Chengdu Jinjing Maternal and Child Health Hospital, Jinxin Research Institute for Reproductive Medicine and Genetics, No. 3 Sanguantang Road, Chengdu, 610051, People's Republic of China.
Chengdu Xi'nan Gynecology Hospital of Jinxin Medical Group, No. 66 Bisheng Road, Chengdu, 610023, People's Republic of China.
BMC Pregnancy Childbirth. 2021 May 12;21(1):374. doi: 10.1186/s12884-021-03850-1.
Smooth endoplasmic reticulum aggregation (SERa, SER+) has been reported to increase the risk of birth malformations and other abnormal outcomes, miscarriage, and perinatal complications. Other studies, however, suggest that SER+ embryos may develop into healthy infants. One report indicates that 25% of in vitro fertilization (IVF) centers discard SER+ oocytes. Thus, we investigated the effect of SER+ on birth outcomes in IVF and intracytoplasmic sperm injection.
We performed a literature search using PubMed, ScienceDirect, Cochrane, Embase, Ovid, and Scopus. We found a total of 1500 relevant studies between 1978 and 2020 and conducted a meta-analysis to study the effects of SER+ on live births, birth weight, and the number of metaphase II (MII) oocytes retrieved per cycle.
Eleven eligible studies were included. If the SER+ zygote was evaluated again at the embryo transfer (ET) stage, SER+ did not affect birth or infant body weight. Stimulated ovaries producing too many oocytes per cycle were positively correlated with SER+ (OR = 1.28, 95% CI = 0.41-2.15; p = 0.004). SER+ was positively correlated with oocyte maturation rate, and observed heterogeneity in a previous meta-analysis was likely due to maternal age. Our data also showed that SER+ cycles produced more oocytes but achieved the same number of births from ET.
The use of SER+ MII oocytes is rare, with the collection of many oocytes in 1 cycle potentially inducing SER+. SER+ may be more common than we originally thought, as some SER+ is found in all oocytes. Although SER+ positively affected oocyte maturation rate, it did not affect births. We hypothesized that this is because the best embryos are chosen at every step of the process, and the oocytes with the poorest characteristics are removed. We therefore suggest a standard method for measuring SER+. Although embryos produced from SER+ cycles can be used, they should only be transferred when no other suitable embryos are available over several cycles.
内质网聚集（SERa，SER+）已被报道会增加出生缺陷和其他异常结果、流产和围产期并发症的风险。然而，其他研究表明，SER+胚胎可能发育为健康婴儿。有一份报告表明，25%的体外受精（IVF）中心会丢弃 SER+卵母细胞。因此，我们研究了 SER+对 IVF 和胞浆内精子注射中出生结局的影响。
我们使用 PubMed、ScienceDirect、Cochrane、Embase、Ovid 和 Scopus 进行文献检索。我们在 1978 年至 2020 年间共找到了 1500 项相关研究，并进行了荟萃分析，以研究 SER+对活产、出生体重和每个周期中获得的中期 II（MII）卵母细胞数量的影响。
共纳入 11 项符合条件的研究。如果在胚胎移植（ET）阶段再次评估 SER+ 胚胎，则 SER+ 不会影响出生或婴儿体重。每个周期产生过多卵母细胞的刺激卵巢与 SER+呈正相关（OR=1.28，95%CI=0.41-2.15；p=0.004）。SER+与卵母细胞成熟率呈正相关，先前荟萃分析中的观察异质性可能是由于母亲年龄所致。我们的数据还表明，SER+ 周期产生了更多的卵母细胞，但从 ET 获得了相同数量的出生。
SER+ MII 卵母细胞的使用很少，在 1 个周期中采集许多卵母细胞可能会诱发 SER+。SER+可能比我们最初认为的更为常见，因为所有卵母细胞中都有一些 SER+。尽管 SER+ 对卵母细胞成熟率有积极影响，但它并没有影响出生。我们假设这是因为在每个过程步骤中都会选择最好的胚胎，并且去除了特征最差的卵母细胞。因此，我们建议采用一种标准的 SER+测量方法。虽然可以使用来自 SER+周期的胚胎，但只有在几个周期内没有其他合适的胚胎时才应转移。
