Parturition and Fetal Adaptation

The fetus as "patient" during labor and birth has become an increasingly important concept during the past 20 years. However, what is understood about fetal status during labor and how the fetus prepares for its approaching separation from its mother? Current information indicates that not only is the term fetus well prepared for the adaptation to extrauterine life, but this transition is facilitated by normal labor.     

母血中分离检测胎儿细胞的研究进展

进入母体血循环的胎儿细胞有4种.使用有效的方法从正常与异常妊娠母血中分离富集极少量的胎儿有核红细胞、滋养细胞、淋巴细胞和粒细胞.目前国外采用较多的有荧光激活细胞分选法、磁活化细胞分选法、免疫磁珠分离法、密度梯度离心法.分子生物学方法的引入.特别是聚合酶链反应及其衍生技术和荧光原位杂交技术提供了从母血中检测胎儿细胞敏感的方法并在无创伤性产前诊断方面得到一定的应用.     

Maternal Hypothermia and Persistent Fetal Bradycardia During the Intrapartum Process

Maternal hypothermia can be correlated with persistent fetal bradycardia. The improvement of the maternal hypothermic state and the subsequent alleviation of fetal bradycardia are presented in two case reports. A possible consequence of unrelieved maternal hypothermia at delivery, neonatal cold stress, is discussed in a third case report. Neonatal complications requiring interventions may ensue after cold stress.     

The Effects of Qi Exercise on Maternal/Fetal Interaction and Maternal Well-Being During Pregnancy

ObjectiveTo investigate the effects of Qi exercise on maternal outcomes during pregnancy.DesignA prospective, two-group, quasi-experimental, pretest/post test design was used.SettingA convenience sample was recruited from one women's wellness center and one women's health clinic in Seoul, Korea.ParticipantsParticipants were healthy pregnant women at more than 18 weeks gestation. A total of 70 women were included in the final analysis.MethodsQi exercise was carried out for 90 minutes, twice a week for 12 weeks. Study outcomes were measured by the Intrapersonal Communication Questionnaire (Talking to Your Baby), Zung's Self-rating Depression Scale (ZSDS), the State Trait Anxiety Inventory (STAI), and the Pregnancy Mild Discomfort Index. Analysis of covariance was used to compare outcomes between groups, after adjusting for baseline scores.ResultsThe Qi exercise group had higher post test maternal/fetal interaction and lower maternal depressive symptoms and physical discomfort scores than the control group. There was no difference in anxiety.ConclusionThe findings suggest that the holistic approach of Qi exercise may positively influence maternal/fetal interaction and mother's health. Whether these beneficial effects can be sustained throughout pregnancy requites additional research.     

孕妇外周血中胎儿有核红细胞的出现频率及其与孕周的关系

目的 探讨用检测孕妇外周血中的胎儿有核红细胞（ＮＲＢＣ）进行无创性产前诊断的最佳时间。方法 对４４名孕龄６～４０周的孕妇外周血进行不连续密度梯度离心,将分离后的细胞进行制片,显微镜下行有核红细胞计数,然后用显微操作法一一获取,进行Ｙ染色体特异性ＤＹＺ１基因的聚合酶链反应（ＰＣＲ）,以确定其胎儿来源。结果 ４４名孕妇中有１７例其外周血中检出有ＮＲＢＣ,分布于妊娠第９～２６周,其中以妊娠第１１～２０周     

Metabolism of Cocaine by Cholinesterase During Pregnancy: Maternal and Fetal Activity

The objective of the present study was to analyze the metabolism of cocaine during pregnancy in vivo. Pregnant rats were injected with cocaine (25 mg/kg). Two treatment groups of 20 rats each were established. One group received cocaine only, and the other received cocaine plus anticholinesterase (X0.6 ud). Four animals per treatment group were sacrificed at five different time periods (0, 25, 45, 90, 135 min). Maternal blood was collected at sacrifice as were placentae and fetal tissues (brain, liver). Drug (cocaine and metabolites) concentrations were analyzed by dual capillary column gas chromatography (GC) fitted with FID and NPD detectors, and their identity verified by GC/mass spectrometry. We found that cocaine was metabolized differently in maternal and fetal compartments. Maternal metabolism was predominantly through the cholinesterase pathway. Fetal metabolism exhibited no evidence of cholinesterase activity with the predominant biotransformation of cocaine being through fetal liver n-demethylase because norcocaine was the primary metabolite detected in fetal tissues. Over time, norcocaine accumulated in the fetal brain more than any other organ. This effect was enhanced in the anticholinesterase treatment group, probably due to blunted maternal metabolism of the drug that resulted in more cocaine being transferred to the fetus. Norcocaine was a major fetal metabolite of cocaine. We hypothesize that fetal damage due to maternal cocaine exposure may be due in part to fetal metabolism of the drug to a physiologically more active metabolite, norcocaine. This effect was enhanced in the group that received anticholinesterase before cocaine was administered, implying a pharmacogenetic role in cocaine-associated fetal morbidity as result of maternal and placental metabolic activity.     

The Incidence of Maternal Artefact During Intrapartum Fetal Heart Rate Monitoring

ObjectiveTo determine the incidence of maternal heart rate artefact (MHRA) when monitoring fetal heart rate (FHR) in labour and to determine obstetrical factors associated with MHRA.MethodsIn a prospective observational study, maternal and fetal heart rates were displayed simultaneously to document the superimposition of the maternal heart rate (MHR) on FHR tracings. All women in labour who were undergoing external fetal monitoring (EFM) at the Ottawa Hospital from October 2011 to March 2012 were eligible. Every episode of MHRA was documented and classified according to its clinical significance. Wilcoxon test, t tests, and chi-square tests were used to identify time-related differences and obstetrical factors (epidural analgesia, fetal presentation, multiple gestation, maternal BMI, umbilical cord arterial pH, five-minute Apgar scores) that were associated with a potential adverse outcome.ResultsWe assessed 1313 tracings with simultaneous displays of the MHR and FHR in labour. MHRA was present at least once in 721 tracings (55%). Of these tracings, 35 were classified as having one or more episodes that might have led to an adverse outcome (either false positive or false negative), giving an incidence of 2.7% of all women in labour. In 33 tracings, the MHRA masked an abnormal FHR tracing. In two tracings, the MHRA masked a normal FHR, which might have resulted in misinterpretation of the tracing (i.e., false positive), leading to unnecessary intervention.ConclusionThe incidence of MHRA is higher than currently thought, and in more than 2% of women in labour may lead to adverse outcomes. We propose routine use of simultaneous maternal and FHR monitoring for women undergoing EFM, especially during the second stage of labour.     

Prenatal Diagnosis of the Fetal Rhc Genotype From Peripheral Maternal Blood

Objective: To determine the fetal Rhc genotype by using the polymerase chain reaction (PCR) amplification procedure and maternal blood at the different steps of the fetal cell enrichment process.Methods: Maternal peripheral venous blood samples were obtained from 11 pregnant women homozygous for the C antigen before amniocentesis. Three were not alloimmunized and eight were alloimmunized. The fathers were known to be heterozygous or homozygous for the c antigen by serologic testing. The mononuclear cell layer was isolated from maternal blood and flow sorted using monoclonal antibodies to CD36 or CD71 and glycophorin A. This was followed by PCR of the blood, mononuclear cells, and the sorted cells with allele-specific primers to RhCc genes. Gel electrophoresis was performed to predict fetal Rhc genotype. The fetal RhCc genotype was confirmed by serologic and DNA testing.Results: All infants were positive for the Rhc gene. The positive fetal Rhc genotype was determined correctly in three of the 11 maternal blood samples without enrichment, in six of the nine mononuclear cell samples, and in seven of the eight sorted cell samples. The fetal genotype from one sorted sample was predicted to be homozygous C. One infant was determined by serology on cord blood to be negative for the c antigen, but repeated infant DNA amplification was consistent with the c genotype.Conclusion: Noninvasive fetal Rhc genotyping can be determined by PCR amplification of the rare fetal cells in maternal blood. These data reaffirm that enrichment of maternal blood for fetal cells is necessary to improve the sensitivity of the test.     

孕妇外周血及胎盘组织中胎儿有核红细胞出现频率与胎儿生长受限

目的　探讨孕妇外周血及胎盘组织中胎儿有核红细胞 (nucleated red blood cell,NRBC)的出现频率与胎儿生长受限 (fetal growth restriction,FGR)的关系。　方法　对 2 0例孕 2 8～36周 ,年龄 2 1～ 30岁 (包括 9例 FGR)的孕妇外周血进行不连续密度梯度离心 ,对分离后的细胞进行制片 ,显微镜下进行 NRBC计数 ,比较组间差异 ;追随至终止妊娠时 ,对胎盘组织进行切片 ,显微镜下进行 NRBC计数 ,比较组间差异 ;显微操作法获取 5例单个 NRBC行引物延伸预扩增 (PEP)和聚合酶链反应 (PCR) ,验证其胎儿细胞来源。　结果　 9例 FGR妊娠妇女外周血中 NRBC数目从 12个 / 7ml～ 4 0个 / 7ml不等 ,平均为 2 2 .6个 / 7m l。而同孕龄正常妊娠妇女外周血中 NRBC数目从 0个 / 7ml～ 10个 / 7ml不等 ,平均为 5 .4个 / 7ml,两者间差异有极显著性 (P<0 .0 0 1) ;FGR妊娠妇女胎盘绒毛间质血管中 NRBC数目从 2个 / 2 0 HP～ 5个 / 2 0 HP不等 ,平均为 2 .8个 / 2 0 HP。而正常妊娠妇女则从 0个 / 2 0 HP～ 2个 / 2 0 HP不等 ,平均为 0 .6个 / 2 0 HP,两者间差异有显著性 (P<0 .0 5 )。　结论　FGR妊娠妇女其外周血与胎盘组织中 NRBC数目明显升高     

Maternal Fetal Nutrition

Twin pregnancy is one of the highest risk factors in pregnancy. The relationship between sound nutritional practices during a singleton pregnancy and improved maternal, fetal, and infant outcomes has long been demonstrated. But little is known about the nutritional requirements of the mother expecting twins and the needs of her two fetuses. Key areas of the nurse's role with regard to nutritional assessment and intervention for women expecting twins are identified and discussed.     

经母血采集胎儿细胞行产前诊断的最佳时间探讨

目的：探讨利用母血循环中胎儿细胞进行产前诊断的最佳采血时间。方法：对４１例孕龄为６～１４周的妇女连续取血，采用套式聚合酶链反应技术检测人类Ｙ染色体特异的锌指蛋白基因（ＺＦＹ）。结果：１９例妊娠男性胎儿妇女外周血ＺＦＹ随着孕龄的增加，其胎儿单拷贝基因的检出率增高，其中孕６周时检出率为１／１９（５．３％），孕１１周时为１３／１９（６８．４％），而到孕１４周时，则达到１８／１９（９５．０％）；对２２例妊娠女性胎儿妇女外周血进行ＺＦＹ检测时，无一例假阳性结果，这一检测方法在妊娠早期进行胎儿性别鉴定的总准确率达到９７．８％（４０／４１）。结论：利用母血循环中胎儿细胞进行产前诊断的最佳采血时间应在妊娠１４周，同时提示胎儿细胞最早进入母血循环中的时间在不同个体间存在明显的差异。     

Maternal Anxiety in Pregnancy and Fetal Homeostasis

Although it is recognized that pregnant women may be extremely anxious and that anxiety is accompanied by sympathetic nervous system hyperactivity, little clinical consideration has been given to the potential harm to the fetus. A review of the literature, including research on both animal and human pregnancies, reveals what is known about this subject. A section on implications for maternity care follows, including a summary of the possible effects of anxiety during pregnancy, identification of women most at risk from anxiety, and intervention measures.     

The Impact of Maternal Obesity on Maternal and Fetal Health

The increasing rate of maternal obesity provides a major challenge to obstetric practice. Maternal obesity can result in negative outcomes for both women and fetuses. The maternal risks during pregnancy include gestational diabetes and preeclampsia. The fetus is at risk for stillbirth and congenital anomalies. Obesity in pregnancy can also affect health later in life for both mother and child. For women, these risks include heart disease and hypertension. Children have a risk of future obesity and heart disease. Women and their offspring are at increased risk for diabetes. Obstetrician-gynecologists are well positioned to prevent and treat this epidemic.Key words: Obesity, Maternal health, Diabetes, Fetal health, Birth outcomesThe worldwide prevalence of obesity has increased substantially over the past few decades. Economic, technologic, and lifestyle changes have created an abundance of cheap, high-calorie food coupled with decreased required physical activity. We are eating more and moving less. There is evidence for metabolic dysregulation among obese individuals that has been linked with a number of possible environmental factors, including contaminants from modern industry. Obesity is a significant public health concern and is likely to remain so for the foreseeable future. Maternal obesity increases the risk of a number of pregnancy complications, including preeclampsia, gestational diabetes mellitus (GDM), and cesarean delivery (1 Excessive weight gain during pregnancy and postpartum retention of pregnancy weight gain are significant risk factors for later obesity in women.² Additionally, maternal health can have a significant impact on the in utero environment and, thus, on fetal development and the health of the child later in life (3

Table 1

Obstetric Complications in Obese Pregnant Women