Development of fetal organs and adaptation to extrauterine life

Under unsatisfactory environmental conditions, such as the mother's illness, placental insufficiency, PROM, etc., the fetus must make the transition to extrauterine life from an unfortunate intrauterine existence. The adaptation process of the fetus to extrauterine environment in these cases is extreme importance. In our present investigation, we studied the developmental pattern of the functions of each fetal organ and the specific aspects of fetal metabolism. Using the brush border technique, we clarified that the fetal absorptional function of intestine developed from the 24th week of gestation and reached adult level in 32nd gestational weeks. The fetal renal reabsorption function developed from the 30th week of gestation and reached adult level in 36 gestational weeks. The liver function (enzymatic activity, etc.) remained low during the entire fetal life and developed gradually after birth. Taurine plays an important metabolical role and has a specific transport system during fetal life. The coagulation of vitamin K-dependent factors and activity remained low level at 27-31st gestational week, reaching full term level after 30 days. The switching of HbF to HbA was delayed more significantly in premature infants than in full term infants, but this delay of switching is effectively corrected by the increase of 2.3 DPG in premature infants. Immune response remained immature even in the full term fetus, but the non-specific immune response (NK activity, LAK activity, etc.) developed in the early fetal period and showed characteristic activity. The steroids which originated from the fetal-placental unit related intimately to the continuity of pregnancy and fetal development.     

Continuous transcutaneous carbon dioxide measurement from the fetal scalp during labor and during first minutes of extrauterine life

An electrode for continuous transcutaneous carbon dioxide (tcPco2) monitoring was attached to the fetal scalp in 25 consecutive vaginal deliveries. In six patients the electrode fell off or was deliberately removed when the fetal head was on the pelvic floor, while eight patients were delivered with the electrode in situ, making it possible to study changes in the fetal carbon dioxide level when the fetus changed from placental to lung breathing. The mean recording time was 136 minutes (range 10-348). Fifteen patients were recorded until delivery and analysis of cord blood showed a statistically highly significant correlation between tcPco2 in both umbilical venous and arterial blood. The mean fetal tcPco2 during the late first stage of labor was 56 torr (range 40-75; n = 18). The post partum tcPco2 level in newborns was stable 20 minutes after delivery with a mean level of 51 torr (range 40-60). Fetuses with a normal fetal heart rate tracing showed a lower mean tcPco2 level than fetuses with fetal heart rate tracing abnormalities. The experience with the current technique indicates that both Apgar score and fetal heart rate tracing are rather crude methods to judge fetal blood gas status.     

Fertility disorders attributable to the use of diethylstilbestrol during intrauterine life

A lot has been written about the abnormalities seen in children born to women treated with distilbene during pregnancy. The author reviews the current state of the certainties and the doubts. It seems that the increased number of miscarriages, extra-uterine pregnancies and perinatal deaths are probably due to the maternal treatment which is also responsible for semen abnormalities.     

孕期弓形体感染对胎、婴儿的影响及治疗

目的：研究孕期弓形体感染胎、婴儿的结局，母婴传播途径及治疗。方法：应用ＥＬＩＳＡＩｇＭ方法筛查３８７８例孕妇弓形体近期感染情况。追踪８２例弓形体近期感染孕妇分娩的胎、婴儿预后、收集脐血、羊水、胎盘及尸解的器官组织了解母婴传播途径及病理改变。观察应用螺旋霉素系统治疗孕期弓形体感染者的胎、婴儿预后，并与未治疗组对照。结果：本组孕妇弓形体近期感染发生率为４．４１％（１７１／３８７８），其胎、婴儿出现临床症状为３０．４８％（２５／８２）；孕早期感染以畸胎、流产多见，孕晚期感染表现为早产、低体重儿、黄疸及弓形体感染性肺炎等。从胎盘、羊水、脐血及尸解器官组织中可查出弓形体ＤＮＡ。显示弓形体可通过胎盘感染胎儿，严重者造成器官损害。应用螺旋霉素治疗孕期弓形体感染有效。治疗组先天性弓形体感染发生率低于对照组（Ｐ＜０．０１）。结论：孕妇近期弓形体感染可通过胎盘感染胎儿，造成畸胎、流产、早产、低体重儿及急性弓形体感染症状。螺旋霉素治疗孕期弓形体感染有效。     

Use of atracurium besylate to arrest fetal activity during intrauterine intravascular transfusions

Prevention of movement during intrauterine transfusion is important to facilitate the procedure and to prevent injury to the fetus. We administered atracurium besylate to the fetus via the umbilical vein during 12 intrauterine intravascular transfusions. A dose of 0.2-0.4 mg/kg of estimated fetal weight was administered after needle entry into the umbilical vein. With a dose of 0.2 mg/kg, fetal movement was slowed transiently. Thereafter, 0.4 mg/kg was administered. All recipients were paralyzed for the duration of the procedure. Fetal activity returned 20-130 minutes later.     

Obstetric characteristics and fetal heart rate patterns of infants who convulse during the newborn period

Seizure activity in the immediate neonatal period has been shown to correlate with long-term neurological handicap. The perinatal course of 34 term and 32 preterm infants who developed seizure activity in the neonatal period was compared to that of 66 matched control infants without neonatal seizure activity. The incidence of antenatal complications and abnormal fetal heart rate patterns and the percentages of abnormal labor, operative delivery, and low Apgar scores were significantly greater in the study infants than in the control infants. Earlier onset of seizure activity was seen in term versus preterm infants and term infants with abnormal versus normal fetal heart rate patterns. Management decisions regarding intervention or nonintervention based on fetal heart rate patterns were deemed appropriate in 31 of 34 term infants, yet short- and long-term neurological sequelae were significant.     

Diagnosis of human cytomegalovirus intrauterine infection using fetal cells from maternal blood.

OBJECTIVE: The sensitivity and specificity for the noninvasive prenatal diagnosis of human cytomegalovirus intrauterine infection were estimated by using isolating single fetal cells from maternal peripheral blood. METHODS: Micromanipulation techniques were employed to isolate single fetal nucleated erythroblasts from 273 maternal blood samples. SRY gene and HCMV-DNA in single fetal cells were detected by multiple primed in situ labeling (PRINS) from 76 HCMV-DNA positive samples of maternal peripheral blood. 273 samples of maternal peripheral blood were tested for SRY gene and HCMV-DNA in single fetal cells by primed extension preamplification (PEP) and polymerase chain reaction (PCR). RESULTS: The detection rate of fetal cells from maternal blood was 100% with micromanipulation techniques. The sensitivity of PRINS for SRY gene detection was 97.56% and its specificity was 100%. The sensitivity and specificity of PEP and PCR for SRY gene detection were 97.39% and 99.17%, respectively. The sensitivity of PRINS for HCMV-DNA detection was 92.68% and the specificity was 100%. The sensitivity and specificity of PEP and PCR for HCMV-DNA detection were 95.12%and 100%, respectively. CONCLUSION: The technique for noninvasive prenatal detection of intrauterine infection of HCMV using single fetal cells from maternal peripheral blood by using PRINS and PEP and PCR is more reliable than the CMV-DNA detection in peripheral maternal blood, amniocentesis or percutaneous umbilical blood sampling.     

Complications in the transition from fetal to neonatal life

The transition from fetus to neonate is a time of significant physiologic adaptation. In addition to the normal physiologic tasks of transition, some neonates must also cope with underlying congenital abnormalities, birth injury, or disease. Careful assessment and astute nursing care are needed during the period of transition to ensure that the neonate who is experiencing problems with transition is recognized and appropriate interventions are initiated. This article examines the physiology of transition and discusses factors placing the neonate at risk of illness. A plan of care for neonates experiencing symptoms of underlying disease during transition is presented.     

Measurements of anterior fontanelle during the fetal period.

In this study, we aimed to determine the development of the anterior fontanelle during the fetal period by morphometric measurements. One hundred and five (49 males, 56 females) human fetuses were obtained from Isparta Maternity and Pediatric Hospital. The gestational age ranged from 11 to 40 weeks. In all cases, head circumference, head length and biparietal diameter were recorded. The anterior fontanelle, transverse and longitudinal diameters were measured, and the mean anterior fontanelle size and the anterior fontanelle area were calculated. A significant positive correlation was found between the gestational age and all parameters. During the fetal period, the anterior fontanelle area gradually increased with head circumference. There was a sharp increase in third trimester in the area anterior fontanelle. In the present study, there was no significant difference between sexes regarding the all parameters measured or calculated. The mean anterior fontanelle size was larger than that recorded in previous studies for both sexes. As presented in our study, the dimensions of the anterior fontanelle for each gestational age will be useful in the understanding of development and anatomical variation. It may also be useful in the diagnosis of cranial maldevelopment.     

Fetal echocardiography using transvaginal and transabdominal probes during the first period of pregnancy: a comparative study

The authors compare the diagnostic possibilities of fetal transabdominal echocardiography versus transvaginal echocardiography. A larger diagnostic capacity is verified in different gestation ages with transvaginal probe between the 11th and 14th week of gestation. The results are emphasized by colour Doppler.     

Growing of caecum and vermiform appendix during the fetal period

OBJECTIVE: The aim of this study is to investigate the growing of the caecum and the vermiform appendix during the fetal period in human fetuses and the relation between growing and shape of the caecum and the localization of the vermiform appendix. METHODS: 40 male and 40 female externally normal-looking fetuses were studied between 10 and 40 weeks of gestation and were subdivided into fetuses of the 1st, 2nd, and 3rd trimesters and full-term fetuses. The parameters of interest included covering of the caecum with peritoneum, shape of the caecum (long tube, symmetric saccule, asymmetric saccule, extremely large right side--atypical), axial length and width of the caecum localization of the vermiform appendix, length of vermiform appendix and length of the meso-appendix. RESULTS: There was a difference in covering of the caecum with peritoneum between males and females; the caecum was predominantly tube shaped during the fetal period, with the asymmetric saccule towards the end of the fetal period; the localization of the vermiform appendix was subcaecal (39%) during the fetal period and postileal (34%) in female fetuses and subcaecal (48%) in male fetuses--the localization of the vermiform appendix changed according to the caecum shape during the fetal period; we found significant differences in the measurements of vermiform appendix, meso-appendix, and caecum among 1st-, 2nd-, and 3rd-trimester fetuses and full-term fetuses. CONCLUSIONS: There was an increase in the measurements for vermiform appendix, meso-appendix, and caecum with increasing gestational age; the localization of the vermiform appendix depended on the shape of the caecum, was different from that of adults and different between sexes, and there was also a significant difference in covering of the caecum with peritoneum between both sexes.     

A piece in the puzzle of intrauterine fetal death: Pathological findings in placentas from term and preterm intrauterine fetal death pregnancies

Objective.?To compare pathological findings of placentas from term and preterm pregnancies complicated by intrauterine fetal death (IUFD).

Study design.?A retrospective cohort study was conducted including deliveries complicated by IUFD. A comparison was made between placentas from term and preterm (<37 weeks' gestation) pregnancies complicated by IUFD. A second analysis was undertaken comparing IUFD placentas delivered before and after 34 weeks' gestation. Uteroplacental insufficiency was defined when one or more of the following pathological features were found: placental infarct, poor vascularity of the chorionic villi, intravascular thrombi and vascular occlusion.

Results.?During the study period, 849 placentas of IUFD were examined. Gross and microscopic pathological finding were noted. When comparing gross and microscopic findings in term and preterm (<37 weeks) IUFD placentas, higher rates of calcifications, tissue congestion and cellular metaplasia were found in term vs. preterm placentas. Significantly increased rates of poor tissue vascularity, placental vascular occlusion and uteroplacental insufficiency were demonstrated in preterm IUFD placentas. When comparing pathological findings in IUFD placentas delivered before and after 34 weeks' gestation, higher rates of abnormal cord insertion, calcifications, tissue congestion, infarcts and intravascular thrombi as well as poor tissue vascularity and placental vascular occlusion were demonstrated in IUFD placentas delivered before 34 weeks. Regardless of gestational age at the time of IUFD in more than 90% of placentas vascular wall thickening was found. A third of both term and preterm placentas demonstrated histological chorioamionitis.

Conclusions.?A vast majority of IUFD placentas reveal numerous pathological findings that reflect uteroplacental insufficiency and abnormal blood supply. Different characteristics were noted in term and preterm placentas of pregnancies complicated by IUFD. Better definition of causes and associated placental pathological findings of IUFD might aid clinicians in counseling such patients regarding the reason and risk of recurrence in subsequent pregnancies.     

Spectral analysis of heart rate variability: an emerging tool for assessing stability during transition to extrauterine life

Transition from fetal to neonatal life is likely the most physiologically demanding time of life. Complex changes in major organ system functioning and reorganization of metabolic processes must occur rapidly to achieve postnatal homeostasis. Identifying the neonate with subtle signs of unsuccessful transition is a challenge to the perinatal health care provider. Alterations in fetal or neonatal heart rate and heart rate variability may serve as an indicator of the neural control influencing cardiac function and a sensitive indicator of compromised health. Evaluation of the neural control of the heart can be done noninvasively and provides a discriminating measure of the level of stress vulnerability the fetus or newborn may be experiencing. This article reviews the origins of physiological variability of the fetal and neonatal heart rate in the transition to extrauterine life. The technique of spectral analysis as a new tool for surveillance of the at-risk fetus and neonate is then introduced, and implications for clinical practice and future research avenues are discussed.     

Major aspects of direct fetal electrocardiography with regard to the diagnosis of intrauterine fetal status

The possibilities and limits of direct fetal electrocardiography are described, which result from the estimation and interpretation of only one ECG lead in the diagnostics of disorders in excitation development, conduction and repolarisation and in the as early as possible detection of heart defects.