Journal of Assisted Reproduction and Genetics

, Volume 35, Issue 8, pp 1537–1542 | Cite as

Brief co-incubation of gametes benefits the outcomes of newborns

  • Ruiqi Li
  • Songbang Ou
  • Nengyong Ouyang
  • Lingyan Zheng
  • Qingxue Zhang
  • Dongzi YangEmail author
  • Wenjun WangEmail author
Assisted Reproduction Technologies



The objective of this study was to determine whether ammonium accumulates in IVF media during fertility process and whether the brief co-incubation of gametes (bIVF) benefited the outcomes of newborns.


Ammonium levels in IVF media during gamete co-incubation were measured and the effects of bIVF on neonatal outcomes were evaluated retrospectively in this study.


A total of 609 live newborns cycles were included in this study. The results showed that ammonium levels in the conventional IVF (cIVF) media was significantly increased than that in bIVF and control media (27.32 ± 5.60 vs 20.71 ± 3.89, P = 0.03; 27.32 ± 5.60 vs 19.46 ± 1.31, P = 0.01, respectively). In the cIVF group, the mean gestational age was significantly lower (37.36 ± 2.29 vs. 37.74 ± 1.94 weeks, P = 0.031) and the incidence of preterm birth (< 37 weeks) was higher than that in the bIVF group (25.80 vs. 17.63%, P = 0.015). Singleton cycles and twin cycles were then analyzed respectively. The gestational age and birth weight of the singleton cycles were similar between the two groups. However, of the twin cycles, the gestational age was significantly decreased and the rate of preterm birth was increased significantly in the cIVF group (35.76 ± 2.31 vs. 36.48 ± 1.73, P = 0.013; 53.33 vs. 31.52%, P = 0.002, respectively).


There is an ammonium accumulation in IVF media during co-incubation of gametes. And bIVF reduces the risk of preterm birth (< 37 weeks), especially with regard to preterm birth of the twin cycles, and seems to be a safe alternative method for improving the neonatal outcomes compared with cIVF.


Ammonium Neonatal outcomes Preterm birth Brief incubation 



The contribution of the laboratory staff in the Fertility Center of Sun Yat-Sen Memorial Hospital is gratefully acknowledged.

Author’s contribution

Ruiqi Li analyzed the data and drafted the manuscript. Songbang O, Nengyong Ouyang, Lingyan Zheng, and Meiqi Mai collected the data. Qingxue Zhang revised the manuscript. Dongzi Yang and Wenjun Wang conceived and designed the study. All the authors interpreted the data.


This study was funded by the National Natural Science Foundation of China (81370680), the National Key R&D Plan of 2017 (Grant No. 2017YFC1001004PCOS), Guangzhou Science and Technology Project 2014 (Grant No. 2014Y2-00512), 2014 Sun Yat-sen University 5010 Project (Grant No: 2014005), Special funds for Public welfare research of Guangdong Province (Grant No. 2014A020213014) and the Natural Science Foundation of Guangdong Province (Grant No. 2015A030313086).

Compliance with ethical standards

Conflict of interest

The authors declare that they have no competing interests.


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Copyright information

© Springer Science+Business Media, LLC, part of Springer Nature 2018

Authors and Affiliations

  • Ruiqi Li
    • 1
    • 2
  • Songbang Ou
    • 1
    • 2
  • Nengyong Ouyang
    • 1
    • 2
  • Lingyan Zheng
    • 1
    • 2
  • Qingxue Zhang
    • 1
    • 2
  • Dongzi Yang
    • 1
    • 2
    Email author
  • Wenjun Wang
    • 1
    • 2
    Email author
  1. 1.Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Sun Yat-Sen Memorial HospitalSun Yat-Sen UniversityGuangzhouChina
  2. 2.Reproductive Medicine Centre, Department of Obstetrics and Gynecology, Sun Yat-Sen Memorial HospitalSun Yat-Sen UniversityGuangzhouChina

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