Pilot study establishing a nomogram of yolk sac growth during the first trimester of pregnancy

Abstract

Aim: The yolk sac (YS) has been reported as a reliable predictor of adverse pregnancy outcomes, however, it has always been evaluated cross-sectionally with a single ultrasound per patient. We sought to validate the use of YS dimensions in serial ultrasounds throughout the first 10 weeks of singleton and multiple gestations.Methods: This was a prospective cohort study where YS diameters were serially obtained with 2D ultrasound in singleton and multiple gestations from 5 to 11 weeks. Nonparametric test were used for comparisons with P < 0.05 indicating significance. Results: One hundred ninety-three patients were included, 42 twins (3 monochorionic and 39 dichorionic), 2 triplets (monochorionic twins plus a singleton) and 148 singleton pregnancies (238 total fetuses). There was no difference in YS dimensions in singleton versus multiple pregnancies. Starting at 5 weeks' gestation, the YS increased 0.4 mm (95% CI 0.3-0.5 mm) per week until 10 weeks' gestation. Forty-five fetuses were lost in the first trimester. The risk of pregnancy loss was higher with a large YS until 8 weeks (P ≤ 0.001), while after 8 weeks it was higher with a small YS (P < 0.005). Conclusion: We established a nomogram of YS development during the first 10 weeks of pregnancy. The YS reliably detected pregnancies that ended in loss as early as 6 weeks' gestation. The YS was either smaller or larger than in ongoing pregnancies. While all pregnancies with large YS were lost within 10 weeks, those with smaller YS were lost beyond the first 10 weeks.

The Clinical Value of 3D Ultrasonic Measurement of the Ratio of Gestational Sac Volume to Embryo Volume in IoT-Based Prediction of Pregnancy Outcome

“…This study analysed their gestational sac, yolk sac, and germ biomeasurements. In [ 18 ], the authors studied the relationship between yolk sac shape and pregnancy outcome in pregnant women and found that yolk sac shape was significantly different in pregnancy outcomes. In [ 11 ], the authors believed that yolk sac abnormality could lead to embryo death.…”

“…In [ 17 ], binary logistic regression was utilized for ascertaining whether serum AMH levels played any role in the occurrence of a miscarriage or other independent factors were also involved for miscarriage such as ovarian response, age, and other confounding factors. In [ 18 ], the YS has been testified as a responsible forecaster of adversative pregnancy outcomes. YS diameters were obtained with 2D ultrasound gestations from 5 to 11 weeks.…”

A single cell transcriptomic fingerprint of stressed premature, imbalanced differentiation of embryonic stem cells

“…Increased XEN and decreased ESC growth are hallmarks of stress responses of cultured ESC. It is interesting that ultrasound studies or early post-implantation human embryos show that when yolk sac to embryo size ratios increase, reporting a similar lineage imbalance in vivo, this associates with miscarriage (Detti et al, 2020a;Detti et al, 2020b). These data suggest a similarity in lineage imbalance of in the embryo in vivo, and similar effects in cultured ESC may predict miscarriage.…”

Impact of location on placentation in live tubal and cesarean scar ectopic pregnancies

“…Overall, in women with known last menstrual period in spontaneous pregnancies or known date of ovulation or embryo transfer in pregnancies resulting from ART, a smaller than expected GSD has been reported by all authors as predictive of subsequent miscarriage despite a normal fetal cardiac activity [21][22][23][24][25][26][27]. Smaller CRL [22,28] and lower fetal heart rate (24,28,29] for gestational age have also been reported in pregnancies that subsequently miscarried whereas in those cases the yolk sac size has been described as normal [24], decreased [29] or increased [25,30,31]. The gestational sac and yolk sac sizes starts deviating from normality as early as 6 weeks of gestation followed by changes in CRL and fetal heart rate at 7 and 8 weeks [26].…”