Although renal colic is the most common cause of nonobstetric pain among hospitalized pregnant women, the diagnosis of urolithiasis remains a challenge. Many symptoms and signs may be masked by the pregnant uterus. As the pregnancy progresses, the sensation and location of the pain changes.
Approximately 25% of patients eventually diagnosed with unobstructed ureteral stones were initially misdiagnosed as appendicitis, perticulitis or placentation. In addition to the majority of patients showed low back pain, mostly with gross hematuria or microscopic hematuria, sometimes accompanied by urinary tract infection. Hematuria occurs occasionally in normal pregnancy, but painless hematuria is rare in patients with stones.
For patients with ureteral calculi during pregnancy, it is particularly important to take urine for urine culture tests because it is not uncommon for pyuria in pregnant women and to reduce the sensitivity of urine culture tests. The diagnosis of urinary calculi should be considered if pregnant women have persistent urinary tract infection or decomposed urea microbial infection. Other symptoms that may prompt urolithiasis include irritating micturition symptoms, chills, nausea and vomiting. However, other acute abdomen may also cause similar symptoms, urologists should pay close attention to the patient when examining.
The primary problem in pregnancy with urolithiasis is the effect of radiation on the fetus. The main effects of radiation on the fetus are malformation, carcinogenesis and mutagenesis. These risks of radiological examinations are related to the time of pregnancy under radiography and the amount of X-ray exposure received. The first trimester of pregnancy is organ formation and rapid cell differentiation, and embryos are extremely sensitive to radiation. Although the sensitivity of the fetus to teratogenic effects is significantly reduced during the second and third trimester of pregnancy, exposure to X-rays increases the risk of developing a malignant tumor at birth.
Although ultrasound can provide a complete picture of the kidneys, the ureter and its contents can not be completely visualized. Moreover, hydronephrosis during pregnancy is easily confused with hydronephrosis caused by stone obstruction. Restrictive intravenous pyelography may be performed, including a fluoroscopy and an abdominal plain film 30 minutes after injection of the developer. The exposure of each abdominal plain film to the fetus is 0.1rad or 0.2rad, far below the threshold of 1.2rad, which is higher than the threshold risk. In the three months before organ pregnancy and fetal risk, X-ray irradiation is especially avoided.
However, ultrasound diagnosis of urinary tract stones in pregnancy has some defects, such as the sensitivity is not high, the accuracy rate of stone diagnosis is between 34%~86% and specificity. It can not identify lithiasis and physiological hydronephrosis. It has low diagnostic accuracy for pelvic ureteral calculi. Transvaginal ultrasound can improve the diagnostic accuracy of pelvic ureter stones, the technology easier to get in the clinic to promote the use of its shortcomings can not be the upper ureteral calculi to make the appropriate examination diagnosis.