Problems with the kidneys and ureters—tubes that lead from the kidneys to the bladder—can sometimes lead to hydronephrosis. Hydronephrosis is a blockage in the kidney that causes the flow of urine to the bladder to be obstructed. Hydronephrosis can cause eventually cause kidney atrophy. Pregnant women have a higher chance of this difficulty as their uterus enlarges. Treatments do exist for hydronephrosis in pregnancy; however, most cases are mild and go away after birth.
When ureters cannot transport urine to the bladder from the kidneys because of an obstruction, the kidneys can enlarge and fill with urine. According to Merck, urine flows out of the kidneys at a low pressure; however, an obstruction can make it difficult for ureters to excrete urine. This blockage increases pressure on internal structures and can cause kidney damage or even loss of kidney function.
According to the European Journal of Obstetrics, Gynecology and Reproductive Biology, hydronephrosis in pregnancy typically occurs after the 20th week of pregnancy as the enlarging uterus may compress ureters. Also, Merck states that hormonal changes may aggravate the problem, as they may reduce muscular contractions that normally help push urine through the ureters.
For a blockage that occurs quickly, intense, intermittent pain between the ribs and hips can be excruciating. A blockage at both kidneys can result in not being able to pass urine. Those who develop hydronephrosis slowly may not notice symptoms at all.
According to the European Journal of Obstetrics, Gynecology and Reproductive Biology, most pregnant women complain of pain on their right side. Oftentimes women with a history of renal disease will also develop hydronephrosis.
The European Journal of Obstetrics, Gynecology and Reproductive Biology states that though mild blockages may occur in the majority of pregnancies, more problematic hydronephrosis cases can be easily detected through ultrasound technology.
Merck also says that an imaging test may be used to determine the cause of the obstruction in non-pregnant patients.
Hydronephrosis of pregnancy is cured after the baby is born. However, the renal pelvis and ureters may stay swollen after birth. Lying on the unaffected side helps to alleviate the symptoms during pregnancy. Most hydronephrosis cases occur on the right side, so lie on your left side for relief. When symptoms persist and there is fear of renal failure, an indwelling ureteral catheter may be inserted. The European Journal of Obstetrics, Gynecology and Reproductive Biology says this a relatively simple procedure carried out with local anesthesia. During this procedure, a catheter—a flexible, tube—is placed in the ureter to help excrete urine.
For more serious cases, the Digital Urology Journal suggests ureteral stenting, which is the insertion of a thin tube into the the ureter to prevent or treat a blockage of urine from the kidneys. Serious cases can also be treated with an establishment of percutaneous drainage to help with pain relief and to prevent spontaneous renal rupture. During a percutaneous drainage procedure, a thin needle is inserted into the fluid to help drain excess urine.
Induced labor and an epidural block for pain are the final steps for severe cases that can't be helped by other means.