Morphologic characteristics of the placental basal plate in in vitro fertilization pregnancies: a possible association with the amount of bleeding in delivery

Abstract

The aim of the present study was to investigate the relationship between assisted reproductive technology procedures, the morphology of the basal plate of placentas, and amount of bleeding in deliveries. Fifty-five whole placentas (fresh-embryo transfer in the in vitro fertilization cycle [n = 6], frozen-thawed embryo transfer in the natural cycle [n = 13] or in the hormonal cycle [n = 10], and age-matched spontaneously conceived pregnancies [n = 26]) were retrospectively enrolled and histologically analyzed. The whole placentas were stored in our pathological division among 512 singleton pregnancies with vaginal deliveries (34-41 weeks of gestation) at Hamamatsu University Hospital. The morphology of the placental basal plate was examined using Azan staining. A total of 20 digital images (each 0.53 mm(2)) of microscopic fields were analyzed per placenta to measure the mean values of the vertical maximum thickness of Rohr and Nitabuch fibrinoid layers and % loss of decidua. The thickness of Rohr fibrinoid layer and % loss of decidua were significantly higher in the frozen-thawed embryo transfer in the hormonal cycle group than in the frozen-thawed embryo transfer in the natural cycle and spontaneously conceived pregnancy groups (each P < .01). The z scores for both the thickness of Rohr fibrinoid layer and % loss of decidua positively correlated with those for the amount of bleeding in deliveries (P < .05 each). Assisted reproductive technology procedures changed the morphology of the placental basal plate, suggesting a possible association with an increase in the amount of bleeding in deliveries.

Identifying a possible factor for the increased newborn size in singleton pregnancies after assisted reproductive technology using cryopreserved embryos, in comparison with fresh embryos

“…In either circumstance, the decidua is underdeveloped in association with restricted fetal growth . One article indicated the association of the thinned decidual layer with pregnancies after a FET in HRT cycles . This seemed to stand in contrast to the current findings that the birthweight of the HRT group was higher relative to the ovulatory group.…”

“…In this regard, the findings from the laboratory of Hamamatsu University in Japan are noteworthy. They revealed that the morphology of the placental basal plate in pregnancies following a FET that was conducted in HRT cycles differs when compared with a FET that was conducted in ovulatory cycles . More precisely, compared with a FET in ovulatory cycles, the placenta that was obtained from a FET in HRT cycles exhibited the thickened Rohr fibrinoid layer that is located between the villous structure and the extravillous trophoblast layer, concomitant with thinning of the decidual layer.…”

“…In addition, another point of discussion should be taken into consideration when it comes to the dissemination of a FET in hormonally regulated cycles. For instance, it is of note that this technology was suggested to be linked with an increased amount of bleeding during birth . Besides, a higher incidence of placenta accreta and pregnancy‐induced hypertension in association with a FET was pointed out .…”

“…The FETs were performed using different cycle regimens; that is, ovulatory cycles with or without ovulation‐inducing agents or artificially prepared cycles by the administration of estrogen alone, followed by estrogen in combination with progestin, which involves ovulation suppression (hormone replacement therapy [HRT] cycles). In this connection, it is interesting to note that the quantitative morphology of the placenta in pregnancies conceived through FET is apparently distinct between the cycle regimens; that is, ovulatory cycles vs HRT cycles . In view of the placenta playing crucial roles for fetal growth, it was asked whether the birthweight from pregnancies using a FET is related to the cycle regimens for embryo transfer.…”

Pregnancy, birth, and infant outcomes by maternal fertility status: the Massachusetts Outcomes Study of Assisted Reproductive Technology

“…These differences have included significantly larger placental weight and higher placental weight/birthweight ratio (51); increased thickness and a higher incidence of hematomas (52, 53), and altered gene expression (54, 55). Nakamura et al (53) reported that the thickness of the Rohr fibrinoid layer and percent loss of decidua were both significantly highest in the hormonal cycles using thawed embryos, with z-scores of both measures positively correlating with the amount of bleeding at delivery.…”