Risk factors for placenta accreta spectrum in pregnancies conceived after frozen-thawed embryo transfer in a hormone replacement cycle.

OBJECTIVE: Assisted reproductive technology (ART), especially frozen-thawed embryo transfer (FET) in a hormone replacement cycle (HRC), is a risk factor for placenta accreta spectrum (PAS). This study aimed to clarify the risk factors for PAS related to the maternal background and ART techniques in pregnancies achieved after FET in an HRC. STUDY DESIGN: We performed a case-control study in two tertiary perinatal centres in Japan. Among 14,028 patients who delivered at ≥24 weeks of gestation or were transferred after delivery to two tertiary perinatal centres between 2010 and 2021, 972 conceived with ART and 13,056 conceived without ART. PAS was diagnosed on the basis of the FIGO classification for the clinical diagnosis of PAS or retained products of conception after delivery at ≥24 weeks of gestation. We excluded women with fresh embryo transfer, FET with a spontaneous ovulatory cycle, a donor oocyte cycle, and missing details of the ART treatment. Finally, among women who conceived after FET in an HRC, 62 with PAS and 340 without PAS were included in this study. Multivariate logistic regression models were used for case-control comparisons, with adjustment for maternal age at delivery, parity, endometriosis or adenomyosis, the number of previous uterine surgeries of caesarean section, myomectomy, endometrial polypectomy or endometrial curettage, placenta previa, the stage of transferred embryos, and endometrial thickness at the initiation of progestin administration. RESULTS: PAS was associated with ≥2 previous uterine surgeries (adjusted odds ratio, 3.57; 95 % confidence interval, 1.60-7.97) and the stage of embryo transfer (blastocysts: adjusted odds ratio, 2.89; 95 % confidence interval, 1.15-7.26). In patients with <2 previous uterine surgeries, PAS was associated with an endometrial thickness of <7.0 mm (adjusted odds ratio, 5.18; 95 % confidence interval, 1.10-24.44). CONCLUSION: Multiple uterine surgeries and the transfer of blastocysts are risk factors for PAS in pregnancies conceived after FET in an HRC. In women with <2 previous uterine surgeries, a thin endometrium before FET is also a risk factor for PAS in these pregnancies.

Repeated collection of conjoined oocytes from a patient with polycystic ovary syndrome, resulting in one successful live birth from frozen thawed blastocyst transfer: a case report.

Few cases have been reported in which the aspiration of a single follicle led to the recovery of two conjoined oocytes surrounded by a single zona pellucida. This report describes a successful embryo transfer with subsequent live birth derived from conjoined oocytes, and a later pair of conjoined oocytes in the same patient. After oocyte retrieval from a patient with polycystic ovary syndrome, two pairs of conjoined oocytes were collected. One oocyte was fertilized using in vitro fertilization (IVF) and developed to the blastocyst stage. This blastocyst was cryopreserved and later transferred to the uterus after separating the unfertilized conjoined oocyte. A successful pregnancy and healthy live birth was achieved. Two years later, the patient returned for a second IVF; one pair of conjoined oocytes was detected. One of the pair was fertilized and developed to a blastocyst, but was not transferred. We demonstrate that selective fertilization of a mature oocyte from conjoined oocytes by IVF can lead to the development of a blastocyst and subsequent pregnancy and live birth. To our knowledge, this is the second case report of successful live birth from conjoined oocytes. It may be the first case of repeated fertile conjoined oocytes from the same patient.

The Latent Risk of Acidosis in Commercially Available Total Parenteral Nutrition (TPN) Products: a Randomized Clinical Trial in Postoperative Patients.

To evaluate the latent risk of acidosis in commercially available total parenteral nutrition (TPN) products, three types of commercially available TPN products were compared in postoperative patients. Sixty-four hospitalized patients with gastro-intestinal disease who undertook curative gastro intestinal resection were studied prospectively and administered with TPN solutions. Three types of commercially available TPN products were assigned randomly to eligible patients. Serial studies of blood acid-base status, serum electrolytes, and urinary acid-base status were conducted in the three groups administered with different TPN solutions. Patients received appropriate electrolytic solutions on the operation day and TPN solution from 2 to 7 days after operation. There were no differences among any of the serum electrolytes in the three groups. In one group, urinary pH decreased slightly and urinary net acid excretion (NAE) increased significantly after administration. This TPN product contains about 40 mEq/L of non-metabolizable acid to avoid the Maillard reaction that produces a complex of glucose and amino acids. Urinary NAE did not change in the other two groups. These TPN products do not use non-metabolizable acid to adjust pH. The present results suggest that the non-metabolizable acid may be a risk factor of metabolic acidosis.

Chemical zona pellucida thinning with acidified Tyrode's solution: comparison between partial and circumferential techniques.

PURPOSE: To compare effectiveness of two different chemical zona thinning techniques. METHOD: We studied 163 patients who had experienced IVF or ICSI failures in two or more cycles. Patients were assigned to one of three groups: zona intact (n=72), partial thinning (n=59), or circumferential thinning (n=73). Before transfer, the zonae pellucidae of embryos were thinned partially or circumferentially using acidified Tyrode's solution. RESULTS: Implantation rates were 8.9% in the intact zona group, 17.6% in the partial thinning group, and 11.9% in the circumferential thinning group: respective clinical pregnancy rates were 16.7% (12/72), 32.2% (19/59), and 27.4% (20/73). Both rates were significantly higher in the partial thinning group than the intact zona group. For circumferential thinning versus zona intact groups, differences fell short of significance. CONCLUSIONS: Following embryo transfer failure, partial thinning would be recommended over circumferential thinning for successful assisted hatching.

Assisted hatching using a 1.48-µm diode laser: Evaluation of zona opening and zona thinning techniques in human embryos.

Aim: We assessed the effectiveness of assisted hatching using a 1.48-µm diode laser in human embryos, comparing zona opening and zona thinning techniques. Methods: A total of 56 day 3 embryos were assigned randomly to a zona opening group, a zona thinning group, or a control group. We then carried out assisted hatching using the OCTAX Laser Shot system (MTG Medical Technology, Altdorf, Germany) in the first two groups. In the zona opening group, the inner membrane of the zona pellucida was broken to create a full-thickness opening. In the zona thinning group, the inner membrane of the zona pellucida was not breached. After the laser procedure, embryos were cultured to the hatched blastocyst stage. Results: Blastocyst development rates did not differ significantly between the three groups. In the zona opening group, blastocysts were significantly more likely to hatch than those in the control group (P ≤ 0.05) and no arrested hatching of blastocysts was observed. Conclusions: Assisted hatching using a 1.48-µm diode laser in the zona opening technique increases the likelihood of blastocyst hatching in human embryos and does not adversely effect subsequent embryo development. (Reprod Med Biol 2006; 5: 221-226).

Effect of chitosan film containing basic fibroblast growth factor on wound healing in genetically diabetic mice.

Basic fibroblast growth factor (bFGF) has been shown to stimulate wound healing. However, consistent delivery of bFGF has been problematic. We studied the stability of bFGF incorporated into a chitosan film as a delivery vehicle for providing sustained release of bFGF. The therapeutic effect of this system on wound healing in genetically diabetic mice was determined as a model for treating clinically impaired wound healing. A chitosan film was prepared by freeze-drying hydroxypropylchitosan (a water-soluble derivative of chitosan) acetate buffer solution. Growth factor was incorporated into films before drying by mixing bFGF solution with the hydroxypropylchitosan solution. bFGF activity remained stable for 21 days at 5 degrees C, and 86.2% of activity remained with storage at 25 degrees C. Full-thickness wounds were created on the backs of diabetic mice, and chitosan film or bFGF-chitosan film was applied to the wound. The wound was smaller in after 5 days in both groups, but the wound was smaller on day 20 only in the bFGF-chitosan group. Proliferation of fibroblasts and an increase in the number of capillaries were observed in both groups, but granulation tissue was more abundant in the bFGF-chitosan group. These results suggest that chitosan itself facilitates wound repair and that bFGF incorporated into chitosan film is a stabile delivery vehicle for accelerating wound healing.