The anaerobic bacteria of the female genital tract in healthy women, both pregnant and nonpregnant, were investigated during the period from Jan. 1973 to May 1976. The study was based on findings observed in 802 women.
In the vagina, the effects of the various pH levels on the growth of anaerobes are of great importance. The percentage of successful bacterial isolation decreased as the state of vagina became clean. Fifty five of 104 (52.9%) specimens from healthy nonpregnant women with a pH range from 4.0 to 6.8 yielded anaerobes. As to the cleanliness and the isolation of anaerobes, Grade I (pH 4.0-4.6) showed 8.3%(3 of 36 cases), Grade II (pH 4.2-5.6) 64.9%(24 of 37 cases), Grade III (pH 5.6-6.8) 90.3%(28 of 38 cases).
During pregnancy, the much increased vaginal secretion is represented normally by a thick, white discharge. Its pH varied from 3.8 to 6.2 according to the increased production of lactic acid. In healthy pregnant women anaerobic bacteria were isolated from 54 of 120 cases (45.0%). As to the cleanliness and the isolation of anaerobes, Grade I (pH 3.8-4.6) showed 8.6%(3 of 35 cases), Grade II (pH 4.2-5.6) 44.2%(23 of 52 cases), Grade III (pH 5.6-6.2) 84.4%(28 of 33 cases). Thus, acidicpH played a significant role in keeping the vagina free of bacteria.
The normal Fallopian tubes were found to be completely free of bacteria in both pregnant and nonpregnant state.
Anaerobes were found rarely in the uterine cavity of the healthy nonpregnant women (7.1 %).
In pregnant and nonpregnant women, the lack of anaerobes in the normal cervical flora was in contrast to their high incidence in vagina, Anaerobes were found in cervical cultures from 20.7 per cent of nonpregnant women who had delivered previously with the contrast to 8.7 per cent of nonpregnant women who had never borne a child. During the third trimester of pregnancy in multiparas, anaerobes were isolated from 9 of 120cervical cultures (7.5%).
Comparison of the anaerobic bacteria isolated from the flora of the cervix and vagina showed that the organisms which constituted a large part of the vaginal flora were not necessarily observed in cervix.
Six samples of clear amniotic fluid obtained by abdominal amniocentesis and 18 samples obtained in the Cesarean Section without the rupture of the membrane were cultivated aerobically as well as anaerobically. No growth of organisms was observed.
On the contrary, of 19 amniotic fluid taken from patients (12 to 48 hours after the rupture of the membrane) 8 showed anaerobes (42.1%).
Without the rupture of the membrane, the anaerobic bacteria were found rarely even in the turbid amniotic fluid. In 35 cases anaerobes were isolated only in 2 (5.7%).
The anaerobic bacteria were present in large numbers in the external genitals of the healthy pregnant women. Therefore, the vaginal examinations late in pregnancy and the manipulations in labor are attended with danger to introduce bacteria into the genital tract.