[Effect of body mass index on the assisted reproductive outcome of frozen-thawed embryo transfer in patients with polycystic ovary syndrome]

Objective: To investigate the effect of body mass index (BMI) on clinical pregnancy and neonatal outcomes in patients with polycystic ovary syndrome (PCOS) during frozen-thawed embryo transfer. Methods: A total of 650 patients with PCOS who received routine in vitro fertilization or intracytoplasmic sperm injection treatment for frozen-thawed embryo transfer from June 2014 to June 2019 in Tianjin Central Hospital of Gynecology Obstetrics were retrospectively analyzed. According to BMI, PCOS patients were divided into group A (18.5≤BMI<23 kg/m², n=253), group B (23≤BMI<25 kg/m², n=167), and group C (BMI≥25 kg/m², n=230). The general information, clinical pregnancy outcomes, pregnancy complications, the incidence of macrosomia and low-birth-weight infants were compared in the three groups, and the influencing factors of neonatal birth weight were analyzed. Results: The embryo implantation rate, clinical pregnancy rate, and ongoing pregnancy rate all showed downward trend with the increase of BMI, but the differences were not statistically significant (all P>0.05). The live birth rate in group C [47.0% (108/230)] was significantly lower than those in groups A and B, with statistical significance (χ²=7.43, P=0.024). The late miscarriage rate was higher in group C [9.4% (13/139)] than in groups A and B (χ²=7.66, P=0.022). The birth rates of macrosomia in groups B [22.2% (16/72)] and group C [21.1% (16/76)] were significantly higher than that in group A, and the difference was statistically significant (χ²=14.15, P=0.001). There was no statistically significant difference in the incidence of gestational diabetes between the three groups (χ²=3.81, P=0.149). The incidence of hypertension disorders complicating pregnancy increased with the increase of BMI, and the difference was not statistically significant (P>0.05). Regression analysis showed that macrosomia was significantly associated with maternal pre-pregnancy BMI and gestational weeks, and the risk of macrosomia increased by 15% (95%CI: 3%-28%) for every increase in maternal BMI. Conclusions: The embryo implantation rate, clinical pregnancy rate, and ongoing pregnancy rate of PCOS patients in frozen-thawed embryo transfer cycles show downward trend with the increase of BMI. Obese patients with PCOS have a significant increase in late miscarriage rate and a significant decrease in live birth rate. The incidence of hypertension disorders complicating pregnancy in PCOS patients in the obese group has an increasing trend, and the birth rate of macrosomia has increased significantly. Therefore, it is recommended that obese women with PCOS lose weight scientifically before pregnancy to improve pregnancy and neonatal outcomes.

[Impact of previous cesarean delivery on pregnancy outcomes of in vitro fertilization and frozen-thawed embryo transfer]

Objective: To investigate the impact of a previous cesarean delivery on pregnancy outcomes of in vitro fertilization and frozen-thawed embryo transfer (FET). Methods: The clinical data of 1 179 patients who received in vitro fertilization and FET in Tianjin Central Hospital of Gynecology Obstetrics from January 2014 to May 2019 and had a history of the previous delivery were retrospectively analyzed. The patients were divided into four groups according to different previous delivery history and the number of embryo transferred: group A (single embryo transfer group with cesarean delivery history, n=338), group B (single embryo transfer group with vaginal delivery history, n=78), group C (double embryo transfer group with cesarean delivery history, n=444), and group D (double embryo transfer group with vaginal delivery history, n=319). The 1∶1 propensity score based on age, body mass index (BMI), infertility duration, basal FSH, basal LH, number of oocytes retrieved and high-quality embryo rate was used to match group A and B (caliper value=0.15), group C and D (caliper value=0.05), and group A and C (caliper value=0.01) respectively to reduce the influence of selection bias. The clinical pregnancy outcomes of patients were compared. Results: (1) Group A and group B were single embryo transfer groups with a total of 77 pairs of matched patients. There were no statistically significant differences in clinical pregnancy rate [42.9% (33/77) vs 45.5% (35/77)], miscarriage rate, preterm birth rate, and neonatal birth weight (all P>0.05). (2) Group C and group D were double embryo transfer groups with a total of 304 pairs of matched patients. The clinical pregnancy rate [42.4% (129/304)] and twin pregnancy rate [9.5% (29/304)] of Group C were significantly lower than those of Group D [53.0% (161/304), 15.5% (47/304) respectively; both P<0.05). There were no statistically significant in miscarriage rate, preterm birth rate and neonatal birth weight between the two groups (all P>0.05). (3) Groups A and C matched 318 pairs of patients. The two groups had no statistical significances in clinical pregnancy rate [38.4% (122/318) vs 45.6% (145/318)], miscarriage rate and preterm birth rate (all P>0.05), but the twin pregnancy rate in group C was significantly higher than that of group A [11.3% (36/318) vs 0.3% (1/318), P<0.01). (4) The occurrence of the low-birth-weight infant were related to gestational age (OR=0.41, 95%CI: 0.32-0.54) and twin pregnancy (OR=4.44, 95%CI: 1.93-10.21), and the occurrence of macrosomia was related to BMI (OR=1.18, 95%CI: 1.06-1.32). Moreover, the previous delivery method was not related to the neonatal birth weight (P>0.05). Conclusions: Patients with different delivery histories receive FET therapy, the pregnancy outcomes of single embryo transfer are not significantly different, and the success rate of double embryo transfer in patients with a cesarean delivery history is low. The neonatal birth weight is not related to the history of the cesarean section. It is recommended that patients with a cesarean delivery history choose elective single embryo transfer to ensure the success rate and to reduce the risk.

[Effect of the number of previous spontaneous abortions on the first in vitro fertilization cycle]

Objective: To investigate the effect of the number of previous spontaneous abortions on the first in vitro fertilization or intracytoplasmic sperm injection (IVF/ICSI) cycle. Methods: A retrospective case-control study was conducted to analyze the clinical data of 1 279 patients who received IVF/ICSI treatment for the first time from July 2014 to July 2018 in Tianjin Central Hospital of Gynecology Obstetrics;they were divided into 0 time group (group A, n=924), 1 time group (group B, n=267) and 2 times group (group C, n=88) for comparison, according to the previous frequency of spontaneous abortions. Results: There were no statistically significant differences in age, basal testosterone, estradiol, progesterone, prolactin and embryo quality in group A, B and C (all P>0.05). The biochemical pregnancy rate of group C (9.1%) was higher than those of the other two groups (4.1% and 4.1%; all P>0.05). The clinical pregnancy rate of group A (42.5%) [>group B (40.4%) and >group C (35.2%)] was not statistically significant(P>0.05).Early abortion rate in group A (8.9%) was<group B (15.7%), also <group C (38.7%), there were significant differences (all P<0.05).The live birth rate of group C (21.6%) was significantly lower than that of group A (35.5%; P<0.05), but the difference between group C and group B (30.7%) was not statistically significant (P>0.05). Conclusions: Women with a history of one- or two-time spontaneous abortion have no obvious effect on embryo quality, and have a negative impact of clinical pregnancy rate, early abortion rate, live birth rate in the first IVF/ICSI cycle; especially for patients with a history of two times spontaneous abortion, early abortion rate has a significant increase, live birth rate decreases significantly, suggesting that patients with a history of two times of spontaneous abortion should find the causes of miscarriage according to the process of recurrent spontaneous miscarriage and receive treatment if necessary before subsequent pregnancy.

[Vestibular-evoked myogenic potentials in healthy guinea pigs]

Objective:To establish detection methods of air-conducted sound elicited vestibular-evoked myogenic potentials (ACS-VEMPs) in guinea pigs, including cervical vstibular-evoked myogenic potential (cVEMP) and ocular vestibular evoked myogenic potential (oVEMP). Method:Eleven healthy (250-350 g) guinea pigs (22 ears) were selected and underwent conventional ACS-cVEMP and ACS-oVEMP examinations. Parameters of waveforms were recorded. Result:The ACS-cVEMP and ACS-oVEMP could be elicited in 77.27% and 59.09% guinea pigs,respectively；threshold was (107.1±14.6)dB SPL and (115.5±15.6)dB SPL for ACS-cVEMP and ACS-oVEMP；n1,p1 latency for cVEMP was (7.4±1.5)ms and (9.3±1.6)ms，(6.4±1.4)ms and (8.1±1.8)ms for oVEMP；amlipude was (15.4±8.6)μV and (11.4±6.0)μV for cVEMP and oVEMP respectively. No statistical difference could be found in above parameters between ACS-cVEMP and ACS-oVEMP (P>0.05). Conclusion:Both ACS-cVEMP and ACS-oVEMP could be elicited in guinea pigs.

[The effects of tympanoplasty on improvements of hearing and tinnitus for chronic otitis media patients with tinnitus]

Objective:The purpose of this study is to investigate the correlation of hearing and tinnitus improvement levels in chronic otitis media (COM) patients after tympanoplasty.Method:Thirty-five cases with COM, accompanied with tinnitus on the affected side or undefined sides, were enrolled and accepted for tympanoplasty between May 2015 and Dec 2016. Audiologic evaluation by pure tone audiometry and assessment of Tinnitus Handicap Inventory scores were conducted in pre-operation and 3 months post-operation. The mean air conduction (AC), boneconduction (BC), air-bone gap (ABG) at 500, 1 000, 2 000 and 4 000 Hz was calculated. THI scores were recorded and analyzed.Result:All the patients healed well and the felthearing was improved and tinnitus symptoms alleviated. There was a significant difference between post-operative THI score (15.0±5.6) and pre-operative score (21.2±7.4), t= 7.8, P< 0.01. Significant differenceswerealso found in comparison of pre-operative AC (41.6±9.9)dBHL and post-operative AC(32.5±10.0)dBHL, t= 5.9, P< 0.01, pre-operative ABG (27.0±7.4)dBHL and post-operative ABG (18.3±7.7)dBHL,t= 6.5, P< 0.01. However, the value of BC in the pre-operation (14.5±5.9)dBHL was almost the same as that in post-operation(13.9±6.0)dBHL, t= 1.2, P> 0.05. Hearing improve levels aboutAC and ABG were positively correlated with the remission degree of tinnitus post-operatively (t= 0.9, P< 0.01).Conclusion:Patients accompanied with tinnitus experienced a remarkableremission in tinnitus and recoveryin hearing levelfollowed bytympanoplasty.Tympanoplasty was a positive treatment for relievingtinnitus in COM patients.

Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate)-based scaffolds for tissue engineering

Development and selection of an ideal scaffold is of importance for tissue engineering. Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) is a biocompatible bioresorbable copolymer that belongs to the polyhydroxyalkanoate family. Because of its good biocompatibility, PHBHHx has been widely used as a cell scaffold for tissue engineering. This review focuses on the utilization of PHBHHx-based scaffolds in tissue engineering. Advances in the preparation, modification, and application of PHBHHx scaffolds are discussed.