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Amniocentesis
Published in Hung N. Winn, Frank A. Chervenak, Roberto Romero, Clinical Maternal-Fetal Medicine Online, 2021
Aris Antsaklis, Marianna Theodora
Amniocentesis is mainly performed during the second trimester but can be performed also during the third trimester when certain indications stand. Amniocentesis for prenatal diagnosis of genetic diseases of the fetus is traditionally carried out between 15 and 18 weeks of gestation when the fundus of the uterus is easily accessible. Additionally in this gestational age, the volume of amniotic fluid is 150 to 200mL, which permits the removal of 15 to 20mL of amniotic fluid, which is adequate for this test without creating problems. Moreover, at this gestational stage, the relationship between the viable and nonviable cells of the amniotic fluid is the optimal in order to have results. For the above reasons, amniocentesis should be carried out at this time (6). Early amniocentesis (between 11 and 14 weeks) has been associated with increased risk of fetal malformations, mainly clubfeet, and has been abandoned.
The Role of Toll-Like Receptor Signaling in the Pathogenesis Of NEC
Published in David J. Hackam, Necrotizing Enterocolitis, 2021
Maame Efua S. Sampah, David J. Hackam
The physiological relevance of these observations is borne out by the observations that both breast milk and amniotic fluid can inhibit TLR4, two fluids that interact with the gut at times of elevated TLR4 expression. Breast milk is a powerful inhibitor of TLR4, which explains in part its protective benefit against NEC (6, 45, 46). The protective effect of TLR4 for NEC may be attributed to the presence of either epidermal growth factor (47) or human milk oligosaccharides (8, 48, 49), which both prevent NEC by blocking TLR4. Amniotic fluid also effectively blocks TLR4 signaling in both mice (50) and piglet models (51), an observation that may explain how the fetus may be protected from in utero NEC development by swallowing amniotic fluid and thus being constantly exposed to a TLR4-blocking agent during times when TLR4 expression is high. The topical exposure of the gut to amniotic fluid would be expected to render the fetal intestine immune tolerant, thus allowing gut development to occur. In support of this concept, we administered amniotic fluid to mice and piglets in models of NEC and achieved significant gut protection (50, 51). The protective benefit of amniotic fluid for NEC and its ability to inhibit TLR4 were found to be attributable to its expression of epidermal growth factor (EGF), which is high in amniotic fluid and breast milk (47). These findings suggest that strategies designed to generate a synthetic amniotic fluid may serve as a novel NEC prevention or treatment strategy.
Xenogeneic Donkey-In-Horse Pregnancy Created by Embryo Transfer
Published in Gérard Chaouat, The Immunology of the Fetus, 2020
W. R. Allen, Julia H. Kydd, D. F. Antczak
But despite this early developmental abnormality, the donkey conceptus continues to grow and develop during the next 30 d. However, placentation usually does not proceed normally, and the expanding allantochorion lies closely apposed to the endometrium without the customary interdigitation between allantochorionic villi and endometrial crypts. After about Day 65 of gestation, increasing numbers of lymphocytes and other leukocytes begin to accumulate in the subepithelial endometrial stroma throughout the area of endometrium in contact with the enlarging donkey allantochorion (Figure 10). Coincidentally, the fetus becomes increasingly cachectic in appearance, and the amniotic fluid assumes a claret color due to hemolysis of fetal red blood cells. Exocrine secretory material accumulates between the endometrium and the unimplanted allantochorion as the latter becomes increasingly pale and flaccid due to the failing fetal circulation. Eventually, between Days 80 and 95 in most cases, the dead and autolyzing conceptus is aborted (Figure 11), when the cervix relaxes in response to a coincidental fall in peripheral plasma progesterone concentrations to baseline.45
Cerebroplacental doppler ratio and perinatal outcome in late-onset foetal growth restriction
Published in Journal of Obstetrics and Gynaecology, 2022
Ozge Kahramanoglu, Oya Demirci, Mucize Eric Ozdemir, Agnese Maria Chiara Rapisarda, Munip Akalin, Ali Sahap Odacilar, Hayal Ismailov, Gizem Elif Dizdarogullari, Aydin Ocal
The data on maternal age, parity, body mass index, gestational age at diagnosis, foetal sex, obstetric complications such as hypertensive disorders, gestational diabetes mellitus, amniotic fluid volume, premature rupture of membranes, gestational age at delivery, delivery mode, Caesarean indication, neonatal birth weight, Apgar scores, cord pH and neonatal intensive care unit (NICU) admission were collected prospectively. Oligohydramnios was defined as no vertical pocket of amniotic fluid more than 2 cm or an amniotic fluid index 5 cm or less. Foetal distress was defined as suspected foetal hypoxia which was observed indirectly by electronic foetal heart rate monitoring. Adverse perinatal outcome (APO) was defined as the presence of one of the following: foetal distress, NICU admission, an Apgar score of less than 7 at 5 min after birth, cord pH less than 7.1, and neonatal death. Foetal distress was defined as the presence of one of the following: baseline heart rate of <100 or >170 bpm, persistence of heart rate variability of <5 bpm for more than 40 minutes, severe variable decelerations, prolonged decelerations, or late decelerations.
Predicting previable preterm premature rupture of membranes (pPPROM) before 24 weeks: maternal and fetal/neonatal risk factors for survival
Published in Journal of Obstetrics and Gynaecology, 2022
Aylin Günes, Hüseyin Kiyak, Semra Yüksel, Gökhan Bolluk, Rabia Merve Erbiyik, Ali Gedikbasi
The amniotic fluid volume had a significant influence on pregnancy outcomes and neonatal complications. Although spontaneous healing of foetal membranes occurs in 1–2% of gestations after amniocentesis and 5–30% of gestations after fetoscopy, spontaneous resealing is infrequent after spontaneous rupture of membranes (Devlieger et al. 2006; Jain and Sciscione 2011). We demonstrated a statistically significant relationship between neonatal survival and the presence of oligo- or an-hydramnios (p = .001 and p = .013, respectively). There was a strong relationship between oligohydramnios or anhydramnios and poor neonatal survival (Shenker et al. 1991; Kilbride and Thibeault 2001; Spong 2001; Muris et al. 2007; Waters and Mercer 2009; Williams et al. 2009; van Teeffelen et al. 2010; Williams et al. 2012). Specifically, we found an anhydramnios rate of 6.73% in surviving infants and 28.3% in non-surviving infants. In a study that included 71 pregnancies with severe persistent oligohydramnios and PPROM prior to 25 weeks’ gestation, 51 infants survived, 11 had pulmonary hypoplasia, and 15 had joint contractures or positional limb deformities. The short-term outcomes of the surviving infants were good (Dinsmoor et al. 2004); however, all deaths in another study occurred in pregnancies in which the largest pocket was <2 cm (Williams et al. 2009). Other studies with PPROM greater than 26 gestational weeks showed similar unfavourable outcome for neonatal morbidity and mortality for amniotic fluid index less than 5 cm (Mousavi et al. 2018).
Physiology of intra‐abdominal volume during pregnancy
Published in Journal of Obstetrics and Gynaecology, 2021
Aleksei Petrovich Petrenko, Camil Castelo-Branco, Dimitry Vasilevich Marshalov, Alexander Valerievich Kuligin, Yuliya Sergeevna Mysovskaya, Efim Munevich Shifman, Adam Muhamed Rasulovich Abdulaev
In our study, the uterus represented 0.65% of the IAV at the beginning of pregnancy, similar to the results of Sheth et al. (2017). However, with an increase of 143.5-fold at full-term, the uterus represents 55.97% of the IAV. This gain may be explained by changes observed in placenta, amniotic fluid and the foetus along pregnancy. Placental growth occurs in three phases: a linear increase up to week 24 (∼150 g), followed by a steeper, linear increase during the third trimester and reaching a plateau at term (∼600–700 g, range 500–1000 g; Almog et al. 2011). Amniotic fluid also accumulates to up to 3 L until the end of a healthy pregnancy (Wallace et al. 2013). Finally, the foetus grows at a relatively consistent speed of ∼1 kg by the 28th week of gestation, and thereafter, over the next 12 weeks, the foetus gains more than two-thirds of its final weight (∼2.5 kg; Institute of Medicine and National Research Council 2009; Most et al. 2018).