A nurse is teaching a pregnant client about nausea. Which intervention is best?

Ectopic pregnancy occurs when a fertilized ovum implants outside the endometrial cavity, most commonly in the fallopian tube. It presents a high risk for tubal rupture and intra-abdominal hemorrhage. Diagnosis relies on combining quantitative beta-hCG levels with transvaginal ultrasonography findings.

A. Fetal heart beat in uterus: Visualization of an intrauterine pregnancy virtually excludes the possibility of a concurrent ectopic gestation, except in rare heterotopic pregnancies. This finding confirms a normally implanted fetus. It does not provide evidence for an extrauterine implantation site.

B. Elevated BP: Hypertension is not a diagnostic feature of early ectopic pregnancy and is more commonly associated with preeclampsia or chronic vascular disease. While a ruptured ectopic can cause hypotension due to shock, high blood pressure is irrelevant to confirming the location of the pregnancy.

C. Fetal heartbeat outside the uterus: Definitive confirmation is achieved when an extrauterine embryo with detectable cardiac activity is visualized via ultrasound. This finding provides absolute evidence that the pregnancy is located in an abnormal site. It is the most conclusive diagnostic indicator available.

D. Normal hCG: In an ectopic pregnancy, hCG levels often rise more slowly than expected or remain abnormally low for the gestational age. A "normal" or rapidly doubling hCG level is more characteristic of a healthy intrauterine pregnancy. This finding would decrease suspicion of an ectopic.

Naegele’s rule estimates the expected date of delivery by calculating 280 days from the onset of the last menstrual period. This assumes a standard 28-day cycle with ovulation occurring on day 14. Standard human gestation is approximately 40 gestational weeks duration.

A. LMP + 1 year: Adding a full calendar year to the last menstrual period results in an inaccurate delivery date that exceeds the standard 40-week human gestation. This calculation fails to account for the necessary 3-month subtraction required by established obstetric formulas. It ignores biological developmental timelines.

B. Add 3 months: Adding three months to the last menstrual period would suggest a pregnancy duration of only 12 to 15 weeks. This significantly underestimates the physiological time required for full fetal maturation and organogenesis. Standard gestation requires approximately nine calendar months.

C. LMP-3 months + 7 days: This formula, known as Naegele's rule, accurately adjusts the calendar year to reflect a 280-day cycle. Subtracting 3 months and adding 7 days to the first day of the last menses provides the most reliable clinical estimate. It is the gold standard for dating.

D. Add 7 days only: Adding 7 days without adjusting the month or year would result in a date nearly one year after the onset of menses. This does not align with the biological reality of human pregnancy duration. Proper dating requires both day and month adjustments.