Short-term variation of the fetal heart rate as a marker of intraamniotic infection in pregnancies with preterm prelabor rupture of membranes: a historical cohort study.

INTRODUCTION: Intraamniotic infection (IAI) and subsequent early-onset neonatal sepsis (EONS) are among the main complications associated with preterm prelabor rupture of membranes (PPROM). Currently used diagnostic tools have been shown to have poor diagnostic performance for IAI. This study aimed to investigate whether the exposure to IAI before delivery is associated with short-term variation of the fetal heart rate in pregnancies with PPROM. METHODS: Observational cohort study of 678 pregnancies with PPROM, delivering between 24 + 0 and 33 + 6 gestational weeks from 2012 to 2019 in five labor units in Stockholm County, Sweden. Electronic medical records were examined to obtain background and exposure data. For the exposure IAI, we used the later diagnosis of EONS in the offspring as a proxy. EONS is strongly associated to IAI and was considered a better proxy for IAI than the histological diagnosis of acute chorioamnionitis, since acute chorioamnionitis can be observed in the absence of both positive microbiology and biochemical markers for inflammation. Cardiotocography traces were analyzed by a computerized algorithm for short-term variation of the fetal heart rate, which was the main outcome measure. RESULTS: Twenty-seven pregnancies were categorized as having an IAI, based on the proxy diagnosis of EONS after birth. Fetuses exposed to IAI had significantly lower short-term variation values in the last cardiotocography trace before birth than fetuses who were not exposed (5.25 vs 6.62 ms; unadjusted difference: -1.37, p = 0.009). After adjustment for smoking and diabetes, this difference remained significant. IAI with a later positive blood culture in the neonate (n = 12) showed an even larger absolute difference in STV (-1.65; p = 0.034), with a relative decrease of 23.5%. CONCLUSION: In pregnancies with PPROM, fetuses exposed to IAI with EONS as a proxy have lower short-term variation of the fetal heart rate than fetuses who are not exposed. Short-term variation might be useful as adjunct surveillance in pregnancies with PPROM.

Reference values for Lactate Pro 2™ in fetal blood sampling during labor: a cross-sectional study.

OBJECTIVE: Lactate Pro™ (LP1) is the only lactate meter evaluated for fetal scalp blood sampling (FBS) in intrapartum use. The reference values for this meter are: normal value <4.2 mmol/L, preacidemia 4.2-4.8 mmol/L, and acidemia >4.8 mmol/L. The production of this meter has been discontinued. An updated version, Lactate Pro 2TM (LP2), has been launched and is shown to be differently calibrated. The aims of the study were to retrieve a conversion equation to convert lactate values in FBS measured with LP2 to an estimated value if using LP1 and to define reference values for clinical management when using LP2. STUDY DESIGN: A cross-sectional study was conducted at a university hospital in Sweden. A total of 113 laboring women with fetal heart rate abnormalities on cardiotocography (CTG) had FBS carried out. Lactate concentration was measured bedside with both LP1 and LP2 from the same blood sample capillary. A linear regression model was constructed to retrieve a conversion equation to convert LP2 values to LP1 values. RESULTS: LP2 measured higher values than LP1 in all analyses. We found that 4.2 mmol/L with LP1 corresponded to 6.4 mmol/L with LP2. Likewise, 4.8 mmol/L with LP1 corresponded to 7.3 mmol/L with LP2. The correlation between the analyses was excellent (Spearman's rank correlation, r=0.97). CONCLUSION: We recommend the following guidelines when interpreting lactate concentration in FBS with LP2: <6.4 mmol/L to be interpreted as normal, 6.4-7.3 mmol/L as preacidemia indicating a follow-up FBS within 20-30 min, and >7.3 mmol/L as acidemia indicating intervention.

[Acute abdominal pain caused by acute intermittent porphyria - case report and review of the literature]. / Bráoir kvioverkir af völdum slitróttrar bráoaporfýríu- sjúkratilfelli og yfirlit.

We describe a case of acute intermittent porphyria in a woman who presented repeatedly with abdominal pain. Porphyrias are caused by decreased enzyme activity in the heme biosynthetic pathway leading to overproduction of heme precursors if demand increases. This can cause symptoms such as abdominal pain, nausea and vomiting, constipation, tachycardia and hypertension. Treatment includes removal of causative factors, administration of carbohydrates or hemin to reduce the production of heme precursors as well as symptomatic treatment.

[Vaginal birth after one previous cesarean section]. / Faeding eftir fyrri faedingu med keisaraskurdi.

OBJECTIVE: To evaluate the frequency of different modes of delivery after one previous cesarean section and those factors which may influence mode of delivery. MATERIAL AND METHODS: During the study period (1.1.2001-31.12.2005) 925 women with a previous cesarean section and a following singleton pregnancy were identified and included. Information regarding mode of delivery, induction of labor, instrumental delivery, the urgency and indications for first and second cesarean section, birth weight and Apgar scores were collected retrospectively. RESULTS: Trial of labor (TOL) was initiated for 564 women of which 61% were successful while 39% delivered by an emergent cesarean section. In total, 346 women delivered vaginally (37%), 341 women (37%) delivered with an elective cesarean section and 238 (26%) underwent an emergency cesarean section. The VBAC rate increased during the study period, from 35% to 46%. Women who underwent an elective cesarean section due to fetal malpresentation (most often breech) in their first pregnancy were significantly more likely to have a successful VBAC in their second pregnancy (53%) compared with women who had an elective cesarean section for any other indication (21%) (p<0.0001). Uterine rupture occurred in six women (1%) during TOL, five underwent an emergency cesarean section and had healthy infants while there was one intrapartum fetal death. No correlation was found between birth mode and Apgar scores at five minutes. Perinatal mortality rate was 5,4 per thousand. Trial of labor was less likely to succeed if the infant's birth weight was >4000 grams compared with <4000 grams (p<0.01). CONCLUSION: The results of this study indicate that VBAC is a safe option for women with a history of one previous cesarean section while in the hospital setting where there are resources for an immediate cesarean section. KEYWORDS: Vaginal birth after cesarean section (VBAC), uterine rupture, perinatal mortality rate. Correspondence: Hildur Hardardóttir, hhard@landspitali.is.