Review Question - QID 108648

This patient is postpartum day 3 with new fever, uterine tenderness, and foul smelling purulent lochia, consistent with a diagnosis of postpartum endometritis. There are many risk factors for this condition, but the most significant is delivery by C-section.

Postpartum endometritis is a leading cause of maternal morbidity and mortality and typically presents several days after delivery with fever, tachycardia, uterine tenderness, purulent discharge, and constitutional symptoms (malaise, anorexia, headache, chills). Major risk factors include C-section (especially after onset of labor), prolonged labor and/or prolonged rupture of membranes, HIV, group B streptococcus colonization, and maternal diabetes. This patient has many of these risk factors. However, C-section is still by far the most important, as the rate of endometritis following a C-section after onset of labor, even with antibiotic prophylaxis, is four times higher than with vaginal delivery. Diagnosis is primarily clinical but can be supported by a complete blood count with a significant left shift and elevated lactic acid. The white blood count is often already elevated as a byproduct of delivery and therefore does not always provide additional information. There are no specific sonographic findings for postpartum endometritis. The most common pathogens include streptococcus and staphylococcus, anaerobes, and gram-negative bacteria. Empiric treatment is generally clindamycin and gentamicin together.

Incorrect Answers:
Answer 1: HIV positive status is a risk factor for postpartum endometritis, and the pathogens involved can include less common organisms such as herpes simplex virus and cytomegalovirus. Although this patient attempted a vaginal delivery (her viral load was less then the cutoff of 1000 copies/mL, above which vaginal delivery is contraindicated), she ultimately required C-section after a prolonged labor, which is what likely put her at greatest risk for endometritis. If she receives empiric antibiotics and does not improve, it is reasonable to try antivirals such as acyclovir instead.

Answer 2: Prolonged rupture of membranes is defined as 18-24 hours passing between rupture and delivery. This patient technically did not meet this criteria, though it could have put her at risk for both endometritis and chorioamnionitis if she had. These two conditions are often associated, but chorioamnionitis is an infection of the intra-amniotic space rather than the uterus itself and requires maternal fever with one of the following: fetal tachycardia, maternal tachycardia, maternal leukocytosis, fundal tenderness, and foul smelling amniotic fluid. Treatment is ampicillin and gentamicin.

Answer 4: Herpes simplex virus in a woman can cause neonatal herpes encephalitis or other manifestations (ocular, hepatic, or skin lesions) in her child by vertical transmission. This is most common if there are active herpetic lesions in the genital area at the time of delivery, in which case C-section would be required. This woman has a history of herpes transmission to her previous child and may be at risk for doing so again, but this is not as significant a risk factor for endometritis as C-section is.

Answer 5: Maternal diabetes also increases the risk of postpartum endometritis, though the exact cause is not established. However, this is not as significant a risk as C-section, and this patient’s diabetes was well controlled during her pregnancy. Maternal type I diabetes is a major risk factor for congenital anomalies such as caudal regression syndrome, preterm delivery, and infant hypoglycemia and low birth weight. Aggressive glycemic control is therefore very important.

Bullet Summary:
Postpartum endometritis presents fever, uterine tenderness, and foul smelling lochia. C-section is the most important risk factor, and treatment includes clindamycin and gentamicin.