A nurse is teaching a newly licensed nurse about the uses of ultrasonography in the first trimester of pregnancy. Which of the following statements by the newly licensed nurse indicates an understanding of the teaching?

The correct answer is c. Ampicillin.

Rationale:

• Group B Streptococcus (GBS) B-hemolyticis a bacterium that can colonize the vagina and rectum of pregnant women.While usually harmless to the mother,it can be passed to the newborn during birth and cause serious infections,including pneumonia,meningitis,and sepsis.
• Ampicillinis thefirst-line antibioticrecommended by the Centers for Disease Control and Prevention (CDC) for theprevention of GBS disease in newborns.It belongs to thepenicillin classof antibiotics,which are highly effective against GBS and generally well-tolerated by pregnant women and newborns.
• Doxycyclineis not recommended for GBS prophylaxis due to its poor penetration into amniotic fluid and potential for causing tooth discoloration and bone development problems in newborns.
• Cefotetanis an alternative option for women with penicillin allergy,but ampicillin is still preferred due to its lower cost and broader spectrum of activity against GBS strains.
• Fluconazoleis an antifungal medication and has no activity against GBS bacteria.

Detailed Rationale for Each Choice:

a. Doxycycline:

• Rationale against:
  • Poor penetration into amniotic fluid:Doxycycline does not effectively reach the amniotic sac,where the baby is surrounded,and therefore may not adequately protect the newborn from GBS infection.
  • Adverse effects in newborns:Doxycycline can cause tooth discoloration and bone development problems in infants exposed in utero.

b. Cefotetan:

• Rationale for:
  • Alternative for penicillin allergy:Cefotetan is a cephalosporin antibiotic effective against GBS and can be used in women with penicillin allergy.
• Rationale against:
  • Second-line option:Ampicillin is the preferred choice due to its lower cost and broader spectrum of activity against GBS strains.

c. Ampicillin:

• Rationale for:
  • First-line antibiotic:Ampicillin is the CDC-recommended first-line antibiotic for GBS prophylaxis due to its:
    • High effectiveness against GBS:Ampicillin has a broad spectrum of activity against GBS strains.
    • Good safety profile:Ampicillin is generally well-tolerated by pregnant women and newborns.
    • Cost-effectiveness:Ampicillin is a relatively inexpensive antibiotic compared to other options.

d. Fluconazole:

• Rationale against:
  • Antifungal medication:Fluconazole is an antifungal medication and has no activity against GBS,which is a bacterium.

The correct answer is choice **b. Hearing loss**.

Choice A rationale:

Cataracts are not a common finding in newborns with congenital CMV infection. Cataracts are more commonly associated with other congenital infections like rubella, toxoplasmosis, and herpes simplex virus (HSV).

Choice B rationale:

Hearing loss is one of the most common manifestations of congenital CMV infection. Up to 40-58% of infants with symptomatic congenital CMV infection develop sensorineural hearing loss, which can be unilateral or bilateral, and progressive over time.

Choice C rationale:

Macrosomia, or large birth size, is not a typical finding in congenital CMV infection. In fact, infants with symptomatic congenital CMV infection are more likely to be small for gestational age or have intrauterine growth restriction.

Choice D rationale:

Urinary tract infection (UTI) is not a common presentation of congenital CMV infection. CMV can cause inclusion bodies in the urine, but overt UTI is not a typical finding. More common manifestations include petechiae, hepatosplenomegaly, jaundice, and central nervous system involvement.