ACOG updates its recommendations for estimating gestational age and due date: May Accurate gestational dating of pregnancy is very important for optimal . ACOG issues guidelines for obstetrics analgesia an. ObGFirst FREE TRIAL | Guideline Notifications | Daily Research Summaries . ACOG AIUM Practice Bulletin Ultrasound in Pregnancy. Delivery management of a pregnancy in a woman with a prior cesarean delivery also can be complicated by suboptimal pregnancy dating. In suitable.
This document reflects emerging clinical and scientific advances as of the date issued and is subject to change. The information should not be construed as dictating an exclusive course of treatment or procedure to be followed.
Accurate dating of pregnancy is important to improve outcomes and is a research and public health imperative.
As soon as data from the last menstrual period, the first accurate ultrasound examination, or both are obtained, the gestational age and the estimated due date EDD should be determined, discussed with the patient, and documented clearly in the medical record. Subsequent changes to the EDD should be reserved for rare circumstances, discussed with the patient, and documented clearly in the medical record.
When determined from the methods outlined in this document for estimating the due date, gestational age at delivery represents the best obstetric estimate for the purpose of clinical care and should be recorded on the birth certificate. For the purposes of research and surveillance, the best obstetric estimate, rather than estimates based on the last menstrual period alone, should be used as the measure for gestational age.
Recommendations The American College of Obstetricians and Gynecologists, the American Institute of Ultrasound in Medicine, and the Society for Maternal—Fetal Medicine make the following recommendations regarding the method for estimating gestational age and due date: For instance, the EDD for a pregnancy that resulted from in vitro fertilization should be assigned using the age of the embryo and the date of transfer.
As soon as data from the last menstrual period LMPthe first accurate ultrasound examination, or both are obtained, the gestational age and the EDD should be determined, discussed with the patient, and documented clearly in the medical record. For the purposes of research and surveillance, the best obstetric estimate, rather than estimates based on the LMP alone, should be used as the measure for gestational age. Introduction An accurately assigned EDD early in prenatal care is among the most important results of evaluation and history taking.
This information is vital for timing of appropriate obstetric care; scheduling and interpretation of certain antepartum tests; determining the appropriateness of fetal growth; and designing interventions to prevent preterm births, postterm births, and related morbidities.
ACOG Reinvents the Pregnancy Wheel - ACOG
Appropriately performed obstetric ultrasonography has been shown to accurately determine fetal gestational age 1. A consistent and exacting approach to accurate dating is also a research and public health imperative because of the influence of dating on investigational protocols and vital statistics. This Committee Opinion outlines a standardized approach to estimate gestational age and the anticipated due date. However, there is great usefulness in having a single, uniform standard within and between institutions that have access to high-quality ultrasonography as most, if not all, U.
Accordingly, in creating recommendations and the associated summary table, single-point cutoffs were chosen based on expert review. Because this practice assumes a regular menstrual cycle of 28 days, with ovulation occurring on the 14th day after the beginning of the menstrual cycle, this practice does not account for inaccurate recall of the LMP, irregularities in cycle length, or variability in the timing of ovulation.
It has been reported that approximately one half of women accurately recall their LMP 2—4. Accurate determination of gestational age can positively affect pregnancy outcomes.
For instance, one study found a reduction in the need for postterm inductions in a group of women randomized to receive routine first-trimester ultrasonography compared with women who received only second-trimester ultrasonography 5. A Cochrane review concluded that ultrasonography can reduce the need for postterm induction and lead to earlier detection of multiple gestations 6. Because decisions to change the EDD significantly affect pregnancy management, their implications should be discussed with patients and recorded in the medical record.
Late-term delivery is indicated at 41 weeks of gestation when gestational age is uncertain, using the best clinical estimate of gestational age. Initiation of antepartum fetal surveillance at 39—40 weeks of gestation may be considered for suboptimally dated pregnancies. During the antenatal care of a woman with a suboptimally dated pregnancy, it is reasonable to consider an interval ultrasonographic assessment of fetal weight and gestational age 3—4 weeks after the initial ultrasonographic study.
Recommendations The American College of Obstetricians and Gynecologists the College makes the following recommendations and conclusions: The timing of indicated delivery in a woman with a suboptimally dated pregnancy should be based on the best clinical estimate of gestational age.
Although this follow-up examination is intended to support the working gestational age, interval fetal growth assessment potentially may detect cases of fetal growth restriction. Given concern that a full-term or late-term suboptimally dated pregnancy could actually be weeks further along than it is believed to be, initiation of antepartum fetal surveillance at 39—40 weeks of gestation may be considered.How accurate is a due date that is determined by ultrasound?
Introduction Contemporary efforts to curb elective deliveries before 39 weeks of gestation are intended to reduce risks of neonatal respiratory and nonrespiratory morbidities that are more frequently associated with early-term birth 1—3. Implicit in strategies to reduce nonmedically indicated early deliveries is a best clinical estimate of gestational age 45.
Defining a Suboptimally Dated Pregnancy The American College of Obstetricians and Gynecologists considers first-trimester ultrasonography to be the most accurate method to establish or confirm gestational age 6. In the second and third trimesters, ultrasonographic biometric dating has a range of inaccuracy that increases with advancing gestational age. A recommended week cutoff for the determination of a suboptimally dated pregnancy replaces an established historic threshold at 20 weeks of gestation.
This proposed cutoff also is consistent with the recent College recommendation that the optimal time for a single ultrasonographic examination during pregnancy is at 18—22 weeks of gestation because ultrasonography performed during this time allows for fetal anatomical assessment and accurate estimation of gestational age 7.
- ACOG Releases Guidelines on Management of Post-term Pregnancy
Deliveries in Women With Suboptimally Dated Pregnancies Consistent with the practice for accurately dated pregnancies, the timing of indicated delivery in a woman with a suboptimally dated pregnancy should be based on the best clinical estimate of gestational age.
However, there is no role for elective delivery in a woman with a suboptimally dated pregnancy. Without a risk for the woman or the fetus that is considered sufficient to warrant delivery, elective delivery could introduce unnecessary risk of neonatal morbidity if the pregnancy proves to be earlier in gestation than originally estimated. Indicated preterm deliveries in women with suboptimally dated pregnancies should be based on the best clinical estimate of gestational age.
Although guidelines for indicated late-preterm and early-term deliveries depend on accurate determination of gestational age, women with suboptimally dated pregnancies should be managed according to these same guidelines because of the lack of a superior alternative 89.
There does appear to be a slight advantage to labor induction using cervical-ripening agents.
What is the role of prostaglandin preparations in managing a post-term pregnancy? Prostaglandin is a valuable tool for improving cervical ripeness and inducing labor; however, no standardized dose or dosing interval has been established.
Lower doses of prostaglandins are preferred, because higher doses have been associated with an increased risk of uterine tachysystole and hyperstimulation leading to nonreassuring fetal testing results. When prostaglandin is used, routine fetal heart monitoring should be performed because of the risk of uterine hyperstimulation.
Management of Suboptimally Dated Pregnancies - ACOG
Is there a role for vaginal birth after cesarean delivery in the management of post-term pregnancy? Because of limited evidence on the safety or efficacy of vaginal birth after cesarean delivery after 42 weeks of gestation, the authors make no recommendation for its use as an alternative to elective repeat cesarean deliveries for some women. Summary of Recommendations The following recommendations are based on good and consistent scientific evidence Level A: Women with post-term gestations who have unfavorable cervices can either undergo labor induction or be managed expectantly.
Prostaglandin can be used in post-term pregnancies to promote cervical ripening and induce labor. Delivery should be effected if there is evidence of fetal compromise or oligohydramnios.
Women's Health Care Physicians
The following recommendations are based primarily on consensus and expert opinion Level C: Despite a lack of evidence that monitoring improves perinatal outcome, it is reasonable to initiate antenatal surveillance of post-term pregnancies between 41 weeks days; EDD plus seven days and 42 weeks days; EDD plus 14 days of gestation because of evidence that perinatal morbidity and mortality increase as gestational age advances.
Many practitioners use twice-weekly testing with some evaluation of amniotic fluid volume beginning at 41 weeks of gestation. A nonstress test and amniotic fluid volume assessment a modified BPP should be adequate.
Many authorities recommend prompt delivery in a post-term patient with a favorable cervix and no other complications. Read the full article. Get immediate access, anytime, anywhere.