Accurate Estimation Of Gestational Age Research Articles

Fetal size and growth

Prior to the introduction of ultrasound, Nägele's rule was the primary method for determining gestational age. Ultrasound has enabled a more accurate estimation of gestational age, allowing for improved detection of the fetus who is small for gestational age and reducing the number of women who are diagnosed as being overdue. The latest biometry charts that can be used for assessment of growth and dating are reviewed. It has long been recognized that a small or growth-retarded fetus has much greater short-term morbidity and mortality compared with its normal counterpart. More recently, the long-term sequelae of this condition are being recognized, illuminating the importance of the prevention and prediction of pregnancies with fetal growth problems. By focusing on better education and nutrition to prevent pregnancies at risk of becoming growth retarded and by using ultrasound to predict and manage these cases, we can improve the outcome for this group of patients.

Dating through pregnancy: a measure of growing up.

The accurate estimation of gestational age is an essential part of pregnancy management, since the consequences of erroneous dating carry increased risks of perinatal morbidity and mortality. Ultrasonography offers a unique opportunity to objectively measure quantitative changes in growth increments of various fetal structures, as well as qualitative changes occurring near term which are indicative of fetal maturity. Therefore, dating through pregnancy is possible by the use of various parameters such as the crown-rump length, the trunk circumference, and the biparietal diameter in the first trimester; the biparietal diameter, the cerebellum, orbital distance, clavicular length, lengths of the long bones of the upper and lower extremities, and the foot length in the second and third trimesters; and the indices of maturity in the late third trimester such as colonic grading and epiphyseal ossification centers of the long bones of the upper and lower extremities. Using a combination of fetal biometry and maturity indices permit dating through pregnancy as a measure of growing up.

An analysis of the decisions in the management of premature rupture of the membranes.

The management of preterm PROM is a complex problem best approached as a number of simple problems to be solved simultaneously. As new information surfaces, the decisions presented in this article can be reevaluated and a new protocol similar to that in Figure 1 developed. On admission of the patient a fetal monitor is placed and intravenous hydration begun. A complete history and physical examination allow accurate estimation of gestational age and diagnosis of ruptured membranes. Any contraindications to tocolysis can be uncovered at this time. If the patient is a candidate for tocolysis, if there are no signs of chorioamnionitis, if there is no fetal distress, and if no contraindications are occurring, then tocolysis may begin. Betamethasone may then be given, (though its use in PROM is not advised), and surveillance for signs of chorioamnionitis may begin. The patient is seen twice daily for abdominal examination. The white blood count is measured at least daily, and maternal vital signs and fetal heart rate are determined every 4 hours. Once signs of chorioamnionitis occur or labor begins (perhaps again) more than 48 hours after admission, then delivery is allowed. If the presentation is vertex, then vaginal delivery is allowed in the absence of fetal distress. Under any other circumstances, abdominal delivery is accomplished. If PROM occurs outside a hospital equipped with a regional intensive care nursery, and if maternal transport can be safely performed, then the mother is transported to a regional center. No digital cervical examination is to be performed until delivery is inevitable.(ABSTRACT TRUNCATED AT 250 WORDS)

Intrauterine growth retardation risk detection for fetuses of unknown gestational age

A method of plotting growth rate of the biparietal diameter against the concurrent size of the biparietal diameter was used to assess risk of intrauterine growth retardation. The technique does not require knowledge of gestational age of the fetus. Therefore, it is uniquely useful for patients with unknown or uncertain menstrual dates who present relatively late in pregnancy when a reliable estimate of gestational age cannot be sonographically obtained. One hundred twenty-one patients were studied. Ninety-seven percent of the fetuses who demonstrated a normal rate of growth were either appropriate or large for gestational age by weight. Thirty-five percent of the fetuses who had a subnormal rate of growth of the biparietal diameter were intrauterine growth retarded by weight. The data presented support the use of this technique for assessing the risk for intrauterine growth retardation, when an accurate estimate of gestational age cannot be made.

Routine ultrasound before termination of pregnancy

SummaryRoutine ultrasound scans were performed on 244 patients requesting termination of pregnancy. They were of value in the accurate estimation of gestational age and in the detection of early pregnancy complications. The clinical management of 24 patients was altered by the scan findings, which were thought to have contributed significantly to the management of a further 12.It is concluded that ultrasound can be of value to any patient requesting abortion and especially when there is uncertainty as to the maturity of the pregnancy or when an intra-uterine contraceptive device may be present.

Calcification of fetal teeth as an index of fetal maturation

Abdominal x-rays (by the technique of Bishop2) were taken of 70 gravid women, and fetal age was assessed by the degree of calcification of the fetal teeth. In 7 cases, the teeth could be visualized, and an accurate estimate of gestational age was made from the radiograph. However, it appears at present that visualization of the fetal teeth can be achieved only when the fetal head is not in the maternal pelvis.

Assessment of fetal size and growth rate by ultrasonic echoscopy.

Ultrasonic measurements of the size of the fetal head and trunk permit a fairly accurate estimate of gestational age in the middle trimester of pregnancy. Serial ultrasonic measurement of fetal size records fetal growth rate, which is of help in the management of gravidas with a history of previous intrauterine death, suspected placental insufficiency and, perhaps, diabetes mellitus. Small-for-dates or dysmature babies have been shown to acquire their low birth weight by one of two methods: either they grow at an evenly slow rate throughout pregnancy, or they grow normally to a point in the third trimester, after which growth stops altogether or proceeds at a much slower rate than normal.