Risk for Cesarean section in women of advanced maternal age under the changed reproductive policy in China: A cohort study in a tertiary hospital in southwestern China.

AIM: To describe changed epidemiological features of advanced maternal age (AMA) and to examine the effect of AMA on the risk for Cesarean section (CS) in a Chinese pregnant population. METHODS: This retrospective single-center cohort study investigated the changes of epidemiological features of AMA parturients with respect to the revised reproductive policy in China in 43 702 singleton deliveries with live birth at ≥28 weeks managed from January 2005 to December 2016. We also evaluated the pregnancy outcomes in different age groups and risk factors of CS with multivariate analysis. RESULTS: In this 12-year study period, the average maternal age increased from 28.5 to 30.2 years, and the proportion of AMA raised from 6.5% to 17.2%. AMA was significantly associated with increased risk of adverse pregnancy outcomes, and after adjustment for confounding factors, AMA remained a significant independent risk factor for CS. Furthermore, the effect of AMA in nulliparous women on the risk of CS was more significant than in multiparous women, while the history of previous CS (adjusted odds ratio 39.85) and interdelivery interval ≥10 years (adjusted odds ratio 1.52) also increased the risk of CS in multiparous women. CONCLUSION: AMA increased the risk of a number of adverse pregnancy outcomes, and was independently associated with increased risk for CS. The increasing number of AMA parturients with risk factors is likely to increase CS rate in China in the near future, thus it is imperative to reduce the rate of primary CS as a matter of policy.

Effects of Simulated Mobile Phone Electromagnetic Radiation on Fertilization and Embryo Development.

This study investigated the effects of 935-MHz electromagnetic radiation (ER) on fertilization and subsequent embryonic development in mice. Ovulating mice were irradiated at three ER intensities for 4 h/day (d) or 2 h/d for three consecutive days; the ova were then harvested for in vitro fertilization to observe the 6-h fertilization rate (6-FR), 72-h morula rate (72-MR), and 110-h blastula rate (110-BR). Compared with the control group, the 6-FR, 72-MR, and 110-BR were decreased in the low ER intensity group, but the differences were not significant; in the mid- and high-intensity ER groups, 72-MR and 110-BR in the 4 h/d and 2 h/d subgroups were decreased, showing significant differences compared with the control group. Moreover, the comparison between 4 h/d and 2 h/d subgroups showed significant differences. Mid- and high-intensity ER at 935 MHz can reduce the fertilization rate in mice, and reduce the blastulation rate, thus reducing the possibility of embryo implantation.

Effect of sperm DNA fragmentation on the cumulative live birth rate in patients undergoing in vitro fertilization/intracytoplasmic sperm injection treatment.

BACKGROUND: Sperm DNA fragmentation testing is a valuable tool for predicting male infertility independent of routine semen analysis. However, it remains unclear whether sperm DNA fragmentation affects in vitro fertilization/intracytoplasmic sperm injection outcomes, especially their live birth rates. This study aimed to investigate the effects of sperm DNA fragmentation on the cumulative live birth rates over 1 year of in vitro fertilization/intracytoplasmic sperm injection treatment. METHODS: This retrospective study included 5050 couples who had undergone in vitro fertilization/intracytoplasmic sperm injection treatment from 2016 to 2022. These patients were divided into four groups according to their sperm DNA fragmentation percentages (group 1: sperm DNA fragmentation ≤10%, group 2: > 10% to ≤20%, group3: > 20% to ≤30%, and group 4: > 30%) determined using the sperm chromatin dispersion assay. Both conservative and optimistic methods were used for estimating cumulative live birth rates, the primary outcome, was defined as an ongoing pregnancy leading to live birth that had arisen from all embryo transfers performed within 1 year following the first ovum pick-up. RESULTS: The conservative and optimistic cumulative live birth rates showed no significant differences between sperm DNA fragmentation groups when total patients or in vitro fertilization patients were analyzed while adjusting for the confounders. However, compared with those in the group with low sperm DNA fragmentation values (≤10%), the conservative cumulative live birth rate was significantly decreased in intracytoplasmic sperm injection patients in the group with sperm DNA fragmentation > 30%, and the optimistic cumulative live birth rates were significantly decreased in intracytoplasmic sperm injection patients in the three groups with high sperm DNA fragmentation values (> 10% to ≤20%, > 20% to ≤30%, > 30%). These results were further confirmed by the analyses of smooth curves generated by generalized additive models. In intracytoplasmic sperm injection patients, the cumulative live birth rates decreased significantly as the sperm DNA fragmentation increased (p = 0.034), and these effects were stronger with the increase in female age. A similar pattern of correlation between sperm DNA fragmentation and cumulative live birth rate was found in in vitro fertilization patients, but the correlation was not significant (p = 0.232). DISCUSSION AND CONCLUSION: Sperm DNA fragmentation has a significant effect on the cumulative probability of achieving a live birth during 1 year of treatment involving intracytoplasmic sperm injection.

Effect of 935-MHz phone-simulating electromagnetic radiation on endometrial glandular cells during mouse embryo implantation.

This study examined the impact of 935MHz phone-simulating electromagnetic radiation on embryo implantation of pregnant mice. Each 7-week-old Kunming (KM) female white mouse was set up with a KM male mouse in a single cage for mating overnight after induction of ovulation. In the first three days of pregnancy, the pregnant mice was exposed to electromagnetic radiation at low-intensity (150 µW/cm(2), ranging from 130 to 200 µW/cm(2), for 2- or 4-h exposure every day), mid-intensity (570 µW/cm(2), ranging from 400 to 700 µW/cm(2), for 2- or 4-h exposure every day) or high-intensity (1400 µW/cm(2), ranging from 1200 to 1500 µW/cm(2), for 2- or 4-h exposure every day), respectively. On the day 4 after gestation (known as the window of murine embryo implantation), the endometrium was collected and the suspension of endometrial glandular cells was made. Laser scanning microscopy was employed to detect the mitochondrial membrane potential and intracellular calcium ion concentration. In high-intensity, 2- and 4-h groups, mitochondrial membrane potential of endometrial glandular cells was significantly lower than that in the normal control group (P<0.05). The calcium ion concentration was increased in low-intensity 2-h group but decreased in high-intensity 4-h group as compared with the normal control group (P<0.05). However, no significant difference was found in mitochondrial membrane potential of endometrial glandular cells between low- or mid-intensity groups and the normal control group, indicating stronger intensity of the electromagnetic radiation and longer length of the radiation are required to inflict a remarkable functional and structural damage to mitochondrial membrane. Our data demonstrated that electromagnetic radiation with a 935-MHz phone for 4 h conspicuously decreased mitochondrial membrane potential and lowered the calcium ion concentration of endometrial glandular cells. It is suggested that high-intensity electromagnetic radiation is very likely to induce the death of embryonic cells and decrease the chance of their implantation, thereby posing a high risk to pregnancy.