The nurse is interviewing a client who is pregnant in her first trimester, and the client inquires about their gestational age. The nurse understands which assessment will provide the most accurate gestational age?
The nurse is interviewing a client who is pregnant in her first trimester, and the client inquires about their gestational age. The nurse understands which assessment will provide the most accurate gestational age?
A. Nägele’s rule
[41%]
B. Ultrasonography
[47%]
C. Fundal height
[9%]
D. Human chorionic gonadotropin (HCG) levels
[3%]
Statistics
Subject/Lesson
Subject
Maternal & Newborn Health
Lesson
Antepartum
Client Need
Test Plan
Health Promotion and Maintenance
Related Topic
Ante/Intra/Postpartum and Newborn Care
Item Type
Item Type
Analysis
Explanation
Choice B is correct. Early ultrasound examination, typically performed between weeks 6 and 9 of pregnancy, is one of the most accurate methods for determining gestational age during the first trimester. The ultrasound can measure the length of the fetus (crown-rump length) and provide a highly accurate estimate of gestational age. This method is particularly reliable during the first trimester when fetal development is relatively consistent among pregnancies.
Choice A is incorrect. Nägele's rule is not the most accurate way to determine a prenatal client's due date. Especially if the menstrual cycle is irregular. Nägele's rule involves subtracting 3 months from the date the LNMP began, adding 7 days, and then correcting the year, if appropriate.
Choice C is incorrect. Fundal height is an inexpensive and noninvasive method of evaluating fetal growth and confirming gestational age. It is measured from the top of the symphysis pubis, over the abdominal curve, to the top of the fundus.
Fundal height measurements can be influenced by factors such as maternal body habitus, fetal position, and amniotic fluid volume, leading to variability and reduced accuracy compared to ultrasonography.
Choice D is incorrect. Human chorionic gonadotropin (hCG) is produced by the trophoblastic cells surrounding the developing embryo. The primary function of hCG in early pregnancy is to prevent deterioration of the corpus luteum so it can continue producing estrogen and progesterone until the placenta is sufficiently developed. The presence of this hormone produces a positive pregnancy test result but does not assist in the determination of EDD.
Related Videos
2 Key Topics
1st Trimester
28.1 Pregnancy Basics & Early Assessment
Additional Info
✓ Obstetric ultrasound is a procedure in which high-frequency sound waves obtain real-time images of maternal structures, placenta, amniotic fluid, and fetus
✓ Obstetric ultrasound can be done transabdominally or transvaginally
✓ The maternal bladder may need to be full when either approach is used in the first trimester to allow for better visualization
✓ In the transabdominal approach, a water-soluble transmission gel or lotion is applied to the maternal abdomen as a lubricant to increase the transmission of sound waves
