The efficiency of the polymerase chain reaction (PCR) was compared with that of culture for detection of Ureaplasma urealyticum and Mycoplasma hominis in 726 clinical specimens comprising 189 gynecological samples, 362 urological samples, and 175 samples from newborn infants. The sensitivity of PCR versus culture was 95% for both organisms, while the sensitivity of culture versus PCR was 91% for Ureaplasma urealyticum and 84% for Mycoplasma hominis. Furthermore, PCR tests were faster than culture tests, allowing the time to diagnosis to be reduced from two to five days to 24 h.

The effects of Ureaplasma urealyticum colonization on pregnancy and neonatal outcome was prospectively studied in women with impending term or preterm delivery. One hundred and seventy women colonized with U. urealyticum as the only pathogenic microorganism and 83 women with negative cultures were enrolled for study. Compared to the controls, U. urealyticum colonization was associated with a significantly increased rate of amnionitis (2% vs 35%; p < 0.001), chorioamnionitis (0% vs 10%; p < 0.05), premature rupture of membranes (12% vs 35%; p < 0.001) and preterm delivery (10% vs 41%; p < 0.001). The rate of vertical transmission ranged from 38% in term infants to 95% in very low birth weight infants. U. urealyticum colonization at birth was associated with an increased risk for the development of respiratory distress syndrome (9% vs 51%), intraventricular hemorrhage (1% vs 7%) and bronchopulmonary dysplasia (4% vs 17%) in very low birth weight infants (< 1500 g). It is concluded that maternal U. urealyticum colonization is associated with amnionitis, chorioamnionitis and preterm delivery, and that tracheal colonization with U. urealyticum increases the risk for respiratory and neurological complications in very low birth weight infants.

Two different ventilation techniques were compared in a seven-centre, randomised trial with 181 preterm infants up to and including 32 completed weeks gestational age, who needed mechanical ventilation because of lung disease of any type. Technique A used a constant rate (60 cycles/min), inspiratory time (IT) (0.33s) and inspiratory: expiratory ratio (I:E) (1:2). The tidal and minute volume was only changed by varying peak inspiratory pressure until weaning via continuous positive airway pressure. Technique B used a lower rate (30 cycles/min) with longer IT (1.0 s). The I:E ratio could be changed from 1:1 to 2:1 in case of hypoxaemia. Chest X-rays taken at fixed intervals were evaluated by a paediatric radiologist and a neonatologist unaware of the type of ventilation used in the patients. A reduction of at least 20% in extra-alveolar air leakage (EAL) or death prior to EAL was supposed in infants ventilated by method A. A sequential design was used to test this hypothesis. The null hypothesis was rejected (P = 0.05) when the 22nd untied pair was completed. The largest reduction in EAL (-55%) was observed in the subgroup 31-32 weeks of gestation and none in the most immature group (< 28 weeks). We conclude that in preterm infants requiring mechanical ventilation for any reason of lung insufficiency, ventilation at 60 cycles/min and short IT (0.33 s) significantly reduces EAL or prior death compared with 30 cycles/min and a longer IT of 1 s. We speculate that a further increase in rate and reduction of IT would also lower the risk of barotrauma in the most immature and susceptible infants.

In this prospective study, the prevalence of the two Ureaplasma urealyticum biovars, parvo and T960, was determined in pregnant women and in gynecological patients colonized by ureaplasmas. Furthermore, we investigated the association of these biovars with gynecological complications and adverse pregnancy outcome. Isolates of U. urealyticum from 254 women were biotyped by a PCR method recently developed. The parvo biovar was found in 81% (206 of 254) of the patients, and the T960 biovar was found in 30% (76 of 254) of the patients; 6% (14 of 254) of the women were coinfected. Identical biovars were detected in mothers and their infants. Serial isolations or cultures from different sampling sites of the same individual revealed the same biovar. T960 was dominant in patients with pelvic inflammatory disease (57%) and patients who had had a miscarriage (42%), showed a higher rate of tetracycline resistance than did parvo isolates (55 versus 18%), and seemed to have more adverse effects on pregnancy outcome with regard to birth weight (2,500 versus 1,720 g), gestational age (35 versus 30 weeks), and preterm delivery (35 versus 77%).

The degree of colonization with Ureaplasma urealyticum correlates strongly with an adverse effect on pregnancy outcome.