A 28-year-old primigravid woman presents to the clinic at 8 weeks of gestation for her initial prenatal visit. She has no significant past medical history and takes only a daily prenatal vitamin. Her vital signs are within normal limits. Laboratory evaluation reveals a blood type of A, Rh-negative, with a negative antibody screen. The patient intends to pursue all standard recommended prenatal care. Arrange the following routine prenatal screening and prophylactic interventions in the correct chronological sequence in which they should be offered or administered during her uncomplicated pregnancy.
- 1First-trimester combined screening for aneuploidy
- 2Fetal anatomic survey via ultrasound
- 350-g 1-hour oral glucose challenge test
- 4Prophylactic administration of anti-D immune globulin
- 5Rectovaginal culture for Group B Streptococcus
Answer
The correct chronological sequence is: First-trimester combined screening (11-14 weeks), followed by the fetal anatomic survey (18-22 weeks), then the 50-g oral glucose challenge test (24-28 weeks), followed by prophylactic anti-D immune globulin administration (28 weeks), and finally the Group B Streptococcus culture (36-38 weeks).
Routine prenatal care follows a strict chronological timeline. Aneuploidy screening is typically initiated first (11-14 weeks), followed by a comprehensive anatomic evaluation via ultrasound (18-22 weeks). In the late second to early third trimester, patients are screened for gestational diabetes (24-28 weeks) and, if Rh-negative, receive prophylactic anti-D immune globulin at 28 weeks. Finally, a rectovaginal swab for Group B Streptococcus is collected near term (36-38 weeks).
Step-by-Step Solution
Key Concept
Routine prenatal screening and prophylaxis timeline