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Fertilization and normal embryonic and early fetal development
Published in Hung N. Winn, Frank A. Chervenak, Roberto Romero, Clinical Maternal-Fetal Medicine Online, 2021
Asim Kurjak, Ritsuko K. Pooh, Aida Salihagic-Kadic, Iva Lausin, Lara Spalldi-Barisic
Gestational sac can be visualized from the middle of the 5th week of amenorrhea as a small spherical anechoic structure placed inside one of the endometrial leafs (7). Planar mode tomograms are helpful in distinguishing early intraendome-trial gestational sac from collection of free fluid between the endometrial leafs (pseudogestational sac). The 3D sonography enables precise measurement of exponentially expanding gestational sac volume during the first trimester. At the beginning of the 5th week, small secondary yolk sac is visible as the earliest sign of the developing embryo (Fig. 15). Adjacent to the yolk sac, embryo can be seen as a small straight line when it reaches 2 to 3mm in length at the end of the 5th week.
Implantation and Embryonic Imaging
Published in Mary C. Peavey, Sarah K. Dotters-Katz, Ultrasound of Mouse Fetal Development and Human Correlates, 2021
Mary C. Peavey, Sarah K. Dotters-Katz
In humans, the position of the gestational sac should be in the mid to upper uterus. The shape should be round and fairly spherical in its dimensions. In humans, as early as the fifth week of pregnancy, a yolk sac within the gestational sac is the first sonographic confirmation of a developing intrauterine pregnancy. A pseudogestational sac can sometimes be seen in the instance of an ectopic or extra-uterine pregnancy, but would not contain a yolk sac.
How Babies Can Be Polluted
Published in Antonietta Morena Gatti, Stefano Montanari, Advances in Nanopathology From Vaccines to Food, 2021
Antonietta Morena Gatti, Stefano Montanari
In short, it is evident that the particles pass from mother to foetus through the placental barrier and what happens in animals happens in humans. And that's what we found when we dealt with children born with cancer. We have already described several cases of children we studied who were born already ill with cancer in our book Nanotoxicology and Particle Toxicology (Academic Press, 2015}. We have added the case we came across of a baby born with yolk sac cancer (see Chapter 2], While all the other children born with cancer which we have analysed have died, this was operated on early and to date, after more than five years, is in good health.
Study on diagnosis and management strategies on heterotopic pregnancy: a retrospective study
Published in Journal of Obstetrics and Gynaecology, 2023
Yan Zhang, Xiujuan Chen, Yuan Lin, Chengying Lian, Xiumei Xiong
Transvaginal ultrasonography at HP diagnosis revealed that a gestational sac of an IUP without foetal cardiac activity was found in 10 patients (10/40, 25.0%), while with foetal cardiac activity was found in 30 patients (30/40, 75.0%). Moreover, both three patients (3/10, 30.0%) with empty gestational sac and four patients (4/10, 40.0%) with yolk sac for the IUP were ended in early miscarriage. The miscarriage rate of the co-existing IUP was 16.7% (5/30) for patients with IUP cardiac activity at HP diagnosis, and 90.0% (9/10) for patients without IUP cardiac activity; a significant correlation was identified (χ2 = 18.857, p < .001) (Supplementary Table 1). Further logistic regression models indicated that patients following an IUP with foetal cardiac activity at HP diagnosis were identified as an favourable independent factor of live birth (p < .001) (Table 3). However, the rate of miscarriage exhibited no significant association with other factors, such as patients’ age, first TVS-suspected HP, gestational age at diagnosis, HP positions, ectopic gestational mass diameter, EP foetal heartbeat and pelvic haemorrhage volume (Table 3).
Successful hysteroscopic treatment of a cervical heterotopic pregnancy: case report and literature review
Published in Journal of Obstetrics and Gynaecology, 2020
Antonio Rubattu, Valentina Corda, Iside Derosas, Maria Carla Monni, Cristina Nocco, Ambra Iuculano, Giangavino Peppi, Nadia Rosas, Giovanni Ruiu, Giovanni Monni
We describe the case of a 32-year-old nulliparous Caucasian woman who underwent in-vitro fertilisation (IVF) with ICSI for male factor infertility. She was referred to our centre three weeks after embryo transfer (ET) due to the suspicion of a heterotopic twin gestation with both an intrauterine and a cervical pregnancy. The β-hCG level rose appropriately from 462 to 3563 mIU/mL on days 13–17. The woman had persistent severe vaginal bleeding, however, serum β-hCG level continued to rise appropriately. On referral to our centre, a transvaginal ultrasound identified an 8 mm gestational sac with a yolk sac but without an embryo in the uterus, and a coexisting anaechoic dysmorphic area without a yolk sac inside the endocervical canal. A follow-up ultrasound the next day showed a gestational sac with a yolk sac in the cervical canal. At that time, the β-hCG level was 17,453 mIU/mL. Two days later, the scan revealed a gestational sac with a yolk sac of an increased size within the cervix. In coronal section, the intrauterine pregnancy appeared near the right tubal recess and the β-hCG level at this time was 22,255 mIU/mL. Three days after, a transvaginal ultrasound showed a heterotopic pregnancy with a viable intrauterine pregnancy consisting of an embryo with cardiac activity located in the cervix. The corresponding β-hCG level was 27,318 mIU/mL.
A rare pseudo tumour in the extraembryonic coelom in first trimester of pregnancy: ultrasound and pathology
Published in Journal of Obstetrics and Gynaecology, 2019
Seiji Sumigama, Atsushi Enomoto, Satoshi Matsukawa, Takafumi Ushida, Kenji Imai, Tomoko Nakano, Tomomi Kotani, Fumitaka Kikkawa
In a review of normal early human development, there is a ‘primary yolk sac’ and ‘secondary yolk sac’ as embryological terms (Moore and Persaud 2011). At 4 weeks of gestation, there is an embryonic disc consisting of two-layered cells; embryonic epiblasts and hypoblasts. The primary yolk sac is formed from embryonic hypoblasts, and is lined with an exocoelomic (Heuser’s) membrane (cuboidal cells), outside of which is the extraembryonic mesoderm (spindle-shaped cells) (Moore and Persaud 2011; Sadler 2011). Several days later, additional cells are produced by the hypoblasts, migrate along the inside of primary yolk sac and form a new cavity, the secondary yolk sac (Sadler 2011). Until the end of 4 weeks, the primary yolk sac is pinched off and its residue is found in the extraembryonic coelom; however, it is rarely detected by ultrasonography. The ‘yolk sac’ usually detected by ultrasonography after 4 weeks is the ‘secondary yolk sac’ (Kurjak et al. 2008). In this case, the cystic mass was not observed at 4 weeks and was found at 5 weeks of gestation. The timing coincided with the formation of a residual primary yolk sac, and further, the pathological structure consistent with it. Thus, we speculated that the mass was a residual primary yolk sac that had become hyperplastic for some reason.