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Meaning of mean and standard deviation values of newborns’ birthweight in diagnosing fetal intrauterine growth retardation
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- Điều hướng trang này:
- 1.6.2. Use of fetal growth chart in diagnosing newborn large for GA
- Chapter 2: METHODOLOGY
- 2.1.1.2. Exclusion criteria
- 2.1.2.1. For objective 2.1
1.6.1.3. Meaning of mean and standard deviation values of newborns’ birthweight in diagnosing fetal intrauterine growth retardation1.6.1.4. Meaning of correlative values between anthropometric indicesin growth chart to diagnose fetal intrauterine growth retardation1.6.2. Use of fetal growth chart in diagnosing newborn large for GA1.6.2.1. Definition of a newborn large for GA- Risk factors of being born large for GA - Labor dystocia and complications relate to newborn large for GA 1.6.2.2. Meaning of birth weight percentiles diagnosing newborn large for GA Most authors identify large for GA are those birthweight above the 90th percentile by GA. For example, basing on the percentiles of fetal birthweight by GA created by Lubchenco (1963), a newborn with 39 weeks of GA, whose birthweight is over 3700gr, is indentified as an overweight baby while a newborn with 40 weeks of GA is considered to be overweight by GA if his/her birthweight is over 3800gr. An other definition of an large for GA newborn is the baby whose birthweight over the normal birthweight value. In Vietnam, we identify a nulliparous newborn large for GA if he/she is over 3500gr and a multiparous newborn large for GA if he/she is over 4000g. In developed countries, a newborn large for GA if he/she is nulliparous and over 4000gr or mutiparous and over 4500gr.The question is if a fetus, whose birthweight is over normal value, may be identified as abnormal or not? What is the cutoff of abnormal birthweight and can it be used to predict complications of over birthweight newborns? Is the abnormal birthweight merely methematical value or can it cause problems during gestational and labor period? Chapter 2: METHODOLOGY2.1. Study subjects. 2.1.1. For objective 1:2.1.1.1. Selection criteria for the study subjects: Mothers: The subjects were healthy pregnant women, are married Vietnamese men, who admitted to antenatal care department and had a labour at the National and Haiphong Hospital of Obstetrics and Gynaecology, singleton fetus, aged 18-40, GA of these fetus between 28 and 42 weeks. Newborn baby: is their children. 2.1.1.2. Exclusion criteria* Mothers: Did not remmeber their last menstrual cycles and had no ultrasound in the first trimester. Mothers had any chronic diseases or abnormalities of the genital organs these can affect the development of the fetus. * Fetus: abnormal fetus may related to intrauterine growth 2.1.2. For objective 2: The content of objective 2 is to determine the cut-off point for measurements corresponding percentile line does have prognostic value for pregnancy below average and above average (WHO called fetal IUGR and macrosomia) are related to complications at birth and after birth. Thus, the object of study include 2 parts: the object of study for fetal weight below average related complications (IUGR) and fetal weight below average -related complications (macrosomia). 2.1.2.1. For objective 2.1:Selection criteria: The weight newborn was below average included 2 groups: infants after birth-related complications such as asphyxia, hypoglycemia, low blood cancium level, neonatal sepsis, multiple erythrocyte, death (these children were listed by Lubchenco as IUGR). The second group was underweight infants below average but were normal, the sample size is double to group 1. However this 2 parts have the same study design and sample size formula with a sensitivity and specificity are very close , therefor it can be applied to the same sample size.2.1.2.2. For objective 2.2: Selection criteria: The infant weighed were above average related to labour and postpartum complications and newborn weight were above the average and normal is to ensure calculation of sensitivity and specificity effect. 2.2. Time and place of study At 2 hospitals: National Hospital of Obstetrics and Gynaecology and Haiphong hospital during period of time from November 2009 to March 2013. 2.3. Research methodology and data collection process 2.3.1. Study design - Study design for objectve 1: a descriptive study was done to decribe the average value by prospective approach. - Study design for the objetive 2: to assess the value of one method (percentile chart) that can apply on clinical.
Calculation for objective 1:
n: sample size; Z2(1-α/2): express to significance, if α = 0,05 then Z2(1-α/2) =1,96 (sigfinicant level 95%.  : mean value estimate based on previous study= 2596g, S: standard deviation estimates based on results of a previous study. : Approximately permissible variation between the mean values obtained from samples research and of population values, select = 0.01. L: number of layers of gestation (15 classes from 28-42 weeks). Select measuring fetal weight in GA between classes (35 weeks), average weight = 2596g and standard deviation = 200g S, so the number of study subjects was 3418 cases.
2.1.2.3. Sample size for objective 2 (part 1 and 2): Fomular:
Z2(1-α/2): reliability. If choose α = 0,05 then Z2(1-α/2) =1,96 (corresponding to 95% confidence level). p = Sensitivity respectively estimated 87% cut point. q = 1 - p (false positive diagnosis) = 13%. ε: error research: an estimated of 5% (According to Phan Truong Duyet). Then the total number of objects 2.1 was at least 117 cases. 2.3.3. The process of data collection 2.3.3.1. Founded investigation team: - Staff: each team worked at each hospital, a team of four midwives accompanied by the participation and supervision of the princilpe researchers. Trainning for measurements for child on weight, length, head circumference and interview their mothers were needed. - Test for validity: + Each group was tesed on 50 newborns, each person take one measurment, then compared the results between the different measurements. Check measurement tool once a month. 2.3.3.2. Data variable collection: * For mothers:For parent : name, age, address, height, weight, parity. Obstetric medical records related to the development of the child in the uterus, the factors related to the process of labor, method of delivery. * For infants: GA, fetal morphology: fetus do not suffer from birth defects, weight, length, head circumference of the infant. Index of weight-length (ponderal index: PI) = weight (gr) x100/length (cm) 3, the Appgar 1 minute and 5 minutes after birth. Respiratory support after birth: oxygen, ventilation, mechanical ventilation.
GA: counted per week from the first day of the last menstrual period to the date of delivery. GA was calculated according to the ultrasound results in the first trimester associated with GA based on the first day of the last menstrual period and/or characteristics of the infant after birth. Weight: weight infants were measured within the first hour immediately after delivery. Length of the newborn: measured within 1 day after birth by a specific measure. Newborn head circumference: measured within 1 day after birth. Severe preeclampsia: maternal systolic blood pressure ≥ 160mmHg and/or diastolic blood pressure ≥ 110mmHg accompanied by urinary protein > 2 g/l. Respiratory support after birth: oxygen, ventilation, intubation, mechanical ventilation. Lower blood calcium: total calcium < 1.8 mmol/l; Hypoglycaemia: blood glucose < 2.6 mmol/l ; polycythemia: peripheral venous blood hematocrit ≥ 65%; veinous or umbilical venous or artery hematocrit > 63%, red skin. Neonatal infections: bronchitis, pneumonia, respiratory failure, pulmonary nodules X -ray translucent irregular, tracheal culture presented with of bacteria. Necrotizing enterocolitis: vomitting with yelow or green liquid, stool with very smelly. Pathologies related to dystocia due to macrosomia: full dilate cervix but failue of fetal descent. the cervix is full dilation over 60 ' but there is no the fetal descent. Secondary arrest of dilatation or arrest of descent: the sign of prolong labor at labor chart. Vertex slip test is failed: when the cervix is dilated 3cm in the first time labour or 4cm in the second time labour then press the aminotic sack. Failure test is reached when there is presence of fetal distress (bradycardia, late deceleration or various deceleration on monitoring, > 5 uterine contration/10' and /or prolonged > 60 seconds, expression prolonged labor after amniotomy. Mother in normal labour doesn’t affect the their child: mother pushing herself with 15-30 minutes since the head go through the servix, the cervix is full open but the head not go through (provided the normal uterine contractions: frequency of 5 and lasts 50-60 seconds). 2.5. Data analysis t (test ) was used to evaluate the difference between two mean difference, statistical significance is at p < 0.05. A correlation between the two quantities for each function y = f (x) ( y is the anthropometric index, x is the GA) has a correlation when r > 0.5. Calculation of the value distribution to percentile 3, 5, 10, 50, 90, 95, 97 based on the average value was determined.Based on the value of percentile distribution, charts were plotted according to GA fetal development and charting percentile. Sensitivity, specificity and ROC curves was made to determine the cut-off point of measurement related diseases. Cut-off point will be matched with corresponding percentile line does use the percentile lines for diagnosis. 2.6. Ethical consideration The study was done by using anthropometric measurments. The methods does not affect the health of children. Topic was aproved by the council of science and ethics, as well as through the university council and the science of medical ethics hospital, all data were obtained as confidentially. Каталог: images -> ngcuusinh images -> Céng hßa x· héi chñ nghÜa viÖt nam Độc lập tự do hạnh phúc images -> Lúa gạo Việt Nam Giới thiệu images -> Trung Tâm kt tc-đl-cl images -> Số: 105/2008/QĐ-ttg CỘng hòa xã HỘi chủ nghĩa việt nam độc lập Tự do Hạnh phúc images -> ChuyêN ĐỀ ĐẠi số TỔ HỢP, XÁc suất kiến thức cơ bản Đại số tổ hợp images -> BỘ giáo dục và ĐÀo tạo trưỜng đẠi học luật tp. HỒ chí minh dưƠng kim thế nguyên thủ TỤc phá SẢn các tổ chức tín dụng theo pháp luật việt nam images -> Review of Condor, Sun Grid Engine and pbs tải về 0.85 Mb. Chia sẻ với bạn bè của bạn:
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