Observations on the bacteriology of the urine and liquor in pregnancy and labour.

URINARY TRACT infections are now among the commonest bacterial infections. In England and Wales some 6,000 to 7,000 patients die every year from uraemia, about 3,000 of them between the ages of 5 and 55 years (Brit. med. J., 1967), and many of these die as the result of chronic urinary tract infection. Pregnant women are particularly prone to such infection both symptomatic and asymptomatic. These considerations have led to the recent widespread interest in the bacteriology of the urine in pregnancy. As the urine of the fetus is an important constituent of the amniotic fluid (Young and Martin, 1963), the bacteriology of the liquor amnii should reflect, to some extent, the condition of the urinary tract of the fetus. PATIENTS AND METHODS All the patients admitted to the Royal Maternity Hospital, Belfast are investigated for significant bacteriuria. Of the 1,300 patients admitted during the period of this study, 1,000 were antenatal and the remaining 300 were in labour. EXAMINATION OF URINE Early morning midstream specimens of urine were obtained from antenatal patients on the second day of admission to hospital and the specimens were examined within two hours of collection. Midstream or catheter specimens of urine were obtained on admission from patients admitted in labour and were refrigerated at 4°C until they could be cultured. Logarithmic dilutions of the urine were made in nutrient broth and 1 ml. from each dilution was transferred to a MacConkey plate which was incubated at 370 overnight. Significant bacteriuria in this study is defined as the presence of 100,000 (105) or more E. coli per ml. in two or more consecutive daily specimens of urine. The identity of E. coli was confirmed by standard biochemical tests (Cowan and Steel, 1965). SPECIMENS OF URINE AT VARIOUS TIMES OF THE DAY Four specimens of urine per day were obtained from each of 20 patients, 10 of whom had significant bacteriuria. As well as early morning urine, urine passed at 12 midday, 2.00 p.m. and 4.00 p.m. was examined and the count of E. coli per ml. of each specimen was recorded against its time of collection. All specimens were examined within two hours of collection. BAcTERIOLOGY OF LIQUOR AMNII Specimens of liquor amnii were obtained from 200 Rhesus negative patients of gestational periods of 28 to 34 weeks, who had amniocentesis performed during the period of this study. Of these, 10 had significant bacteriuria at the time of amniocentesis. Logarithmic dilutions of the liquor amnii were made in nutrient broth and 1 ml. from each dilution was transferred to a MacConkey plate and 1 ml. to blood agar plate. The plates were incubated at 37°C overnight.