Reproductive Medicine Center, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China.
Guangdong Provincial Key Laboratory of Reproductive Medicine, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China.
Reprod Biol Endocrinol. 2023 Jun 2;21(1):51. doi: 10.1186/s12958-023-01104-7.
Monozygotic twins (MZTs) are associated with high risks of maternal and fetal complications. Even with the widely used elective single embryo transfer (SET), the risk of MZTs following assisted reproductive technology (ART) treatments remains. However, most studies of MZTs focused on the relevant etiology, with few studies describing pregnancy and neonatal outcomes.
This retrospective cohort study included 19,081 SET cycles resulting from in-vitro fertilization (IVF), intracytoplasmic sperm injection (ICSI), preimplantation genetic testing (PGT) and testicular sperm aspiration (TESA) performed between January 2010 and July 2020 in a single university-based center. A total of 187 MZTs were included in this investigation. The main outcome measures were the incidence, pregnancy and neonatal outcomes of MZTs. Multivariate logistic regression analysis was performed to figure out the risk factors for pregnancy loss.
The overall rate of MZTs from ART treatment in SET cycles was 0.98%. No significant difference was found in the incidence of MZTs among the four groups (p = 0.259). The live birth rate of MZTs in the ICSI group (88.5%) was significantly more favorable than in the IVF, PGT and TESA groups (60.5%, 77.2% and 80%, respectively). IVF resulted in a significantly increased risk of pregnancy loss (39.4%) and early miscarriage (29.5%) in MZT pregnancies compared to ICSI (11.4%, 8.5%), PGT (22.7%, 16.6%) and TESA (20%, 13.3%). The total rate of twin-to-twin transfusion syndrome (TTTS) in MZTs was 2.7% (5/187); however, the TESA group had the highest rate at 20% and was significantly higher than the PGT group (p = 0.005). The four ART groups had no significant effect on the occurrence of congenital abnormalities or other neonatal outcomes in newborns from MZT pregnancies. Multivariate logistic regression analysis revealed that infertility duration, cause of infertility, the total dose of Gn used, history of miscarriages, and the number of miscarriages were not related to the risk of pregnancy loss (p > 0.05).
The rate of MZTs was similar among the four ART groups. The pregnancy loss and the early miscarriage rate of MZTs was increased in IVF patients. Neither the cause of infertility nor the history of miscarriage was correlated with the risk of pregnancy loss. MZTs in the TESA group had a higher risk of TTTS, placental effects influenced by sperm and paternally expressed genes may play a role. However, due to the small total number, studies with larger sample sizes are still needed to validate these result. Pregnancy and neonatal outcomes of MZTs after PGT treatment seem to be reassuring but the duration of the study was short, and long-term follow-up of the children is needed.
同卵双胞胎（MZTs）与母婴和胎儿并发症的高风险相关。即使广泛使用选择性单胚胎移植（SET），辅助生殖技术（ART）治疗后仍存在 MZTs 的风险。然而，大多数关于 MZTs 的研究都集中在相关病因上，很少有研究描述妊娠和新生儿结局。
本回顾性队列研究纳入了 2010 年 1 月至 2020 年 7 月期间在单一大学附属中心进行的体外受精（IVF）、胞浆内精子注射（ICSI）、胚胎植入前遗传学检测（PGT）和睾丸精子抽吸（TESA）的 19081 例 SET 周期中的 187 例 MZTs。主要结局指标是 MZTs 的发生率、妊娠和新生儿结局。采用多变量逻辑回归分析来确定妊娠丢失的危险因素。
ART 治疗 SET 周期中 MZTs 的总体发生率为 0.98%。四组之间 MZTs 的发生率无显著差异（p=0.259）。ICSI 组的活产率（88.5%）明显优于 IVF、PGT 和 TESA 组（分别为 60.5%、77.2%和 80%）。与 ICSI（11.4%、8.5%）、PGT（22.7%、16.6%）和 TESA（20%、13.3%）相比，IVF 导致 MZT 妊娠的流产风险（39.4%）和早期流产（29.5%）显著增加。MZTs 中双胞胎输血综合征（TTTS）的总发生率为 2.7%（5/187）；然而，TESA 组的发生率最高为 20%，明显高于 PGT 组（p=0.005）。四个 ART 组对 MZT 妊娠新生儿的先天性异常或其他新生儿结局无显著影响。多变量逻辑回归分析显示，不孕持续时间、不孕原因、Gn 总剂量、流产史和流产次数与妊娠丢失风险无关（p>0.05）。
四个 ART 组之间 MZTs 的发生率相似。IVF 患者 MZTs 的流产和早期流产率增加。不孕原因和流产史与妊娠丢失风险均无相关性。TESA 组的 MZTs 发生 TTTS 的风险较高，精子和父系表达基因对胎盘的影响可能起作用。然而，由于总例数较小，仍需要更大样本量的研究来验证这些结果。PGT 治疗后 MZTs 的妊娠和新生儿结局似乎令人放心，但研究持续时间较短，需要对儿童进行长期随访。
