Distribution of Placental Grading by Gestational Age

Objective: to describe the ultrasonography-based gestation-specific placental grading distribution in a Chinese population.Methods: ultrasonographic examination of placentae was performed in 5,476 normal pregnancies (more than 95% first births) in five obstetric ultrasound laboratories in Central-South China between January 1, 1992 and December 31, 1993. A gestation-specific placental grading distribution was presented and compared with previous studies.Results: the gestational ages of the patients included in this study ranged from 16 to 40 weeks. The gestation-specific distribution of placental grading showed patterns similar to those observed previously, with grade III placentae starting to occur at 32 weeks and increasing to 32.3 percent at 40 weeks of gestation.Conclusions: the occurrence of grade III placentae is too high in preterm and too low in term pregnancies. Ultrasonographic placental grading alone is not a reliable measure of fetal pulmonary maturity.     

胎儿营养不良与小于胎龄儿的区别及临床意义

目的 探讨胎儿营养不良(FM)与小于胎龄儿(SGA)之间的差异及临床意义.方法 对548例单胎足月儿进行临床营养状态评估(CANS),从9个方面迅速地对新生儿进行体表视查评分,总分≤24为FM.结果 40例SGA中21例(占52.5%)为FM,另19例(47.5%)评分＞24;而508例适于胎龄儿中也有13例(占2.8%)为FM.结论 SGA与FM并非同义名称,CANS评分可迅速识别FM,对高危孕母应于孕中期作生化及超声波检测,以便及时发现FM,及时进行营养疗法干预,从而防止FM儿出生.     

Guideline No. 388-Determination of Gestational Age by Ultrasound

ObjectiveTo assist clinicians in assigning gestational age based on ultrasound biometry.OutcomesTo determine whether ultrasound dating provides more accurate gestational age assessment than menstrual dating with or without the use of ultrasound. To provide maternity health care providers and researchers with evidence-based guidelines for the assignment of gestational age. To determine which ultrasound biometric parameters are superior when gestational age is uncertain. To determine whether ultrasound gestational age assessment is cost effective.EvidencePublished literature was retrieved through searches of PubMed or MEDLINE and The Cochrane Library in 2013 using appropriate controlled vocabulary and key words (gestational age, ultrasound biometry, ultrasound dating). Results were restricted to systematic reviews, randomized control trials/controlled clinical trials, and observational studies written in English. There were no date restrictions. Searches were updated on a regular basis and incorporated in the guideline to July 31, 2013. Grey (unpublished) literature was identified through searching the websites of health technology assessment and health technology-related agencies, clinical practice guideline collections, clinical trial registries, and national and international medical specialty societies.ValuesThe quality of evidence in this document was rated using the criteria described in the Report of the Canadian Task Force on Preventive Health Care (Table 1).Benefits, harms, and costsAccurate assignment of gestational age may reduce post-dates labour induction and may improve obstetric care through allowing the optimal timing of necessary interventions and the avoidance of unnecessary ones. More accurate dating allows for optimal performance of prenatal screening tests for aneuploidy. A national algorithm for the assignment of gestational age may reduce practice variations across Canada for clinicians and researchers. Potential harms include the possible reassignment of dates when significant fetal pathology (such as fetal growth restriction or macrosomia) result in a discrepancy between ultrasound biometric and clinical gestational age. Such reassignment may lead to the omission of appropriate—or the performance of inappropriate—fetal interventions.Summary Statements

• 1When performed with quality and precision, ultrasound alone is more accurate than a “certain” menstrual date for determining gestational age in the first and second trimesters (≤ 23 weeks) in spontaneous conceptions, and it is the best method for estimating the delivery date (II).
• 2In the absence of better assessment of gestational age, routine ultrasound in the first or second trimester reduces inductions for post-term pregnancies (I).
• 3Ideally, every pregnant woman should be offered a first-trimester dating ultrasound; however, if the availability of obstetrical ultrasound is limited, it is reasonable to use a second-trimester scan to assess gestational age (I).

Recommendations

• 1First-trimester crown–rump length is the best parameter for determining gestational age and should be used whenever appropriate (I A).
• 2If there is more than one first-trimester scan with a mean sac diameter or crown–rump length measurement, the earliest ultrasound with a crown–rump length equivalent to at least 7 weeks (or 10 mm) should be used to determine the gestational age (III B). Ideally the dating ultrasound is at least 7 weeks or 10 mm of gestation. However, in the absence of timed fertilization, clinical judgement and discretion can be applied should the only early crown–rump length scan be prior to 10 mm and 7 weeks and thus a repeat scan is not mandatory. Factors to consider include the quality of the scan, ultrasound method, and all available clinical information.
• 3Between the 12th and 14th weeks, crown–rump length and biparietal diameter are similar in accuracy. It is recommended that crown-rump length be used up to 84 mm, and the biparietal diameter be used for measurements > 84 mm (II-1 A).
• 4If a second- or third-trimester scan is used to determine gestational age, a combination of multiple biometric parameters (biparietal diameter, head circumference, abdominal circumference, and femur length) should be used to determine gestational age, rather than a single parameter (II-1 A).
• 5When the assignment of gestational age is based on a third-trimester ultrasound, it is difficult to confirm an accurate due date. Follow-up of interval growth is suggested 2 to 3 weeks following the ultrasound (III C).

     

Clinical Epidemiology of Gestational Trophoblastic Disease

The epidemiology of gestational trophoblastic disease (GTD) is not well defined. The rarity of the disease and challenges in data collection limit interpretation of incidence data. Incidence of GTD appears to be influenced by geographic region, with the highest rates occurring in Southeast Asia and Japan. Risk factors for molar pregnancy include extremes of maternal age, reproductive history, and dietary deficiencies. Risk factors for choriocarcinoma include age, ethnicity, history of complete molar pregnancy, and ABO blood group status. With improvements in socioeconomic conditions and diet as well as diagnosis and management of GTD, the incidence of trophoblastic disease is declining worldwide. Future studies should focus on mechanisms by which risk factors influence development and progression of GTD.     

The Relationship Between Gestational Age and Birth-Weight in Twin Pregnancy

Summary: Analysis is made of fetal growth in 563 twin pregnancies. The birth-weight of a twin is affected by the duration of pregnancy and zygosity. Intrauterine growth and weight is the same as a singleton pregnancy up to a gestational age of 32 weeks. After this stage fetal growth slows markedly. The growth curves of both twins are similar with an increasing tendency towards growth retardation in twin 2 after 39 weeks' gestation. Intrauterine growth retardation, as represented by the 10th percentile line, for twin 1 joins l,094g at 31 weeks, l,836g at 36 weeks and 2,428g at 40 weeks' gestation. The corresponding figures for twin 2 are l,131g, l,875g and 2,337g respectively.     

Significance of Birthweight for Gestational Age in Identifying Infants at Risk

If the gestational age and birthweight of all infants are routinely assessed on admission to the newborn nursery, the nurse can identify and bring to the physician's attention infants who are at risk because of prematurity or discrepant weight for gestational age. Treatment then can be started earlier and the prognosis of these infants improved. This paper describes a method of categorizing neonates by weight and gestational age, and physical characteristics such as texture of hair, which can be used as indexes for classification. Weight and age characteristics of intrauterine growth retardation and respiratory distress syndrome are discussed.     

小于胎龄儿血糖的系统监测

目的　探讨小于胎龄儿 (small for gestational age infant,SGA儿 )血糖监测的重点对象及持续时间 ,减少血糖异常造成的损伤。　方法　对 37例出生 (2 .6± 2 .4) h (0 .2 5～ 10 .0 h,中位数 2 .0 h)、非 NICU收治、入院时无输液且未开始喂养的 SGA儿进行为时 (133± 115 ) h (16～ 5 2 4h,中位数 93h)的血糖监测。　结果　监测过程中 2 4例 (6 4% )出现血糖异常 ,其中低血糖 19例(5 1% ) ,高血糖 2例 (5 % ) ,高血糖及低血糖均有发生 3例 (8% )。血糖异常最后发生时间的中位数为10 h,其 95 %可信限为 5～ 5 5 h。 3例反复低血糖发生时间超过 2 40 h。逐步回归分析显示分娩方式与早期血糖水平有关 (P=0 .0 13) ,自然分娩者早期血糖水平高 ;出生体重越低 ,血糖异常最后发生时间越晚 (P<0 .0 1)。另外 ,分析结果显示男婴血糖异常最后发生时间较晚 (P=0 .0 8)。监测期间 ,所有SGA儿未出现血糖异常的相应症状 ,13例予以部分或全静脉营养。　结论　 SGA儿为血糖异常 ,特别是低血糖高危人群 ;对非自然分娩出生的 SGA儿 ,尤应注意早期血糖监测 ;对所有 SGA儿 ,尤其是出生体重及其百分位数低者、男婴应行动态血糖监测 ,并持续至出生后 5 5 h     

The Relationship Between Gestational Age and the Incidence of Classical Caesarean Section

Summary: Improved neonatal survival has led to a rise in the number of Caesarean sections being performed in the presence of extreme prematurity. Many of these operations require an incision in the upper uterine segment with consequent ramifications for the management of any subsequent pregnancy. In this analysis of obstetric patients in a tertiary referral institution over a 9-year period, there was an overall Caesarean section rate of 18%. A classical incision was performed in 1% of all Caesarean sections, but at 24 weeks' gestation, 20% of Caesarean sections were 'classicaľ. This frequency decreased to less than 5% at 30 weeks and less than 1% from 34 weeks' gestation. Most women having a classical Caesarean section at term had either a transverse lie or a major degree of placenta praevia.     

Gestational Age Standardized Nuchal Thickness Values for Estimating Mid-Trimester Down's Syndrome Risk

Objective: Our aim was to develop gestational age standardized indices of fetal nuchal thickening. In addition, we wanted to develop a method for combining nuchal thickness data with maternal age for calculating individual Down's syndrome risk.

Methods: Nuchal thickness was measured prospectively in pregnancies undergoing genetic amniocentesis. A regression equation for expected median nuchal thickness based on the biparietal diameter (BPD) was developed. Nuchal thickness values were expressed as multiples of the median (MoM). Additionally, a new parameter, percentage increase in nuchal thickness (PIN) (measured minus expected nuchal thickness) ×100/expected nuchal thickness, was used. Receiver operator characteristics curves for Down's syndrome detection based on nuchal thickness values expressed as MoM, PIN, and in mm were compared. Logxo transformation of MoM data resulted in a Gaussian distribution, and the Down's syndrome likelihood ratios were calculated based on the heights of the Gaussian curves. Likelihood ratios were also calculated based on PIN values. The screening efficiency of maternal age alone was compared to age plus MoM, and age plus PIN values by multiplying age-related risk by the likelihood ratio corresponding to the given nuchal thickness MoM or PIN values.

Results: There were 3,574 chromosomally normal and 50 Down's syndrome fetuses in the study. Both PIN and MoM values for nuchal thickness were closely correlated (R = 1.00, P < 0.001) and each was poorly correlated with gestational age (R = 0.018, P = 0.28). The Down's syndrome screening efficiency of PIN, MoM, and nuchal thickness values in mm were not significantly different. The addition of nuchal thickness data to maternal age-related risk significantly improved the Down's syndrome screening efficiency: Area under the ROC curve for maternal age risk = 0.58, maternal age + PIN area = 0.79 (P < 0.001 compared to maternal age alone) and for maternal age + MoM = 0.77 (P < 0.005 compared to maternal age alone).

Conclusions: The development of gestational age standardized nuchal thickness indices makes it possible to combine ultrasound and maternal age-related risk to derive individual Down's syndrome odds.     

Prediction of Preeclampsia and Delivery of Small for Gestational Age Babies Based on a Combination of Clinical Risk Factors in High-Risk Women

Objective. To develop clinical risk tools for preeclampsia and small for gestational age (SGA) in high-risk women. Methods. Individual risk scores based on clinical risk factors were calculated using logistic regression and validated in 1687 women with obesity in first pregnancy, chronic hypertension, or previous preeclampsia. Results. The risk of preeclampsia varied from 7% in obese primiparae without hypertension to 30% when previous preeclampsia and chronic hypertension occurred together. A prediction model incorporating these risk factors had a sensitivity of 48 and 89% for preeclampsia delivered <34 weeks' gestation. Conclusion. Multiple clinical risk factors increase the risk of preeclampsia and SGA.     

小于胎龄儿脑发育的随访观察

目的　探讨小于胎龄儿 (SGA)出生时脑发育受影响的程度和出生后脑发育的情况 ,为有脑发育异常的 SGA进行早期干预提供依据。　方法　运用颅脑超声对 SGA的小脑进行冠状位和矢状位小脑面积、周长、纵横径及大脑半球宽度的测量 ,并与适于胎龄儿 (AGA)进行比较分析。　结果　婴儿出生时小脑面积、周长、横径及纵径与其胎龄和出生体重存在较好的相关关系 ,尤以小脑面积和周长与其胎龄和出生体重相关较好 ;大脑半球宽度也与婴儿出生体重存在较好的相关关系。出生时 SGA的脑发育落后于 AGA,出生后 SGA的脑生长速度与 AGA相似 ,但随访至 12个月时 SGA脑发育仍落后于 AGA ,SGA其他脑的异常发生率也较 AGA高。　结论　 SGA不仅在宫内脑的发育受到影响 ,而且可影响到生后脑和神经系统发育 ,故应加强围产期保健 ,制订早期干预计划 ,做好优生工作。     

妊娠滋养细胞肿瘤46例临床分析

目的:分析妊娠滋养细胞肿瘤的临床特点及诊治经验,探讨其临床各期的治疗。方法:收集我院2000年1月至2007年6月收治的妊娠滋养细胞肿瘤46例患者的临床资料,分析其病史特点、发病规律、经化疗或化疗联合手术治疗后的临床转归。结果:46例中放弃治疗2例,44例患者经化疗或化疗结合手术治疗后完全恢复。其中绒毛膜癌11例,完全恢复11例,治愈7例,治愈率63.64%;侵蚀性葡萄胎33例,完全恢复33例,治愈22例,治愈率66.67%。结论:化疗是妊娠滋养细胞肿瘤主要的治疗方法。对有转移瘤破裂出血、不能确定诊断或对化疗耐药的患者,配合适当的手术治疗,疗效更佳。     

Impact of Gestational Weight Gain on Cesarean Delivery Risk,Perinatal Birth Weight and Gestational Age in Women with Normal Pre-pregnancy BMI

Background

Gestational weight gain (GWG) proportional to body mass index before pregnancy is one of the factors on maternal and neonatal outcomes. The aim of the current study was to assess association between GWG, and cesarean section, birth weight and gestational age at birth in women with normal BMI prior to pregnancy.

Methods

This was a cross-sectional study carried out in 103 hospitals in Tehran, the capital of Iran, from July 6 to 21, 2015. The data were extracted by 103 trained midwives. Finally, 2394 pregnant women with normal BMI before pregnancy and singleton birth were examined. GWG was categorized based on Institute of Medicine (IOM) recommendations.

Results

Prevalence of low birth weight (LBW) was 5.41% and prevalence of macrosomia was 2.18%. The prevalence of LBW in women with GWG less than the weight gain recommended by IOM was 2.13 times [95% confidence interval (CI) 1.13–4.02, P = 0.019] more than in women with GWG equal to the weight gain recommended by IOM. There was no statistically significant difference in the prevalence of LBW between women with GWG more than recommended weight gain by IOM and women with GWG equal to the weight gain recommended by IOM (OR = 1.21, 95% CI 0.61–2.38, P = 0.580).

Conclusion

After controlling for confounding variables, the prevalence of cesarean section and preterm birth had no significant difference at various levels of GWG. Accordingly, the prevalence of LBW among women with GWG less than the recommended weight gain by IOM was significantly 2.13 more than that among women with GWG equal to the recommended weight gain by IOM.

     

Birth Weight by Gestational Age for Albertan Liveborn Infants, 1985 Through 1998

Objectives: (1) To provide percentile tables and graphs of birth weight by gestational age and by gender, for singleton and twin liveborn neonates. (2) To determine changes in birth weight relative to gestational age over the study period.Methods: Data on 556,775 singletons and 12,125 twins, born alive in Alberta from 1985 through 1998, were obtained from Alberta Registries — Vital Statistics. Mean birth weights for individual and grouped years were compared by independent two-tailed t-tests. Linear trends in birth weight over the 14-year period were obtained using one-way analyses of variance.Results: Four tables and corresponding graphs showing birth weight for gestational age by gender for 21 through 44 completed weeks gestation provide data for the 1st to 99th percentile. Changes in birth weight for the combined gestational ages included an increase for singletons (male, F 17.6, p < 0.001; female, F 53.3, p < 0.001), and a decrease for female twins (F 5.8, 0.004). The increase for singletons was seen at 38 through 42 weeks gestation for both genders. No change occurred under 38 weeks except in singleton females of 33 to 35 weeks with a decrease in birth weight observed from 2636 ± 539 g, 1985 to 2576 ± 479 g, 1998; t 2.5, p = 0.002.Conclusions: The graphs and tables established in this study represent a specific geographic area and population. They may be relevant as a reference for other geographic regions and populations. The clinical significance of the observed increased birth weight among term, but not preterm newborns, requires critical evaluation.