The purpose of this research study is to compare the amount of protein excreted by the kidneys in a 24-hour period between patients who have a kidney infection and those who do not have a kidney infection.

Preeclampsia is a pregnancy-unique disorder that is cured only with delivery of the baby, even if the pregnancy is premature. Defined by both blood pressure and proteinuria criteria, diagnosis is often obscured by renal processes like systemic lupus erythematosus or nephrotic syndrome that increase urinary protein spillage. Proteinuria is defined as a total protein urinary excretion exceeding 300 mg in a 24-hour urine collection in pregnancy. This is suggested to be double the protein excretion in the non-pregnancy population at 150 mg/day. A mean 24-hour urine protein excretion of 204.3 mg (± 92.5) was found in the non-hypertensive pregnant population.

Physiological changes in pregnancy predispose patients to urinary tract infections; ureteral compression by the gravid uterus, progesterone-mediated slowing of ureteral peristalsis and decreased bladder tone, and mechanical compression of the bladder contribute to impaired clearance of bacteria from the urinary tract. Indeed, acute cystitis complicates 2-4% of all pregnancies. While it has been said that urinary tract infections increase proteinuria, it is unknown how much protein spillage should be expected in the general or the pregnant populations. Hence a patient with pyelonephritis may obscure the diagnosis of preeclampsia if she spills urinary protein from her infection.

The purpose of this study is to compare the mean of 24-hour urine protein in pregnant patients with and without acute pyelonephritis.

The importance of this study will be to determine if urine protein excretion is in fact increased in the setting of pyelonephritis. This will allow for reliable evaluation of urine protein during the work up for preeclampsia in those women also found having a kidney infection.

Inclusion Criteria:

• Women ≥ 18 years old admitted at Miller Children and Women's Hospital Long Beach Memorial Medical Center
• Gestational age between 20 weeks and 0 days to 41 weeks and 0 days
• Singleton pregnancy
• Pyelonephritis group:

meeting 2 out of 3 criteria:

1. Fever > 100.4
2. Costovertebral angle tenderness
3. Positive urine culture - without pyelonephritis group: without acute cystitis and pyelonephritis

Positive culture defined as: quantitative count of ≥ 100,000 CFU/mL or single catheterized urine specimen with quantitative count of 100 CFU/mL.

Exclusion Criteria:

• Chronic hypertension
• Pre-gestational diabetes
• Autoimmune disorders
• Preexisting renal disease
• Multiple gestation
• Vaginal bleeding
• Preeclampsia
• Hospital admission > 3 days

All patients admitted to inpatient management of acute pyelonephritis meeting the inclusion and exclusion criteria will be enrolled in the study. A 24 hour urine collection with be performed for evaluation of protein.