Effect of noninvasive embryo viability testing versus conventional IVF on the live birth rate in IVF/ICSI patients: a study protocol for a double-blind, multicenter, randomized controlled trial.

BACKGROUND: Preimplantation genetic testing for aneuploidy (PGT-A) was demonstrated to be superior to conventional IVF in reducing the incidence of miscarriage and abnormal offspring after the first embryo transfer (ET). PGT-A requires several embryo trophectoderm cells, but its negative impacts on embryo development and long-term influence on the health conditions of conceived children have always been a concern. As an alternative, noninvasive PGT-A (niPGT-A) approaches using spent blastocyst culture medium (SBCM) achieved comparable accuracy with PGT-A in several pilot studies. The main objective of this study is to determine whether noninvasive embryo viability testing (niEVT) results in better clinical outcomes than conventional IVF after the first embryo transfer. Furthermore, we further investigated whether niEVT results in higher the live birth rate between women with advanced maternal age (AMA, > 35 years old) and young women or among patients for whom different fertilization protocols are adopted. METHODS: This study will be a double-blind, multicenter, randomized controlled trial (RCT) studying patients of different ages (20-43 years) undergoing different fertilization protocols (in vitro fertilization [IVF] or intracytoplasmic sperm injection [ICSI]). We will enroll 1140 patients at eight reproductive medical centers over 24 months. Eligible patients should have at least two good-quality blastocysts (better than grade 4 CB). The primary outcome will be the live birth rate of the first embryo transfer (ET). Secondary outcomes will include the clinical pregnancy rate, ongoing pregnancy rate, miscarriage rate, cumulative live birth rate, ectopic pregnancy rate, and time to pregnancy. DISCUSSION: In this study, patients who undergo noninvasive embryo viability testing (niEVT) will be compared to women treated by conventional IVF. We will determine the effects on the pregnancy rate, miscarriage rate, and live birth rate and adverse events. We will also investigate whether there is any difference in clinical outcomes among patients with different ages and fertilization protocols (IVF/ICSI). This trial will provide clinical evidence of the effect of noninvasive embryo viability testing on the clinical outcomes of the first embryo transfer. TRIAL REGISTRATION: Chinese Clinical Trial Registry (ChiCTR) Identifier: ChiCTR2100051408. 9 September 2021.

[Particle Size Distribution of PM Emission from In-use Gasoline and Diesel Vehicles].

Particle size distribution and emission factors from 9 State 3-5 light-duty gasoline vehicles (LDGVs) and 15 State 3-5 heavy-duty diesel vehicles (HDDVs) were tested in this study using a constant volume sampling (CVS) system on a dynamometer. The influences of driving cycles and emission control level on the PM emission factors and particle size distribution were analyzed. The results show that the PM emission factors of the tested LDGVs and HDDVs were (4.1±4.0)×1014 and (5.7±4.3)×1015 kg-1, respectively; the HDDV PM emission factor was (14±7) times less than that of LDGVs. Regarding LDGVs, the PM emission factor under the extra high speed condition was much more than that of the other speed conditions at (5.1±5.0)×1013 km-1, 11.7, 14.1, and 7.3 times more than that under the low, medium, and high speed conditions, respectively. Regarding HDDVs, the emission factor under the high speed condition was 2.5 and 1.4 times that under the low and medium speed conditions, respectively, and was mostly of nuclei-mode particles. At the emission control level of State 3-5, the PM emission factors of LDGVs were (2.7±1.7)×1013, (2.6±1.3)×1013, and (1.6±1.2)×1013 km-1, respectively, and those of HDDVs were (2.2±1.2)×1015, 2.0×1015, and (7.1±2.1)×1014 km-1, respectively. With improvement in emission control level, the particle number emission control of LDGVs and HDDVs generally showed a good downward trend. However, the emission of PM above 110 nm from LDGVs did not improve with the emission control level. Although the quantity emission factor of HDDVs with particle size above 110 nm is relatively low, its harm to the environment cannot be ignored, which should justify necessary attention.