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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
The primordial heart starts to beat at 6 weeks, and rapid fetal growth and organogenesis occurs from weeks 6–10. Transvaginal ultrasonography can detect fetal cardiac activity as early as 34 gestational days, or as early as a CRL length of 1.6 mm. Cardiac activity should be routinely detected when the human embryo has reached 4–5 mm in length. The absence of a heart beat when the CRL is >4 mm confirms a non-viable fetus (12). Findings suspicious for, but not diagnostic of pregnancy failure, CRL of <7 mm and no heartbeat. In humans, the crown rump length at 10 weeks is approximately 30 mm. In humans, the amnion is not visible until at least CRL of 7 mm, or approximately 7 weeks gestational age.
Implantation and In Utero Growth
Published in Arianna D'Angelo, Nazar N. Amso, Ultrasound in Assisted Reproduction and Early Pregnancy, 2020
Kugajeevan Vigneswaran, Ippokratis Sarris
Following on from the appearance of the YS, the next structure that becomes visible within the chorionic sac is the early embryo. Ultrasound can detect the presence of an embryo from 5 to 6 weeks of gestational age, where it is first seen as a linear echogenic structure measuring 2–3 mm lying alongside the YS. From the gestational age of 5 to 9 weeks, there is rapid embryonic development and organogenesis, and the “fetal pole” can be measured along its long axis. The term crown-rump length had been used to denote the size of the embryo at this stage; however, these anatomical structures are not possible to differentiate until 10 weeks of gestation.
Pathoanatomy of congenital clubfoot
Published in R. L. Mittal, Clubfoot, 2018
Methods: Crown-rump length of fetuses was measured for determining the gestation period. Lower limbs were amputated above knee and preserved in jars containing formalin and duly labeled from 1-A to 15-A for abnormal feet and from 1-N to 15-N for control feet. After removing the skin, muscles were dissected out. Origin direction and insertion of all the leg muscles, that is, tibialis anterior, extensor digitorum longus, extensor hallucis longus, peroneous longus, peroneous brevis, extensor hallucis longus, peroneous longus, peroneous brevis, gastro-soleus, tibialis posterior, flexor hallucis longus, and abductor hallucis, were studied. However, extensor and flexor digitorum longus were examined for their origin alone as they were divided where they split into various slips before going to their insertions into toes. After removal of the muscles, they were tagged with labels for identification. The tendon length, muscle length, and muscle mass of each muscle was measured with the help of a Vernier caliper and compared with the control. Then, the ligaments and joints were studied. In the ligaments, the spring ligament, the trio (deltoid ligament, conjoint posterior capsule of the ankle joint/subtaloid joints, and posterior talo-fibular ligament), besides the plantar ligaments and all other ligaments including toe joints were studied. Detailed anatomy of various joints (ankle, subtaloid, talo-calcaneo-navicular joint, calcaneo-cuboid, and others) was studied.
First-trimester maternal renin-angiotensin-aldosterone system activation and the association with maternal telomere length after natural and IVF/ICSI conceived pregnancies: the Rotterdam periconception cohort
Published in Hypertension in Pregnancy, 2023
D. Aoulad Fares, R.E. Wiegel, A.J. Eggink, J.B.J. van Meurs, S.P. Willemsen, A.H.J. Danser, R.P.M. Steegers-Theunissen
Naturally conceived pregnancies were dated based on the first day of the last menstrual period with a regular cycle between >25 and <35 days. In IVF/ICSI pregnancies, GA was calculated from oocyte retrieval day plus 14 days or, for cryopreserved embryo transfer, from the transfer day plus 19 days. Gestational age was estimated using crown – rump length (CRL) in pregnancies with irregular cycles, when the last menstrual period was unknown, or when gestational age based on last menstrual period differed by more than 6 days from the calculated gestational age based on CRL. Maternal characteristics, medical and obstetrical history and lifestyle behaviors were obtained from a self-reported questionnaire and a personal interview at the study. Entry visit maternal blood pressure, weight, and height were standardized and measured at the same visit. Written informed consent was obtained from all study participants during enrollment. Venous blood samples were drawn from all mothers at 9 and 20 weeks of GA. The study protocol was approved by The Central Committee on Research involving Human Subjects and the institutional review boards of all participating hospitals (15 October 2009; MEC-2004-227). Written informed consent was obtained from all study participants at enrollment.
The predictive value of maternal serum AFP to PAPP-A or b-hCG ratios in spontaneous preterm birth
Published in Journal of Obstetrics and Gynaecology, 2022
Ebru Celik, Rauf Melekoğlu, Arzu Baygül, Uzeyir Kalkan, Yavuz Şimşek
This was a prospective observational study recruiting a low-risk population of pregnant women attending the maternity care unit the Turgut Ozal Medical Center, Inonu University from July 2014 to January 2016 for the first trimester screening test for aneuploidy. Biochemical markers (free β-hCG and PAPP-A) in maternal serum were measured during the first trimester screening test. Blood tests for AFP were also performed to evaluate the association with sPTB. The definite gestational age was determined using crown-rump length measurements. Maternal demographic and clinical characteristics related to pregnancy and birth outcomes were collected from electronic databases. This study was approved by the Inonu University Medical School Ethics Committee (2013/8). Written informed consent was obtained from all the participants.
The outcome of the vein of Galen aneurysmal malformation cases diagnosed prenatally
Published in Journal of Obstetrics and Gynaecology, 2022
Gurcan Turkyilmaz, Resul Arisoy, Sebnem Turkyilmaz, Emre Erdogdu, Altug Semiz
The present study has a retrospective design conducted in Şisli Memorial Hospital, Istanbul and Van Education and Research Hospital, between January 2017 and January 2020. Gestational age was based on measuring crown-rump length or a specific date of the last menstrual period for all pregnancies. The ultrasonography (US) examinations were performed with high-quality ultrasound equipment (Voluson E8, Kreztechnick AG, Zipf, Austria). VGAM was defined as an anechoic round or ovoid structure located in the midline of the posterior part of the third ventricle. Colour or Power Doppler US was used to reveal the vascular nature of the lesion. VGAM was confirmed with the demonstration of high-turbulent flow within the malformation. In all cases, the foetal neurosonography was performed transabdominally in axial, sagittal and coronal planes, as described in the International Society of Ultrasound in Obstetrics and Gynaecology Guideline 2007 (ISUOG 2007). Also, transvaginal foetal brain examination was performed on all of the foetuses, which were cephalic presentations. A detailed scan was performed in all cases to rule out associated anomalies. The study was conducted under the Declaration of Helsinki. Local ethics committee approval was obtained.