Mode of Delivery and the Survival of Macrosomic Infants in the United States, 1995–1999

ABSTRACT: Background: Although increases in perinatal mortality risk associated with fetal macrosomia are well documented, the optimal route of delivery for fetuses with suspected macrosomia remains controversial. The objective of this investigation was to assess the risk of neonatal death among macrosomic infants delivered vaginally compared with those delivered by cesarean section. Methods: Data were derived from the U.S. 1995–1999 Linked Live Birth‐Infant Death Cohort files and term (37–44 wk), single live births to United States resident mothers selected. A proportional hazards model was used to analyze the risk of neonatal death associated with cesarean delivery among 3 categories of macrosomic infants (infants weighing 4,000–4,499 g; 4,500–4,999 g; and 5,000+ g). Results: After controlling for maternal characteristics and complications, the adjusted hazard ratio for neonatal death associated with cesarean delivery among the 3 categories of macrosomic infants was 1.40, 1.30, and 0.85. Conclusions: Although cesarean delivery may reduce the risk of death for the heaviest infants (5,000+ g), the relative benefit of this intervention for macrosomic infants weighing 4,000–4,999 g remains debatable. Thus, policies in support of prophylactic cesarean delivery for suspected fetal macrosomia may need to be reevaluated. (BIRTH 33:4 December 2006)     

再论妊娠期糖尿病与胎儿生长发育

目的 研究妊娠期糖尿病与胎儿生长发育中糖代谢特点的关系。方法 选择妊娠期糖尿病25例（GDM组），正常孕妇20例（对照组），分别测孕妇空腹血糖、糖耐量、C肽、IGF－I、新生儿出生2h内空腹血糖，并依据新生儿出生体重分为大于胎龄儿组（LGA组，≥4000g），适于胎龄儿组（AGA组，2500－3999g)。结果 C肽及新生儿出生2h内空腹血糖GDM组与对照组差异有显著性；糖耐量各时点血糖值餐后2h血糖值LGA和AGA组差异有显著性。结论 血糖始终是影响胎儿生长发育的重要因素，孕妇餐后2h血糖水平与巨大儿的发生呈正相关。     

The Role of Maternal Weight in the Hierarchy of Macrosomia Predictors; Overall Effect of Analysis of Three Prediction Indicators

So far it has not been established which maternal features play the most important role in newborn macrosomia. The aim of this study is to provide assessment of a hierarchy of twenty six (26) maternal characteristics in macrosomia prediction. A Polish prospective cohort of women with singleton pregnancy (N = 912) which was recruited in the years 2015–2016 has been studied. Two analyses were performed: for probability of macrosomia > 4000 g (n = 97) (vs. 755 newborns 2500–4000 g); and for birthweight > 90th percentile (n = 99) (vs. 741 newborns 10–90th percentile). A multiple logistic regression was used (with 95% confidence intervals (CI)). A hierarchy of significance of potential predictors was established after summing up of three prediction indicators (NRI, IDI and AUC) calculated for the basic prediction model (maternal age + parity) extended with one (test) predictor. ‘Net reclassification improvement’ (NRI) focuses on the reclassification table describing the number of women in whom an upward or downward shift in the disease probability value occurred after a new factor had been added, including the results for healthy and ill women. ‘Integrated discrimination improvement’ (IDI) shows the difference between the value of mean change in predicted probability between the group of ill and healthy women when a new factor is added to the model. The area under curve (AUC) is a commonly used indicator. Results. The macrosomia risk was the highest for prior macrosomia (AOR = 7.53, 95%CI: 3.15–18.00, p < 0.001). A few maternal characteristics were associated with more than three times higher macrosomia odds ratios, e.g., maternal obesity and gestational age ≥ 38 weeks. A different hierarchy was shown by the prediction study. Compared to the basic prediction model (AUC = 0.564 (0.501–0.627), p = 0.04), AUC increased most when pre-pregnancy weight (kg) was added to the base model (AUC = 0.706 (0.649–0.764), p < 0.001). The values of IDI and NRI were also the highest for the model with maternal weight (IDI = 0.061 (0.039–0.083), p < 0.001), and (NRI = 0.538 (0.33–0.746), p < 0.001). Adding another factor to the base model was connected with significantly weaker prediction, e.g., for gestational age ≥ 38 weeks (AUC = 0.602 (0.543–0.662), p = 0.001), (IDI = 0.009 (0.004; 0.013), p < 0.001), and (NRI = 0.155 (0.073; 0.237), p < 0.001). After summing up the effects of NRI, IDI and AUC, the probability of macrosomia was most strongly improved (in order) by: pre-pregnancy weight, body mass index (BMI), excessive gestational weight gain (GWG) and BMI ≥ 25 kg/m². Maternal height, prior macrosomia, fetal sex-son, and gestational diabetes mellitus (GDM) occupied an intermediate place in the hierarchy. The main conclusions: newer prediction indicators showed that (among 26 features) excessive pre-pregnancy weight/BMI and excessive GWG played a much more important role in macrosomia prediction than other maternal characteristics. These indicators more strongly highlighted the differences between predictors than the results of commonly used odds ratios.     

近10年新生儿出生体重变化趋势的分析

目的 探讨新生儿出生体重（NBW）的变化趋势及其与剖宫产率之间的关系。方法 回顾性分析上海市普陀区妇婴保健院1989年至1998年10年间NBW的变化,及不同出生体重儿（低体重儿、正常体重儿和巨大儿）孕妇的分娩方式;并对初次产前检查≤20周至足月分娩的产妇,按NBW的不同分为3组,分析孕妇孕期体质指数（BMI）的增加与NBW之间的关系。结果 10年间NBW呈上升趋势,其中巨大儿的发生率明显增加（P＜0.05）、男婴多于女婴（P＜0.005）。随着NBW的增加,剖宫产率明显上升（P＜0.005）。巨大儿的孕妇其孕期BMI的增加与其它各组相比差异有显著性（P＜0.001）。结论 NBW和孕妇孕期BMI的过度增加是导致巨大儿发生率和剖宫产率上升的重要因素。加强孕妇孕期的膳食指导将是控制NBW、降低剖宫产率的有效手段。     

Development of a dietary screening questionnaire to predict excessive weight gain in pregnancy

Excessive gestational weight gain (GWG) is a risk factor for several adverse pregnancy outcomes, including macrosomia. Diet is one of the few modifiable risk factors identified. However, most dietary assessment methods are impractical for use in maternal care. This study evaluated whether a short dietary screening questionnaire could be used as a predictor of excessive GWG in a cohort of Icelandic women. The dietary data were collected in gestational weeks 11–14, using a 40‐item food frequency screening questionnaire. The dietary data were transformed into 13 predefined dietary risk factors for an inadequate diet. Stepwise backward elimination was used to identify a reduced set of factors that best predicted excessive GWG. This set of variables was then used to calculate a combined dietary risk score (range 0–5). Information regarding outcomes, GWG (n = 1,326) and birth weight (n = 1,651), was extracted from maternal hospital records. In total, 36% had excessive GWG (Icelandic criteria), and 5% of infants were macrosomic (≥4,500 g). A high dietary risk score (characterized by a nonvaried diet, nonadequate frequency of consumption of fruits/vegetables, dairy, and whole grain intake, and excessive intake of sugar/artificially sweetened beverages and dairy) was associated with a higher risk of excessive GWG. Women with a high (≥4) versus low (≤2) risk score had higher risk of excessive GWG (relative risk = 1.23, 95% confidence interval, CI [1.002, 1.50]) and higher odds of delivering a macrosomic offspring (odds ratio = 2.20, 95% CI [1.14, 4.25]). The results indicate that asking simple questions about women's dietary intake early in pregnancy could identify women who should be prioritized for further dietary counselling and support.     

Fetal pancreatic Langerhans islets size in pregnancies with metabolic disorders

Objective: Metabolic disorders are a pandemic and increasing health problem. Women of childbearing age may also be affected, thus an abnormal metabolism may interfere with pregnancy short- and long-term outcomes, harming both mother and child. In the context of an abnormal maternal and intrauterine metabolic milieu the development of fetal organs, including pancreas, may be affected.

Aim: To investigate the effects of pregnancy metabolic disorders on the morphology of pancreatic Langerhans islets in human late-third trimester stillborn fetuses.

Methods: Samples from fetal pancreas underwent a quantitative histological evaluation to detect differences between pregnancy with (cases, n?=?9) or without (controls, n?=?6) abnormal metabolism.

Results: Results show that the islets size increases in fetuses from dysmetabolic pregnancies and that this increment is related to both beta-cell hyperplasia and hypertrophy. Moreover, according to pregnancy and fetal metabolic disorders, a threshold of abnormal size of the islets has been identified. Above this threshold the size of fetal pancreatic Langerhans islets should be considered excessively increased.

Conclusion: The study suggests that an accurate fetal pancreas analysis supplies an important tool in stillborn fetus, to discover metabolic disturbances that should be kept in mind and managed in future pregnancies.     

Maternal and neonatal outcomes in pregnancies complicated by gestational diabetes. a nation-wide study

Objective: To estimate the association between gestational diabetes mellitus (GDM) and adverse pregnancy and neonatal outcomes in Denmark.

Methods: A population-based cohort study including all singleton pregnancies in Denmark from 2004 to 2010 (n?=?403?092). Maternal complications during pregnancy and delivery and fetal complications were classified according to the International Classification of Diseases 10th Revision.

Results: The final study population consisted of 398?623 women. Of these, 9014 (2.3%) had GDM. Data were adjusted for maternal age, parity, smoking, gestational age, birth weight, BMI, gender of the fetus and calendar year. The risk of preeclampsia, caesarean section (both planned and emergency) and shoulder dystocia was increased in women with GDM. In the unadjusted analysis, the risk of thrombosis was increased by a factor 2 in the GDM patients, but in the adjusted analysis this association disappeared. Post-partum hemorrhage was similar in the two groups. The GDM women had an increased risk of giving birth to a macrosomic neonate although the unadjusted analysis did not show any difference between the two groups. Low Apgar score was increased in the GDM, but this association disappeared in the adjusted analysis. Stillbirth was comparable in the two groups.

Conclusions: Women with GDM still have increased incidence of obstetric and neonatal complications, which could imply that treatment of women with GDM should be tightened.     

产前超声测量多项指标预测胎儿体重的意义

目的:探讨产前超声测量多项指标预测胎儿体重的方法及其意义.方法:以在某院出生的1560例新生儿作为研究对象,在分娩前3天内超声测量胎儿体重、双顶径、腹围和股骨长,分析胎儿体重和各指标之间的关系.结果:1560例单胎足月胎儿,体重(3320.13±512.13)g,双顶径(92.75±4.29)mm,腹围(343.76±22.27)mm,股骨(71.20±3.37)mm.胎儿体重与双顶径、腹围和股骨之间均有相关性,相关系数r在0.672~0.767,且有统计学意义.多因素分析显示新生儿体重与腹围相关性最大,双顶径次之,股骨长最小.通过受试者工作曲线(ROC)分析,利用胎儿腹围、股骨长和双顶径来判定巨大儿的截断值分别为355.00mm、73.50mm和95.50mm, 灵敏度分别为68.8%、68.8%和62.5%, 特异度分别为77.9%、79.2%和76.6%.结论:分娩前超声测量胎儿腹围、股骨长、双顶径可预测新生儿出生体重,腹围大于355mm、股骨大于73.50mm、双顶径大于95.5mm对预测巨大儿有临床价值.     

肩难产综合预防措施的荟萃分析

目的 探讨肩难产的综合预防措施.方法 计算机检索2014年5月以前的PubMed数据库、美国EBSCO数据库、荷兰医学文摘数据库、Cochrane图书馆数据库,以“shoulder dystocia and prevention”为主题词检索英文文献.对检索到的文献进行质量评价,文献研究类型仅限于随机对照临床试验(RCT)研究;研究对象为经阴道分娩产妇,干预措施包括孕期管理、预防性引产、预防性剖宫产术,预防性肩难产处理.纳入的文献采用RevMan 5.1软件进行荟萃分析,以肩难产发生率作为终点指标.结果 共有16篇英文文献纳入荟萃分析,发表时间为1993-2009年.(1)对妊娠期糖尿病(GDM)孕妇的孕期干预:有2篇文献比较了GDM孕妇的孕期干预(干预组)与不干预(不干预组)对肩难产发生率的影响,结果显示,干预组肩难产发生率显著低于不干预组(OR=0.40,95％ CI为0.21～0.75,P=0.004).(2)对GDM孕妇的孕期严格干预:5篇文献比较了GDM孕妇的孕期严格干预(饮食控制+胰岛素应用;严格干预组)与不严格干预(单纯饮食控制等;不严格干预组)对肩难产发生率的影响,结果显示,严格干预组肩难产发生率显著低于不严格干预组(OR=0.29,95％CI为0.11～ 0.73,P=0.009).(3)非糖尿病孕妇可疑巨大儿者引产:有4篇文献比较了非糖尿病孕妇可疑巨大儿者提前引产(提前引产组)对肩难产发生的影响,结果显示,提前引产组肩难产发生率与对照组比较,差异无统计学意义(OR=0.85,95％CI为0.41～ 1.75,P=0.660).(4)GDM孕妇引产:有2篇文献比较了GDM孕妇提前引产(孕38～ 39周;提前引产组)对肩难产发生的影响,结果显示,提前引产组肩难产发生率与对照组比较,差异有统计学意义(OR=0.18,95％CI为0.03～ 0.97,P=0.050);只与对照组中孕40周以后分娩者比较,提前引产组肩难产发生率显著低于对照组(OR=0.13,95％ CI为0.02～ 0.75,P=0.020).(5)GDM孕妇可疑巨大儿者提前终止妊娠:仅有1篇文献比较了GDM孕妇中可疑巨大儿者提前终止妊娠(提前终止妊娠)对肩难产发生率的影响,结果显示,提前终止妊娠组的肩难产发生率与对照组比较,差异有统计学意义(OR=0.34,95％CI为0.12～ 0.99,P=0.050).(6)产时预防性干预(产时干预组)对肩难产发生率的影响:有2篇文献比较了产时胎头娩出后行预防性干预对肩难产发生率的影响,结果显示,产时干预组肩难产发生率与对照组比较,差异无统计学意义(OR=0.44,95％CI为0.16～ 1.18,P=0.100).结论 对有肩难产高危因素的孕妇适当进行临床措施的干预,可明显降低肩难产的发生率.     

Determinants and outcome of fetal macrosomia in a Nigerian tertiary hospital

Background:

To determine the incidence and risk factors of fetal macrosomia and maternal and perinatal outcome.

Patients and Methods:

This was a 1-year prospective case–control study of singleton pregnancies in a Nigerian tertiary hospital. Only women who gave consent were recruited for the study. The maternal and perinatal outcomes in women who delivered macrosomic infants (birth weight ≥ 4000 g) were compared with the next consecutive delivery of normal birth weight (2500–3999 g) infants.

Results:

The total deliveries for the study period were 2437, of which 135 were macrosomic babies. The incidence of fetal macrosomia was 5.5%. The mean birth weights of macrosomic and nonmacrosomic babies were 4.26 ± 0.29 kg and 3.20 ± 0.38 kg, respectively, P = 0.000. Mothers with macrosomic babies were more likely to be older (P = 0.047), of higher parity (0.001), taller (P = 0.007), and weighed more at delivery (P = 0.000). Previous history of fetal macrosomia (P = 0.000) and maternal diabetes (P = 0.007) were factors strongly associated with the delivery of macrosomic infants. Pregnancies associated with fetal macrosomia had increased duration of labor (P = 0.007), interventional deliveries (P = 0.000), shoulder dystocia, and genital laceration (P = 0.000). There was no significant difference in the incidence of primary postpartum hemorrhage (P = 0.790), birth asphyxia, and perinatal mortality (P = 0.197).

Conclusion:

Fetal macrosomia is associated with maternal and fetal morbidities. The presence of the observed risk factors should elicit the suspicion of a macrosomic fetus and the need for appropriate management to reduce maternal and fetal morbidities.