Screening for Low-Tract Genital Infections in Women with Threatened Preterm Labor: Which Role?

OBJECTIVES: The aim of this study was to evaluate the possible relationship between cultural specimens and preterm birth in women admitted for threatened preterm labor. Preterm birth is the leading cause of neonatal mortality and antenatal hospitalization; several risk factors including intrauterine infections have been identified, but its real causes remain poorly understood. DESIGN: This is a retrospective, multicenter, cohort study including 250 women admitted for threatened preterm labor. Methods, Participants/Materials, Setting: All women admitted for threatened preterm labor, i.e., presenting with cervical changes and uterine activity before 37 weeks at the obstetrics unit of the hospitals of Modena, Monza, Carate, and Vimercate were included in the study. We excluded twin pregnancies and cases with preterm premature rupture of membranes at admission. Data about maternal history, pregnancy complications, cervical length, vaginal swabs, and urine culture at admission and gestational age at delivery were collected from clinical records in order to compare the incidence of preterm birth according to some known risk factors, cervical length, and microbiological test at admission. RESULTS: 250 women were included in the study; preterm birth at less than 37 weeks occurred in 44.4% women admitted for threatened preterm labor. The incidence of preterm birth was not different between those with a positive or a negative vaginal swab (48.3 vs. 38.4%, p = 0.22) or positive versus negative urine culture (31.8 vs. 42.1%, p = 0.23) at admission. A shorter cervical length at admission was found in women with subsequent preterm birth (17 vs. 19.5 mm, p = 0.03). Cervical length <15 mm (OR 1.82, 95% CI: 1.03-3.23, p = 0.039) predicted the risk of preterm birth. Furthermore, only the history of a previous preterm birth (p = 0.02) and a previous uterine curettage (p = 0.045) was associated with preterm birth. LIMITATIONS: The observational and retrospective nature of the study and its small sample size are important limitations of the study. Moreover, women were not systematically or randomly assigned to the screening for vaginal or urinary infections. CONCLUSIONS: There is no evidence that the search for vaginal or urinary infections in women admitted for threatened preterm labor is helpful to identify those at increased risk of preterm birth. Although several studies have explored the role of screening for bacterial vaginosis in asymptomatic women and some studies evaluated vaginal or urinary infections in women with preterm birth, none of them focused on the possible role of microbiological specimens as a predictive tool in women admitted for threatened PTL. No association was found in our study, but prospective randomized controlled trials are required to confirm the results of this observation.

Operative vacuum vaginal delivery: effect of compliance with recommended checklist.

PURPOSE: Even if the prerequisites and the technique of vacuum extraction are largely established, the role of a checklist in this field has not been tested. To evaluate the role of a checklist implementation on the compliance with the recommended rules in operative vacuum vaginal delivery (OVD) and on maternal and perinatal outcomes. MATERIALS AND METHODS: Retrospective cohort study on OVD between January 2012 and December 2015 at two hospitals with a tradition of teaching of OVD. A checklist for OVD was introduced in 2014. Three rules had to be recorded: fetal head station and position determination, no more than four tractions, and no more than three cup applications. Adverse maternal outcomes included third- and fourth-degree perineal tears. Adverse neonatal outcome included asphyxia, need for neonatal resuscitation, NICU admission, major head injuries, scalp injuries, and bone or brachial plexus injuries. RESULTS: Introduction of a checklist for OVD resulted in an increase in the compliance with the rules (83.3 versus 62.8%, p < .001). Cases in which the rules were respected had lower incidence of third- and fourth-degree perineal lacerations after controlling for episiotomy, nulliparity, and indication for OVD (OR = 0.4, 95% CI 0.18-0.89), but similar rates of failure of OVD (2.1 versus 2.2%, p = 1) and adverse neonatal outcome (10.8 versus 11.7%, p=.71). CONCLUSION: Knowledge and documented compliance with a checklist of recommended rules in OVD may assist in achieving a lower rate of severe perineal and anal sphincter injury but does not alter the success of the procedure or neonatal outcome.

Is perinatal asphyxia predictable?

BACKGROUND: The objective of our study was to evaluate the association between perinatal asphyxia and hypoxic-ischemic encephalopathy (HIE) with the presence of ante and intrapartum risk factors and/or abnormal fetal heart rate (FHR) findings, in order to improve maternal and neonatal management. METHODS: We did a prospective observational cohort study from a network of four hospitals (one Hub center with neonatal intensive care unit and three level I Spoke centers) between 2014 and 2016. Neonates of gestational age ≥ 35 weeks, birthweight ≥1800 g, without lethal malformations were included if diagnosed with perinatal asphyxia, defined as pH ≤7.0 or Base Excess (BE) ≤ - 12 mMol/L in Umbical Artery (UA) or within 1 h, 10 min Apgar < 5, or need for resuscitation > 10 min. FHR monitoring was classified in three categories according to the American College of Obstetricians and Gynecologists (ACOG). Pregnancies were divided into four classes: 1) low risk; 2) antepartum risk; 3) intrapartum risk; 4) and both ante and intrapartum risk. In the first six hours of life asphyxiated neonates were evaluated using the Thomson score (TS): if TS ≥ 5 neonates were transferred to Hub for further assessment; if TS ≥ 7 hypothermia was indicated. RESULTS: Perinatal asphyxia occurred in 21.5‰ cases (321/14,896) and HIE in 1.1‰ (16/14,896). The total study population was composed of 281 asphyxiated neonates: 68/5152 (1.3%) born at Hub and 213/9744 (2.2%) at Spokes (p < 0.001, OR 0.59, 95% CI 0.45-0.79). 32/213 (15%) neonates were transferred from Spokes to Hub. Overall, 12/281 were treated with hypothermia. HIE occurred in 16/281 (5.7%) neonates: four grade I, eight grade II and four grade III. Incidence of HIE was not different between Hub and Spokes. Pregnancies resulting in asphyxiated neonates were classified as class 1) 1.1%, 2) 52.3%, 3) 3.2%, and 4) 43.4%. Sentinel events occurred in 23.5% of the cases and FHR was category II or III in 50.5% of the cases. 40.2% cases of asphyxia and 18.8% cases of HIE were not preceded by sentinel events or abnormal FHR. CONCLUSIONS: We identified at least one risk factor associated with all cases of HIE and with most cases of perinatal asphyxia. In absence of risk factors, the probability of developing perinatal asphyxia resulted extremely low. FHR monitoring alone is not a reliable tool for detecting the probability of eventual asphyxia.

Amnioreduction.

Pregnancies complicated by hydramnios are at increased risk of both maternal and fetal complications. Since amniotic pressure is elevated in polyhydramnios, it has been suggested that the complications may be mediated by anomalies connected with amniotic pressure. The rationale behind amnioreduction is thus to restore normal amniotic pressure by draining a large amount of amniotic fluid volume in order to reduce maternal discomfort, improve uteroplacental perfusion, and prolong pregnancy by limiting the risk of preterm labour and rupture of the membranes. The procedure has a complication rate in terms of spontaneous premature rupture of membranes, abruptio placenta, or chorioamnionitis, regardless of the technique adopted.

Nitrous oxide amniodistention compared with fluid amniodistention reduces operation time while inducing no changes in fetal acid-base status in a sheep model for endoscopic fetal surgery.

OBJECTIVE: Our purpose was to evaluate in a sheep model for endoscopic fetal surgery the impact of nitrous oxide-gas amniodistention compared with fluid amniodistention on duration of surgery, hemorrhagic events, and fetomaternal acid-base status. STUDY DESIGN: Pregnant ewes (n = 16) at 92 to 104 days of gestation (term, 145 days) underwent amniodistention with Hartmann's solution (group I, n = 8) or nitrous oxide (group II, n = 8) at 38 degrees C. Endoscopic tracheal clipping according to a standardized surgical protocol was performed in all animals. The duration of fetoscopy (from insertion of first cannula until removal of last one), fetal surgery (fetal skin incision to skin closure), and number of bleeding episodes was recorded. Maternal and fetal blood gas values (pH, PO2, and PCO2) were measured at baseline and every 15 minutes during the experiment. Videotapes of the operations were assessed independently and scored by a visual analog scale in terms of smoothness of the operation and control of hemorrhagic events. RESULTS: Mean duration of fetoscopy (+/-SEM) (68 +/- 16 minutes vs 92 +/- 23 minutes) and fetal surgery (19 +/- 6 minutes vs 42 +/- 18 minutes) as well as number of bleeding episodes (1.9 +/- 0.8 minutes vs 5.8 +/- 2.1 minutes) was significantly reduced in animals operated with use of nitrous oxide amniodistention. In both groups, fetal and maternal blood gases remained unchanged during the entire experiment. Visual analog scale (VAS) scores were significantly higher for procedures conducted with use of gas distention. CONCLUSION: In a lamb model for fetal surgery, gas amniodistention with use of nitrous oxide results in a quicker operation procedure with less bleeding compared with fluid amniodistention, and without adverse side effects on fetomaternal acid-base status.

Ex vivo testing of a temperature- and pressure-controlled amnio-irrigator for fetoscopic surgery.

BACKGROUND: Currently, amnioinfusion fluids used in operative fetoscopy usually are preheated to body temperature. As the complexity of procedures increases, purposed designed devices should be designed that allow control of pressure and temperature during amnioinfusion or amnioexchange. In the current study, a prototype amnio-irrigator and fluid heater were evaluated. METHODS: The medical fluid heater heats fluid by conduction up to 37 degrees C. The maximum irrigation pressure and flow rates can be preset. Actual irrigation pressure (0 to 30 mm Hg) and flow rate (0 to 300 mL/min) can be read on the front panel. A series of ex vivo experiments were set up to determine the relationship between the flow rate (FR) and lumen of the instruments as well as the maximum flow rate (MFR) with and without the pressure control. Further, the relationship between FR and the irrigation pressure (IP) was determined. In an artificial pseudoamniotic sac the relationship between FR and change in temperature was measured, with and without the use of the medical fluid heater. RESULTS: When the IP was limited to 24 mm Hg, FR and pressure were correlated (r = 0.34; P <.001). The larger the functional lumen of the fetoscopic instrumentation, the higher the flow (r = 0.43; P <.001) and the lower the increase in IP (r = -0.47; P <.001). A quadratic relation between flow and temperature was observed both for preheated fluid as when using the fluid heater (r(2) = 0.71 and r(2) = 0.88; P <.001). However, at low flow rates, a thermal decrease of over 3 degrees C was observed when the fluid heater was not used. CONCLUSIONS: The current study quantifies an expected relationship between the diameter of the irrigation channel and achievable flow rates. It also shows that a medical fluid heater is needed when strict control of temperature would be desired.