Review Question - QID 102535

While already in her second trimester, this patient is presenting for her first perinatal visit. Hepatitis B, urinary tract infections, and blood type, among others (as described below), are conditions for which all women are screened at their first prenatal visit.

During the initial obstetric visit, all women should have a CBC, blood type, Rh antibody screen, urinalysis, syphilis RPR, rubella immune status, varicella immune status, hepatitis B surface Ag, and HIV testing. For patients under 25 years of age or with risk factors, chlamydia testing should be performed. For patients with selected risk factors, testing for the following infections and conditions may be pertinent: Neisseria gonorrhea, tuberculosis, toxoplasmosis, hepatitis C, bacterial vaginosis, trichomoniasis, herpes simplex virus, Chagas disease, sickle cell gene, thyroid dysfunction, and glucose challenge testing. An ultrasound to determine gestational age is recommended at 6-11 weeks gestation. At 15-19 weeks a triple-marker screen or quadruple screen should be performed to assess for developmental defects. Screening ultrasound for fetal and placental anatomy is performed between 18-21 weeks. Between 26-28 weeks, glucose tolerance testing and a repeat CBC should be obtained. If the patient is at risk for Rh-incompatibility, RhoGAM should also be initiated at this visit. Group B strep screening occurs at 35-37 weeks.

In a review for prenatal care, Kirkham et al. discuss important topics to be covered in the first prenatal visit. These include: air travel, breast feeding, exercise, medications safe for pregnancy, alcohol and drug use, smoking, and intercourse during pregnancy.

In an observational trial, Sevket et al. studied the utility of hemoglobin A1c (HbA1c) in the diagnosis of gestational diabetes at 24-28 weeks gestation. The authors found that a HbA1c level of greater than or equal to 5.2 had a sensitivity of 64.15% and specificity of 67.48% in diagnosing gestational diabetes when compared to the gold standard of oral glucose tolerance testing. The authors concluded that HbA1c was not a useful screening test for gestational diabetes.

Incorrect Answers:
Answer 1: Hepatitis C testing is not a part of routine prenatal care, though it is indicated for women with certain risk factors (i.e. history of IV drug use, HIV infection, incarceration).
Answer 2: HPV testing is not a specific part of prenatal care, though routine gynecologic and cervical cancer screening is still recommended.
Answer 3: CMV and HSV testing are not a part of routine prenatal care. Only at risk women should receive testing for toxoplasmosis.
Answer 4: Only women with a prior history of gestational diabetes or a first degree relative with a history of gestational diabetes should receive a glucose tolerance test before 18-21 weeks.