Lectures on urinary infections and pregnancy

2021-03-22 12:00 AM

Some authors find that about 25% of asymptomatic urinary infections lead to symptomatic urinary tract infections.


Urinary tract infections are common diseases in women, especially high frequency in cases of pregnancy. Sometimes urinary tract infections occur silently, quietly with no obvious symptoms, but most have manifestations of urinary function depending on the parts of the urinary system such as forms of cystitis, radioitis. pyelonephritis, unilateral or bilateral nephritis. Foci of infection can be detected early before pregnancy or at the same time during pregnancy.

Causes and mechanisms of pathogenesis 

Favorable cause

During pregnancy, especially in the last 3 months, the uterus is usually tilted to the right and will press on the ureter and the right kidney, so it is easy to cause fluid retention and kidney inflammation.

In the postpartum period, some women often have urinary retention caused by the birth, such as not having urinate first for pregnant women; Urinary retention can also be caused by reflex nerves due to injury to the lower genital tract, Forceps procedure, smoking sensation, gestational hyperactivity ... or sometimes due to using many drugs and these drugs. have anti-diuretic effect during childbirth and if after giving birth, do not use drugs to increase the increase further makes urine pass out faster. Or, using urinary catheterization before, during, and after birth does not guarantee sterility, so urinary tract infections are more likely to occur. Failure to pass urine before delivery will cause the bladder to expand, causing urine to stagnate, and infection has a chance.

Mechanism of pathogenesis

During pregnancy, the hormonal, neurologic, and physiological changes that form a mechanism of urinary infection such as Progesterone under the influence of pregnancy will cause bowel movements, urinary peristalsis. The reduction in management leads to more frequent constipation and stagnation of urine.

Clinical and therapeutic measures 

Depending on the anatomical site of an infection, the following clinical forms may be encountered:

Urinary tract infection has no symptoms

Rate of infection:

Depends on the number of births. The more you give birth, the more likely you are to get urinary tract infections.

Depending on socio-economic conditions: poor pregnant women, difficult economic circumstances, poor hygiene ... are susceptible to urinary infections.

Diagnostic symptoms:

Based on subclinical tests only: Culture of bacteria on mid-stream urine samples (through the urine) of pregnant women: If there are more than 100,000 bacteria/ml of urine, it can be concluded that urinary infection has no symptoms proof.

Effects on pregnancy:

Some authors find that approximately 25% of asymptomatic urinary infections lead to symptomatic urinary tract infections. This pattern often leads to premature birth or poor fetal development in the uterus.


A 10-day course of antibiotic treatment is required. One of the following drugs can be used:

Nitrofurantoin (Macrodantin) 100mg once daily.

Nibiol 100mg x 6 tablets / day in 3 divided doses (oral).

Ampicillin or Cephalosporin 2gam / day in 4 divided doses.

Sulfisoxazole (Gantrisin) 1gam / day in 4 divided doses.

Urethritis - Cystitis

Diagnostic symptoms

Common symptoms such as painful urination (often blurred at the end of the line), urinary incontinence, difficulty urinating, frequent urination (small amount of urine and forced women to urinate each time urinating).

In addition, urine sediment can be tested: it contains pus, bacteria, and red blood cells in the field.

Effects on pregnancy:

There are often few complications but can still lead to pregnancy, miscarriage, especially in the first months of pregnancy.


Using a course of antibiotics for 10 days should use specific antibiotics if used according to the antibiotic map as possible. The results of treatment are usually good if only a urethral or bladder infection is present.

Commonly used antibiotics:

Nitrofurantoin (Macrodantin) 100mg once daily.

Nibiol 100mg x 6 tablets / day in 3 divided doses (oral).

Ampicillin or Cephalosporin 2gam / day in 4 divided doses.

Sulfisoxazole (Gantrisin) 1gam / day in 4 divided doses.

If the urine culture is negative, still treat in the above direction if there are obvious symptoms above (painful urination, urinary incontinence, difficulty urination, repeated urination ...) and other causes such as Chlamydia Trachomatis can be thought. This type of cause can be used with antibiotics Erythromycin 2gam / day for 10 days.

Acute pyelonephritis


This is a severe form of urinary tract infection in pregnancy that is common in the next 20 weeks of pregnancy, the most common cause is urinary infection from downstream upstream (according to the ureter). Clinically, the following symptoms are common:

Occurs suddenly in a normal woman or can be seen in women who have had urethritis or pre-existing cystitis. Symptoms help diagnose:

Urinary pain, difficulty urination, hematuria.

Fever, chills, fever are often high, possibly 40 ° C.

Pain in one hip or both sides (at examination).

Poor appetite or loss of appetite.

Nausea, or vomiting.

A urine test for sediment cells results in urine containing many bacteria, white blood cells, and capsules. The bacteria that cause disease can be Gram (negative) or Gram (positive) such as Escherichia Coli (80%), Klebsiella, Pneumonia, Enterobacter, Proteus...

Differential diagnosis with:

Pain caused by uterine contractions (with labor).


Young vegetables.

Necrotic fibroids.

Microbial infection in the postpartum period.

Effects on pregnancy:

Often leads to premature delivery, fetal death in the uterus if the diagnosis is late and treatment is inactive.

Treatment and care:

Absolutely rest in bed.

Infusion and monitoring of urine volume to assess kidney function and early manifestations of diffuse urinary infections.

More monitoring of blood pressure, pulse, temperature.

Treatment of antibiotics with broad-spectrum resistance such as Axon, Cefomic, Trizon ... or can be used in combination with Ampicillin (or P√©nicilline) high doses with Gentamycin. Observe carefully in the first 2 days of treatment. If the above clinical symptoms decrease or disappear, further treatment is required for up to 10 days. If after 2 days of follow-up (despite the active use of antibiotics) there is no symptom improvement, the antibiotic should be changed based on the antibiotic results.

It may be necessary to surgically remove urinary stones or to release Abces around the kidney if the patient's condition gets worse and through the subclinical detection of the aforementioned diseases.

Chronic pyelonephritis


You may experience urethritis, cystitis, or acute pyelonephritis.

Clinical symptoms:

Often, clinical symptoms only manifest impaired renal function (renal failure) when the disease is too severe.

Effects on pregnancy and pregnant women:

The prognosis of the disease usually depends on the degree of damage to the kidneys. Often the prognosis is bad for mothers with kidney failure. If the kidney function is good, blood pressure is still within the normal range, people find that the fetus is still developing normally like other women.


Treat such as acute nephritis, but careful attention should be paid to renal function. Sometimes it is possible to combine hemodialysis if the conditions and the right indications are met.


Need early diagnosis and aggressive treatment of urinary tract infections in pregnancy to avoid many adverse complications harmful to both mother and fetus. So need to manage pregnancy well. In addition, during the examination and management process, it is necessary to avoid favorable factors causing urinary tract infections such as obstetric trauma, urinary retention, which should be limited if deemed not necessary. In addition, it is necessary to treat inflammation of the vulva, vagina, cervix during pregnancy to prevent urinary tract infections.