in the EUGR group (P < 0.05). In the EUGR group, several factors exhibited higher values (P < 0.05), including the initiation of enteral feeding, the volume of milk supplemented with human milk fortifier (HMF), the duration to achieve complete fortification, the cumulative duration of fasting, the duration to achieve full enteral feeding, the length of parenteral nutrition (PN), the number of days required to attain the desired total calorie intake and oral calorie intake, as well as the age at which birth weight was regained. The average weight growth velocity (GV) was significantly lower in the EUGR group (P < 0.001). The incidences of patent ductus arteriosus with hemodynamic changes (hsPDA), neonatal necrotizing enterocolitis (NEC) stage≥ 2, late-onset sepsis (LOS), and feeding intolerance (FI) in the EUGR group were higher (P < 0.05). Multivariate logistic regression analysis showed that birth weight, male, and GV were the protective factors, while a long time to achieve full-dose fortification, slow recovery of birth weight, and NEC stage ≥2 were the independent risk factors.

Conclusion
SGA in VPI can reflect the occurrence of EUGR more accurately by using the ΔZ value of weight at discharge. Enhancing enteral nutrition support, achieving prompt and complete fortification of breast milk, promoting greater GV, reducing the duration of birth weight recovery, and minimizing the risk of NEC can contribute to a decreased occurrence of EUGR.

Trial registration
CHICTR, ChiCTR1900023418. Registered 26/05/2019, http://www.chictr.org.cn.