**2.1.5.1 Hemolytic uremic syndrome(HUS)/Idiopathic post partum failure**

It occurs in primipara and is characterized by renal failure, anemia and hypertension. The risk for P-aHUS is highest during a second pregnancy. Onset is within hours to days post partum. Symptoms can begin before delivery, but the onset in most cases is delayed for 48 hours or more after delivery (mean four weeks). HUS may follow a normal pregnancy or be preceded by findings indistinguishable from preeclampsia. HUS with severe renal failure more frequently presents in the postpartum period. Presenting symptoms are often nonspecific , although majority (60%) present with bleeding. Hypertension is seen in 75% of cases. Hemolysis and anemia may be absent at presentation in 50% of cases. DIC is rare.

**Labs** - Obligate findings include hemolytic anemia (hematocrit < 30% with schistocytes on peripheral smear) and thrombocytopenia under 100,000/μ L (50% of patients will have counts < 20,000/μ L). LDHis usually >600 U/liter. Hemolytic anemia is coomb's negative. There may be hypocomplementemia, deficiency in prostaglandins or antithrombin levels. HUS is a clinical diagnosis. Tissue biopsy is not required. In problematic cases when renal biopsy is done it shows mesangiolysis and glomerular simplification.

**Outcomes**- The outcomes are poor. 80-90% survive acute episode. There is a high maternal mortality of 18-44% and fetal loss is seen in 80%. 62% reached ESRD by 1 month. Outcomes do not differ between patients with pregnancy-related and non-pregnancy–related aHUS. Pregnancies in female patients with complement abnormalities are complicated by fetal loss and preeclampsia in 4.8% and 7.7%,respectively. (Fadi Fakhouri,2010) Almost half have residual neurologic or chronic renal failure. Recurrences occur in 50%. Long-term sequelae, such as hypertension and chronic renal failure, are observed in 44% of patients with HUS. The perinatal mortality rate is as high as 30%.

**Treatment** includes Plasmapheresis. Plasma infusion alone is less effective. Steroids, antiplatelet therapy, Immunoabsorption, splenectomy, IV gamma globulin therapy have been used in different studies. Renal failure is managed by hemodialysis. Antihypertensives are used for control of blood pressure. Platelet transfusions should be avoided. Heparin and fibrinolytic agents and anti thrombin III concentrates may be used. Dilatation and curettage should be considered when the disease occurs very close to delivery.

#### **2.1.5.2 Thrombotic thrombocytopenic purpura**

TTP is characterized by the pentad of microangiopathic hemolytic anemia, thrombocytopenia, renal insufficiency, fever, and neurologic abnormalities. TTP usually occurs antepartum , about 12 % in the first trimester, 56 % in the second trimester, and 33 % in the third trimester/postpartum(Egerman RS, 1996), There may be mild renal failure and severe neurological involvement (headache, altered consciousness, seizures, hemiparesis), and fever. Severe thrombocytopenia and hemolytic anemia may be seen. Examination

Acute Kidney Injury in Pregnancy 165

Significant blood loss due to antepartum or postpartum hemorrhage may cause ischemic

Antepartum hemorrhage may be due to placenta praevia or concealed hemorrhage due to abruptio placentae which is usually associated with PIH. Treatment consists of intravascular volume repletion and blood transfusions. If the acute renal failure is due to pre renal intravascular volume depletion and is corrected rapidly the patient may recover without dialysis. However if the insult is prolonged it may lead to acute tubular necrosis for which

It is an important cause of AKI. According to World Health Organization puerperal sepsis is defined as infection of the genital tract occurring at any time between the rupture of membranes or labor and the 42 day post partum in which 2 or more of the following are present: pelvic pains, fever oral temperature 38,5°C or higher on any occasion, abnormal vaginal discharge (example presence of pus), abnormal smell or foul odour of discharge, delayed uterine involution. The causative organisms are gram positive streptococcus pyogenes, staphylococcus aureus, coliforms,Chlamydia and Clostridium tetani. (Momoh ,2010)Causes are prolonged rupture of membranes, obstructed labour, frequent vaginal examinations, anemia, caesarean section etc. .The source of infection may be from the retained products of conception where there may be a history of foul smelling lochia and the retained products can be demonstrated on imaging. High vaginal swab culture may help to identify the causative organism. Other sources may be urinary tract infection or mastitis. Hence a detailed physical examination including the breast examination should be undertaken. Treatment consists of appropriate antibiotics according to the culture sensitivity reports. Surgery to remove the retained products or abscess drainage even hysterectomy in

Another important cause of renal failure in pregnancy is UTI. UTIs are the most common renal disease occurring during pregnancy and range from asymptomatic bacteriuria to pyelonephritis. UTIs have been associated with SGA babies, premature labor, IUD, anemia and hypertension in mother. In some cases upper UTI may be associated with renal failure. Pregnant females are at risk for development of UTIs (2-10%), because of anatomic and

Bacteriuria occurs in 2 to 7 % of pregnancies, particularly in multiparous women, a similar prevalence as seen in nonpregnant women. A clean-voided specimen containing more than 1 lakh organisms per milliliter suggests infection. Bacteriuria often develops in the first month of pregnancy and is frequently associated with a reduction in concentrating ability. 30% of patients develop pyelonephritis if asymptomatic bacteriuria is left untreated. Universal screening is therefore recommended in all pregnant females. Screening for asymptomatic bacteriuria should be performed at 12 to 16 weeks gestation (or the first prenatal visit, if that occurs later). Rescreening is generally not performed in low risk women, but can be considered in women at high risk for infection (eg, presence of urinary tract anomalies, hemoglobin S, or preterm labor). Dipstick has a sensitivity of <50% and

physiologic changes that occur in normal pregnancy.UTI may be classified as:

**2.1.6 Antepartum and post partum hemorrhage** 

injury and lead to obstetric acute renal failure.

dialysis is needed.

**2.1.7 Puerperal sepsis** 

extreme cases may be needed.

**2.1.8 Urinary Tract Infections (UTI)** 

**2.1.8.1 Asymptomatic bacteriuria** 

shows petechiae, ecchymoses, and nose and gum bleeding . Rarely hematuria, gastrointestinal bleeding and intracranial bleeding may occur. Bleeding associated with surgery is uncommon unless the platelet counts are lower than 50,000/μ L. Clinically significant spontaneous bleeding is rare unless counts fall below 10,000/μ L.
