Higher β-HCG concentrations and higher birthweights ensue from single vitrified embryo transfers

Abstract

To examine the effect of cryopreservation on developmental potential of human embryos, this study compared quantitative β-HCG concentrations at pregnancy test after IVF-fresh embryo transfer (IVF-ET) with those arising after frozen embryo transfer (FET). It also tracked outcomes of singleton pregnancies resulting from single-embryo transfers that resulted in singleton live births (n = 869; with 417 derived from IVF-ET and 452 from FET). The initial serum β-HCG concentration indicating successful implantation was measured along with the birthweight of the ensuing infants. With testing at equivalent luteal phase lengths, the median pregnancy test β-HCG was significantly higher following FET compared with fresh IVF-ET (844.5 IU/l versus 369 IU/l; P < 0.001). Despite no significant difference in the average period of gestation (38 weeks 5 days for both groups), the mean birthweight of infants born following FET was significantly heavier by 161 g (3370 g versus 3209 g; P < 0.001). Furthermore, more infants exceeded 4000 g (P < 0.001) for FET although there was no significant difference for the macrosomic category (≥4500 g). We concluded that FET programme embryos lead to infants with equivalent (if not better) developmental potential compared with IVF-ET, demonstrated by higher pregnancy β-HCG concentrations and ensuing birthweights.

Vitrified-warmed single-embryo transfers may be associated with increased maternal complications compared with fresh single-embryo transfers

“…Whereas the correlation between frozen cycles and LGA is well established, the association with GDM is controversial. Contrary to our findings, Liu et al (2013), Sazonova et al (2012) and Keane et al (2016) reported comparable rates of GDM among singleton pregnancies after fresh and frozen ET. The lack of association between GDM and cryopreservation in previous studies and the weak association found in the current study led us to suspect the association with LGA relates to either the vitrification or the warming process and is not a consequence of GDM.…”

“…Miscarriage rate in our study could be affected by the difference in embryo quality between the two study groups. Higher rates of miscarriage in vitrified-warmed cycles were found by Keane et al (2016) as well. Our finding may be related to the differences in the rate of PCOS between the two groups (16% versus 11%, P = 0.002).…”

LIF level is a predictive marker for clinical pregnancy following IVF-ET of patients with fallopian tube obstruction

“…Moreover, LIF can play an important role in influencing endometrial receptivity and maternal-fetal interface during early pregnancy. β-HCG concentration may be applied as an indicator of potential developmental progress of the embryo [21]. In our study, we also found that pregnancy predictions in combination with LIF and β-HCG are significantly better than their individual predictive power.…”

Live birth outcomes of vitrified embryos generated under growth hormone stimulation are improved for women categorized as poor-prognosis

“…There was no significant difference in outcomes between both agents. Our FET HRT protocols have been described previously in detail [21]. Briefly, from day 1 to 10 patients received estradiol (E2) valerate (Progynova; Bayer, Reading, UK) tablets (4 mg three times per day) and endometrial thickness was graded on day 10 by a transvaginal ultrasound (TVUS) scan.…”