孕妇体质量及其他因素与分娩巨大儿的相关性研究

目的:探讨孕妇孕前和孕期体质量及有关因素与分娩巨大儿的相关性,为其预防提供指导。方法:选择2013年1月1日至2014年12月31日在四川大学华西第二医院住院分娩符合纳入标准的孕产妇10044例,其中分娩巨大儿466例,非巨大儿9578例。采用Logistics回归分析孕妇体质量及其他因素(妊娠期糖尿病、分娩巨大儿史、多胎妊娠等)与分娩巨大儿的相关性及不同BMI分类与分娩巨大儿的相关性。结果:(1)孕前BMI、孕期总体质量增长、妊娠期糖尿病及既往分娩过巨大儿是分娩巨大儿的独立危险因素(P0.05);多胎妊娠是分娩巨大儿的保护因素(P0.05)。(2)通过BMI分层后,对于孕前BMI正常者,孕期体质量增长过少和多胎妊娠是分娩巨大儿的保护因素(P0.05);孕期总体质量增长、孕期体质量增长过多、有巨大儿分娩史是分娩巨大儿的独立危险因素(P0.05)。对于孕前体质量过轻者,孕期总体质量增长和孕期体质量增长过多是分娩巨大儿独立危险因素(P0.05)。对于孕前超重的孕妇,孕期总体质量增长和妊娠期糖尿病是分娩巨大儿独立危险因素(P0.05)。结论:孕前BMI过高、孕期体质量增长过多、发生妊娠期糖尿病及既往分娩巨大儿史均可使再次妊娠发生巨大儿的风险明显增高;孕前不同BMI孕妇其分娩巨大儿的危险因素有不同,孕期体质量增长过多可能增加孕前偏瘦和体质量正常孕妇巨大儿的发生风险。     

北京密云区地区孕妇孕前体质量指数、孕期体重增加的分布情况

目的 分析北京密云区地区孕妇孕前体质量指数(BMI)、孕期体重增加的分布情况。方法 选取密云区医院定期产检并分娩的孕妇共2553例,对其临床资料进行回顾性分析。分析孕前BMI、孕期体重增加的分布情况。结果 不同文化程度、职业类型、户口类型及年龄段的孕前BMI、孕期体重增加比较,差异有统计学意义(P<0.05)。孕期体重增加数量随着孕前BMI指数的增加而减少。结论 影响北京密云区地区孕妇的孕前BMI及孕期体重增加的因素较多,应结合孕妇的实际情况制定对应的保健管理方案,避免发生不良妊娠事件。     

双胎妊娠孕期体质量增长与妊娠结局关系的研究

目的:探讨孕前不同体质量指数(BMI)的双胎孕妇孕期体质量增长的适宜值,及其与妊娠结局的关系。方法:回顾性分析2018年1月至2020年12月在桂林医学院附属医院产科住院分娩的313例双胎孕妇,按照中国肥胖问题研究专题组提出的判断标准,按孕前BMI将调查对象划分为4组：<18.5 kg/m~2为低体质量组(10例),18.5～24.0 kg/m~2为正常体质量组(192例),24.0～28.0 kg/m~2为超重组(93例),≥28.0 kg/m~2为肥胖组(18例)。按照IOM推荐的双胎足月孕期增重范围,分为增重不足组(120例)、增重适宜组(153例)和增重过多组(40例),研究孕期增重与母体并发症及新生儿出生结局的关系。选择孕周≥37周且活产双胎新生儿平均出生体质量≥2500 g的孕妇共计131例,计算不同BMI双胎孕妇孕期增重的P25～P75,确定孕期体质量增长的适宜范围。采用(印)χ(正)~2检验和多因素Logistic回归分析方法对数据进行统计学分析。结果:(1)与孕前正常体质量组相比,孕前超重组及肥胖组均减少了新生儿平均出生体质量<2500 g的风险[超重组((印)OR(正) 0.551,95%CI 0.334～0.909),肥胖组((印)OR(正) 0.321,95%CI 0.115～0.891)],孕前超重组出现新生儿窒息的风险减少((印)OR(正) 0.353,95%CI 0.151～0.826),但孕前肥胖可增加妊娠期糖尿病((印)OR(正) 3.914,95%CI 1.443～10.618)及子痫前期((印)OR(正) 5.147,95%CI 1.715～15.451)的风险,差异均有统计学意义((印)P(正)<0.05)。(2)与孕期增重适宜组相比,孕期增重不足增加早产((印)OR(正) 3.297,95%CI 2.000～5.433)和至少有1个为小于胎龄儿((印)OR(正) 2.732,95%CI 1.648～4.530)及新生儿平均出生体质量<2500 g((印)OR(正) 3.922,95%CI 2.319～6.635)的风险,但是可降低剖宫产风险((印)OR(正) 0.407,95%CI 0.217～0.765);与孕期增重适宜组相比,孕期增重过多则增加妊娠期糖尿病((印)OR(正) 2.558,95%CI 1.254～5.219)及子痫前期((印)OR(正) 3.429,95%CI 1.475～7.970)的风险,差异有统计学意义((印)P(正)<0.05)。(3)孕周≥37周分娩,且新生儿平均出生体质量≥2500 g的131例孕妇,孕期总增重P25～P75范围分别为：孕前低体质量为15.50～18.75 kg,正常体质量为12.00～20.00 kg,超重为10.75～19.50 kg,肥胖为10.00～16.50 kg,均低于IOM推荐范围。结论:双胎妊娠孕妇孕期体质量增长与其母婴结局密切相关,应对双胎妊娠孕妇孕期体质量管理加以指导,降低不良妊娠结局的发生风险。     

妊娠期糖尿病妇女孕期体质量增加与产后1年体质量滞留及新生儿出生质量的相关性分析

目的 探讨妊娠期糖尿病（GDM）妇女孕期体质量增加（GWG）与产后1年体质量滞留及新生儿出生体质量的关系。方法 选取于本院妇产科进行产检、分娩并在产后1年返院随诊的GDM妇女116例,根据GWG情况将其分为GWG不足组、GWG适宜组、GWG过多组,比较三组的各项临床指标,并采用Spearman相关性分析,分析GWG、产后滞留体质量与其他临床指标的相关性。结果 不同GWG组妇女的年龄、孕次、孕周、产后1年BMI、产后1年体质量、母乳喂养率、剖宫产率比较,差异无统计学意义（P>0.05）;不同组GWG孕妇的孕前体质量指数（BMI）、产后1年滞留体质量、新生儿出生体质量比较,差异有统计学意义（P<0.05）。Spearman相关性分析显示：GWG与GDM妇女产后1年滞留体质量及新生儿出生体质量呈正相关,与孕前BMI呈负相关（P<0.05）,产后滞留体质量与GWG及产后1年BMI呈正相关（P<0.05）。结论 本研究GDM妇女产后1年体质量滞留属中等水平,其GWG与产后1年体质量滞留及新生儿出生体质量呈正相关,与孕前BMI呈负相关。对GDM妇女进行健康宣教、控制GWG在...     

妊娠期高血压、子痫前期及子痫与孕前和孕期体质量及其他因素的相关性研究

目的:探讨妊娠期高血压、子痫前期及子痫与孕前体质量指数(BMI)和孕期体质量增长及其他因素的相关性。方法:本研究纳入2013年1月1日至2014年12月31日在四川大学华西第二医院住院分娩的孕妇共10422例,其中患病组(患妊娠期高血压、子痫前期及子痫)349例,未患病组(未患妊娠期高血压、子痫前期及子痫)10073例。采用Logistics回归分析孕前、孕期体质量及其他因素与妊娠期高血压、子痫前期及子痫的相关性及不同BMI分类与其的相关性。结果:Logistics回归分析示,对于所有孕妇,年龄、孕前BMI过高(包括孕前超重、孕前肥胖)、多胎妊娠、辅助生殖技术受孕、慢性高血压及妊娠期高血压疾病史是妊娠期高血压、子痫及子痫前期的独立危险因素,孕前偏瘦为其保护性因素。通过BMI分层以后,对于孕前BMI正常的孕妇,年龄、BMI、孕期总体质量增长、多胎妊娠、辅助生殖技术、慢性高血压、妊娠期高血压疾病史是3种疾病的独立危险因素;对于孕前超重的孕妇,其危险因素只包括孕前BMI、辅助生殖技术受孕和慢性高血压。结论:孕前BMI过高、多胎妊娠、辅助生殖技术受孕、妊娠期高血压疾病史使妊娠期高血压、子痫及子痫前期的发生风险明显增加;孕前BMI、辅助生殖技术受孕和慢性高血压可能增加孕前体质量正常和超重孕妇妊娠期高血压、子痫及子痫前期的发生风险;孕期体质量增长与妊娠期高血压、子痫及子痫前期的发生关系不明显。     

580例低出生体质量儿的临床分析

目的:了解低出生体质量儿的发生率;低出生体质量儿发生的高危因素、并发症及其转归,探讨针对性的干预措施,减少低出生体质量儿的发生,降低死亡率。方法:对2009年及2010年二年内在本院出生的低出生体质量儿分二组对其病因、并发症及其转归情况进行汇总、分析及随访。结果:低出生体质量儿发生率为3.03%;其中小于胎龄儿占39.7%,早产儿占60.3%。早产低出生体重儿的前4位高危因素分别为胎膜早破、双胎、妊娠期高血压、母亲贫血。早产低出生体重儿的并发症主要是呼吸困难、病理性黄疸、感染和低血糖。足月小样儿组的前4位高危因素分别为孕期感染、阴道流血史、母亲贫血、双胎。足月小样儿组的并发症主要是感染、病理性黄疸。足月小样儿的转院率为3.9%。死亡率为0.4%,早产儿组的转院率达38.3%;死亡率达4%,明显高于足月小样儿组。结论:提高产检率,及时发现并治疗母亲原发病包括感染、高血压、贫血,尽快纠正缺氧等是减少低出生体质量儿的关键。足月小样儿和早产低出生体质量儿在并发症和转归方面有很大的不同,管理上要有不同侧重点来改善预后。     

我国孕妇身高、妊娠前体质量及体质指数的分布情况

【Abstract】?Objective?To compare the pregnancy outcomes of luteal support protocols by methods of endometrium preparation in frozen-thawed embryo transfer cycles. Methods?The retrospective study included the frozen-thawed embryo transfer cycles using vaginal micronized progesterone for luteal support in Sun Yat-sen Memorial Hospital of Sun Yat-sen University from January 2017 to December 2017, including 437 patients in the natural cycle group and 416 patients in the hormone replacement cycle group. According to different luteal support programs, they were divided into four groups: ① Group A: Progesterone soft capsule 400 mg/d; ② Group B: Progesterone soft capsule 400 mg/d+dydrogesterone 20 mg/d; ③ Group C: Progesterone soft capsule 600 mg/d; ④ Group D: Progesterone soft capsule 600 mg/ D+dydrogesterone 20 mg/ D. Different endometrial preparation regimens, luteal support dosages and pregnancy outcomes were compared. Results?①There was no significant difference in the clinical pregnancy rate, abortion rate and live birth rate among different luteal support schemes in the natural cycle group (P>0.05).② The clinical pregnancy rate in group C was lower than that in group D (35.50%, 51.30%, P=0.008). ③ In group C of hormone replacement cycle, the miscarriage rate of patients <35 years old was lower than those ≥35 years old (7.14%, 36.80%, P=0.004). In group C, the clinical pregnancy rate of patients <35 years of age in the hormone replacement cycle group was lower than that in the natural cycle group (38.90%, 68.30%, P=0.002). Conclusion?Enhancing luteal support in artificial cycles would improve the pregnancy outcomes of frozen-thawed cycles.     

我国孕妇身高、妊娠前体质量及体质指数的分布情况

目的 了解我国孕妇身高、妊娠前体质量及体质指数（body mass index, BMI）的分布情况,为我国妇幼保健工作提供依据。方法 中国孕产妇队列研究·协和项目（the Chinese Pregnant Women Cohort StudyPeking Union Medical College, CPWCS-PUMC）于2017年7月至2018年7月招募7 976名早孕期孕妇,采用手机电子问卷收集信息,剔除逻辑错误和填写无效的数据,最终7 802名纳入分析。结果 南北地区孕妇平均身高分别为（159.60±5.02）cm和（162.01±5.19）cm,东中西地区孕妇平均身高分别为（161.35±5.22）cm、（161.31±5.12）cm和（160.41±5.36）cm,且差异均有统计学意义（P <0.05）,但妊娠前BMI在不同地区分布比较,差异均无统计学意义（P>0.05）;身高在民族和户口类型方面分布比较,差异均有统计学意义（P <0.05）。妊娠前体质量在汉族和其他民族分别为（59.13±11.92）kg和（58.78±12.22）kg,两者比较,差异...     

正常妊娠结局的单胎妊娠孕妇体质量增长模式

目的:了解妊娠期规律产前检查未发生不良结局的单胎孕妇妊娠期体质量增长模式。方法:采用回顾性研究,纳入2013年1月至2014年12月妊娠满37周但不超过42周在四川大学华西第二医院住院分娩的孕产妇,采集包括人口学资料、既往疾病史、家族史、孕产史、身高、妊娠前或建卡时体质量及体质量指数(BMI)、妊娠期间每次产前检查时体质量、分娩前体质量等指标。结果:共纳入4053例孕妇,妊娠前BMI正常(18.5~24 kg/m^2)的孕妇,妊娠16周体质量增长平均值为2.45±1.43 kg,妊娠40周体质量增长平均值为15.53±3.59 kg;妊娠前偏瘦(BMI<18.5 kg/m^2)的孕妇,妊娠16周体质量增长平均值为2.57±1.34 kg,妊娠40周体质量增长平均值为16.01±3.42 kg;妊娠前BMI超重(24~28 kg/m^2)的孕妇,妊娠16周体质量增长平均值为2.39±1.44 kg,妊娠40周体质量增长平均值为14.11±3.86 kg;妊娠前肥胖(BMI≥28 kg/m^2)的孕妇,妊娠16周体质量增长平均值为2.17±0.74 kg,妊娠39周体质量增长平均值为12.27±4.07 kg。结论:我院妊娠前BMI正常、偏瘦、超重和肥胖的孕妇适宜的妊娠期体质量增长范围分别为15.53±3.59 kg、16.01±3.42 kg、14.11±3.86 kg和12.27±4.07 kg。     

妊娠期糖尿病患者分娩巨大儿的危险因素分析

目的 探讨妊娠期糖尿病(GDM)患者分娩巨大儿的危险因素,为预防巨大儿的发生提供科学依据。方法 选取669例分娩的GDM患者,根据新生儿体重分为巨大儿组(100例)与非巨大儿组(569例)。回顾性分析患者的临床资料,采用多因素Logistic回归分析GDM患者分娩巨大儿发生的危险因素。结果 两组患者的孕前体重、分娩孕周、胎儿体重、口服葡萄糖耐量试验(OGTT)、糖化血红蛋白(HbA1c)、分娩方式、孕前体质量指数(BMI)、孕期体重增长比较,差异均有统计学意义(P<0.05)。多因素logistic回归分析结果显示孕前超重、肥胖、孕期增重过多、孕期HbA1c≥5.5%是分娩巨大儿的危险因素(P<0.05)。结论 GDM患者孕前超重肥胖、孕期体重增长过多及HbA1c控制不理想均可增加分娩巨大儿的风险,临床中应采取针对性的预防措施以降低巨大儿发生率。     

双胎妊娠孕期不同阶段体质量增长速度与母婴结局的关系

目的:分析双胎妊娠孕期不同阶段体质量增长情况与母婴结局的关系。方法:对2013年1月至2015年10月在上海交通大学医学院附属国际和平妇幼保健院住院分娩的472例双胎妊娠产妇的临床资料进行回顾性分析,比较不同孕前BMI孕妇孕期体质量增长情况,在校正年龄和孕前BMI后,使用二元Logistic回归分析孕期不同阶段体质量增长速度与孕期并发症、早产、胎膜早破和新生儿出生体质量的关系。结果:(1)孕早中期平均体质量增长速度0.41±0.15 kg/w,孕晚期平均体质量增长速度0.64±0.30 kg/w,整个孕期平均体质量增长速度0.49±0.15 kg/w。(2)孕晚期和整个孕期体质量增长过快是妊娠期高血压疾病和发生早产的高危因素(P0.05),孕早中期、孕晚期及整个孕期体质量增长过快是发生胎膜早破的高危因素(P0.05),孕早中期及整个孕期的体质量增长过慢是新生儿低出生体质量的高危因素(P0.05)。(3)在校正年龄、孕前BMI、孕周等因素后,孕期体质量每增加1 kg,双胎出生体质量之和增加25.21 g(P0.001);孕早中期每增加1 kg,双胎出生体质量之和增加30.89 g(P0.001);孕晚期每增加1 kg,双胎出生体质量之和增加21.46 g(P=0.001)。结论:双胎妊娠孕期体质量增长与母婴不良结局密切相关,妊娠不同阶段的体质量增长速度对母婴结局有一定的预测价值,应进一步探讨适合中国人群的双胎妊娠孕期体质量增长适宜范围。     

Effect of Body Mass Index on Pregnancy Outcomes in Nulliparous Women Delivering Singleton Babies: Observational Study

Objective

To find out the effect of increasing body mass index (BMI) on pregnancy outcomes in nulliparous women delivering singleton babies.

Method

This was a hospital-based observation study, based on 300 nulliparous women delivering singleton babies in June 2009—Sept. 2010. Women were categorized into three groups. Underweight (BMI < 20 kg/m²), normal (BMI 20–24.9 kg/m²), overweight (BMI 25–29.9 kg/m²), and obese (BMI > 30 kg/m²) obstetric and perinatal outcomes were compared by univariate and multivariate analysis.

Results

Maximum patients who underwent LSCS were having BMI > 30 kg/m² [OR 9.558 (95 % CI 5.82–17.27)]. As compared to women of normal BMI (20–24.9 kg/m²), morbidly obese women faced the higher risk of PIH [OR 8.045 (95 % CI 3.875–16.781)]. Obese women were more likely to have post partum hemorrhage [OR 5.11 (95 % CI 1.76–14.79)] compared with women of normal BMI. Birth weight <2,500 g was more common in women with BMI < 25 kg/m² (21.21 %), while highest incidence of birth weight >4,000 g (14.29 %) is seen in women of the obese group.

Conclusions

Increasing BMI is associated with increased incidence of cesarean delivery, PIH, post partum hemorrhage, and macrosomic babies.     

Gestational weight gain and glycemic control in GDM patients with positive genital culture

ObjectiveGestational diabetes mellitus (GDM) is related to many complications of pregnancy. The aim of the study was the assessment of cervical colonization in GDM patients and its correlation with inappropriate glycaemic control and gestational weight gain (GWG).Materials and methodsThe study included 483 women with GDM in a singleton pregnancy who delivered at term. Cervical smears samples were collected >35th week of gestation and cultured for aerobic and aerobic bacteria, and fungi. The patients were divided into two groups on the basis of cervical culture test results: women with negative and positive cervical culture results. Gestational weight gain was estimated in both groups as inadequate, adequate or excessive based on pre-gestational body mass index (BMI) according to the Institute of Medicine (IOM) guidelines. GWG and need of insulin therapy were used as an indicator of complying with dietary recommendations.ResultsPatients with positive cervical culture results more frequently had pre-pregnancy BMI >35kg/m2 (4.9% vs 9.5%, p = 0.0508) than patients who had negative cervical culture results. One third (32.1%) of patients had one, and 9.3% had at least two microorganisms in their genital tracts. The most frequent bacteria species isolated was Streptococcus agalactiae (20.1%). Fungi were present in 14.1% of the cervical cultures. Patients with GDM with inadequate GWG more often had genital tract's colonization with Enterococcus spp. (6.83% vs. 1.19% vs. 1.83%, in group with inadequate GWG vs. adequate GWG vs. excessive GWG respectively p = 0.007).ConclusionInsulin therapy in GDM patients was not correlated with the presence of microorganisms in genital tracts. Inadequate GWG in GDM may be linked to genital tract colonization with Enteroccocus spp. Genital colonization during pregnancy among patients with GDM is more often among patients’ with pre-pregnancy BMI >35 kg/m².     

Effects of gestational weight gain and body mass index on obstetric outcome in Sweden.

OBJECTIVE: The objective of this study was to estimate the effects of low and high gestational weight gain, in different maternal Body Mass Index (BMI) classes, on obstetric and neonatal outcomes. METHOD: A prospective population-based cohort study of 245,526 singleton term pregnancies. Women were grouped in five categories of BMI and in three gestational weight gain categories; < 8 kg (low weight gain), 8-16 kg and >16 kg (high weight gain). Obstetric and neonatal outcomes were evaluated after adjustments for maternal age, parity, smoking, year of birth. RESULT: Obese women with low gestational weight gain had a decreased risk for the following outcomes (adjusted odds ratio; 95% confidence interval): preeclampsia (0.52; 0.42-0.62), cesarean section (0.81; 0.73-0.90), instrumental delivery (0.75; 0.63-0.88), and LGA births (0.66; 0.59-0.75). There was a 2-fold increased risk for preeclampsia and LGA infants among average and overweight women with excessive weight gain. High gestational weight gain increased the risk for cesarean delivery in all maternal BMI classes. CONCLUSION: The effects of high or low gestational weight gain differ depending on maternal BMI and the outcome variable studied. Obese women may benefit from a low weight gain during pregnancy.     

Pre-pregnant body mass index, weight gain and the risk of delivering large babies among non-diabetic mothers.

OBJECTIVE: Pre-pregnancy overweight and excess weight gain during pregnancy have each been associated with an increased risk of delivering large babies. However, previous studies have focused on the separate effects of these two indices of weight in diabetic women. METHOD: This study analyzed both separate and combined effects of pre-pregnant body mass index and weight gain in relation to macrosomia (> or =4000 g) in offspring among 815 non-diabetic women, using data collected from a retrospective study. RESULT: Compared to mothers with normal pre-pregnancy BMI and pregnancy weight gain, risk of macrosomia in offspring was significantly elevated only in overweight women with excess weight gain (adjusted OR=2.6, 95% CI [1.2,5.4]) but not among normal weight mothers with excess gain (adjusted OR=1.1, 95% CI [0.5,2.4]) or overweight mothers with normal or low gain (adjusted OR=1.1, 95% CI [0.4,3.1]). CONCLUSION: Given the complications that are associated with delivering large babies, overweight women may benefit from not gaining excess weight in pregnancy.     

Evaluating Body Mass Index–Specific Trimester Weight Gain Recommendations: Differences Between Black and White Women

Introduction: We compared the gestational weight gains of black and white women with the 2009 Institute of Medicine (IOM) recommendations to better understand the potential for successful implementation of these guidelines in clinical settings. Methods: Prenatal and birth data for 2760 women aged 18 to 40 years with term singleton births from 2004 through 2007 were abstracted. We examined race differences in mean trimester weight gains with adjusted linear regression and compared race differences in the distribution of women who met the IOM recommendations with chi‐square analyses. We stratified all analyses by prepregnancy body mass index. Results: Among normal‐weight and obese women, black women gained less weight than white women in the first and second trimesters. Overweight black women gained significantly less than white women in all trimesters. For both races in all body mass index categories, a minority of women (range 9.9%‐32.4%) met the IOM recommended gains for the second and third trimesters. For normal‐weight, overweight, and obese black and white women, 49% to 80% exceeded the recommended gains in the third trimester, with higher rates of excessive gain for white women. Discussion: Less than half of the sample gained within the IOM recommended weight gain ranges in all body mass index groups and in all trimesters. The risk of excessive gain was higher for white women. For both races, excessive weight gain began by the second trimester, suggesting that counseling about the importance of weight gain during pregnancy should begin earlier, in the first trimester or prior to conception.     

Evaluation of the ability of a Latin-American gestational weight curve to predict adverse pregnancy outcomes

Objective

To assess the accuracy of a Latin-American curve used to predict adverse pregnancy outcomes such as low birth weight (LBW), small for gestational age (SGA), large for gestational age (LGA).

Methods

More than 23 000 body mass index (BMI) measurements from 4540 pregnant women participating in a prospective cohort study conducted in 6 Brazilian capitals were analyzed in their relationship to LBW, SGA, LGA, and macrosomia. Analyses were based on receiver operating characteristic curves and models for repeated measures.

Results

The areas under the curve were less than 0.70 for all outcomes, with low sensitivity and specificity for pregestational BMI (0.54-0.61) and BMI at the last prenatal visit (0.63-0.68). The longitudinal model showed a mean weekly BMI gain of 0.16.

Conclusion

The Latin-American curve is inadequate to predict LBW, SGA, and LGA suggesting the need to develop a new approach for the nutritional monitoring of pregnant women.     

Total gestational weight change and rate of change in pregnant Taiwanese women

Objective: The purpose of this study was to estimate and compare total gestational weight gain (GWG) and the trimester-specific mean rate of GWG based on pre-pregnancy body mass index (BMI) as recommended by the Institute of Medicine (IOM).Materials and methods: The medical records of 470 participants who had received antenatal care at medical teaching hospitals in northern Taiwan and who delivered after 37 weeks of pregnancy were analyzed.