Background: Cardiotocography (CTG) is a widely used method for assessing fetal wellbeing during labor. It is well-known that CTG has high sensitivity but low specificity. To avoid unnecessary operative interventions, adjunctive methods such as fetal blood sampling (FBS) are used. Few studies have looked into whether FBS can be used during second stage of labor, and in that case, which of the methods (lactate or pH) are preferred. Objective: To evaluate clinical effectiveness of measuring lactate versus pH in preventing birth acidemia when FBS was performed during second stage of labor. Methods: Secondary analysis of a randomized controlled trial. Thousand three hundred and thirty-eight women with a singleton pregnancy, cephalic presentation, gestational age 34 weeks, and indication for FBS during second stage of labor were included. Main outcome measures: Metabolic acidemia (pH <7.05 and base deficit >12 mmol/l) or pH < 7.00 in cord arterial blood at birth. Secondary outcomes: A composite outcome (metabolic acidemia, pH <7 or Apgar score <4), and rates of operative deliveries. Results: Metabolic acidemia occurred in 4.1% in the lactate versus 5.1% in the pH group (relative risk (RR): 0.80; 95% confidence interval (CI): 0.48-1.35) and pH <7 in 1.4% versus 2.8% (RR: 0.51, 95% CI: 0.23-1.13). Composite outcome was found in 3.8 versus 4.9%, respectively (RR: 0.76; 95% CI: 0.46-1.26). No difference in total operative interventions was found. More cesarean deliveries were performed in the lactate group (16.5 vs. 12.4%; RR: 1.33; 95% CI: 1.02-1.74). Conclusion: When analyzing lactate or pH in fetal scalp blood during second stage of labor neonatal outcomes were comparable. The frequency of total operative interventions was similar but more cesarean deliveries were performed in the lactate group.

However, because initial concerns were raised in the 1990s, the risks associated with indomethacin have appeared to be low, and the use of this tocolytic, given its effectiveness, has gradually increased.Use of any medication is a risk/benefit calculation, and with TTTS, even after laser therapy, the risks remain very high. Although minimally invasive in utero approaches are relatively safe, the uterus does not appreciate intrusions, and contractions, chorioamnion separation, premature rupture of the membranes, and PTB are common. Conclusions that can be drawn from this article are limited given that the treatment was used at one site and not the other, and there are undoubtedly other differences in the populations and in other aspects of care. However, the data are certainly thought provoking that long-term indomethacin should at least be considered after laser treatment for TTTS. Although the association of indomethacin with neonatal complications is likely to be real, the risks are relatively small, whereas the risks of TTTS are extremely high. If indomethacin truly prolongs pregnancy by a substantial length of time, this would appear to outweigh potential risks. Studies of indomethacin have generally focused on very high-risk infants whose pregnancies fail tocolysis; those in whom labor is successfully halted likely have a different outcome. Although a randomized trial would be ideal, that will require large numbers of patients treated for TTTS and is unlikely to happen. In the meantime, use of this postsurgical treatment for at least some extended period seems reasonable.-MEN)