B: PRENATAL VISITS AND NAEGELE’S RULE
Prenatal visits are required:
• Monthly until week 28
• Biweekly from week 28 till week 36
• Weekly from week 36 till week 42 or until delivery
• Labor is usually induced at week 42 or a C-section is scheduled.
During the first prenatal visit, Naegele’s
rule is used to calculate the estimated due
date (EDD), also known as the estimated
date of confinement (EDC).
The EDD is calculated by adding and subtracting the following to the first day of the
last menstrual period (LMP):
-Add 1 year and 7 days to the first day of
the LMP.
-Subtract 3 months.
-For example, if the last menstrual period
was from December 6–11, 2015, adding 1
year, 7 days to Dec. 6 will give December
13, 2016, and subtracting 3 months will
give an EDD of September 13, 2016.
- An easier way of calculating this is by
simply adding 9 months and 7 days to the
first day of LMP, which gives the same
September 13, 2016 date.
The following physical assessments, tests, or analysis should be performed during the prenatal visits:
- Measuring weight gain during pregnancy.
Recommended weight gain in pregnancy
is 25–33 pounds, or 29 ± 4 pounds. The
weight gain is distributed as follows:
• First trimester: 1 pound every month, total 3
pounds.
• Second and third trimester: 1 pound every
week, total 30 pounds. Weight gain for a 42
weeks pregnancy should be 33 pounds.
• Weight gain = Number of weeks – 9.
Pregnancy week: 12 15 18 21 30 40 42
Weight in pounds: 3 6 9 12 21 31 33
-The fetal heart rate is also measured during
the prenatal visits and can only be auscultated after 10 weeks of pregnancy.
-Another measurement obtained during
the prenatal visit is the fundal height that
is only palpable after week 12 when the
weight gain is at least 3 pounds.
-A detailed urinalysis for presence of
proteins and glucose is also performed in
addition to any signs of complications or
troubles the pregnancy may be causing.
EXAM TIPS
Know how to calculate the EDD using Naegele’s rule.
Know the expected weight gain during pregnancy, and this can be gotten from the formula weight gain = Number of weeks-9. And note there is a ±4 pounds threshold.
For example, the nurse in a prenatal client is assessing a client who is 28 weeks pregnant with a weight gain of 24 pounds. Which of the following conclusion by the nurse is correct?
A. The client is gaining weight properly, so there is no risk to the fetus.
B. The client is gaining more weight than normal.
C. The client is underweight for her gestational
age.
D. The client is an increased risk of having a
small-for-gestational-age baby.
The right answer is B which is the client is overweight because the normal weight for a 28 weeks gestation should be 19±4.
Excessive weight gain during pregnancy causes increased risk of complications and also increases the metabolic demands of the heart during pregnancy.
Know the schedule of prenatal visits during pregnancy
