Risk factors for intrapartum acidemia - a cohort study

Umbilical arterial lactate levels after normal vaginal and elective cesarean delivery: The role of a longer active second stage most significant in high levels after vaginal delivery

AIM

To evaluate umbilical arterial lactate concentrations after spontaneous vaginal delivery and after elective Cesarean delivery, and to study the simultaneous effects of maternal and obstetric variables in high lactate levels in vaginally delivered healthy term singletons.

METHODS

The birth register study included information about the umbilical artery lactate values and clinical perinatal data from 7723 women and their singleton newborns (7301 spontaneous vaginal and 422 elective cesareans) from Kuopio University Hospital, Finland. High lactate levels were evaluated more extensively among healthy term neonates (N = 6541), to evaluate high levels after normal vaginal labors.

RESULTS

The mean lactate level was significantly lower after elective cesarean compared to vaginal delivery (2.42 [0.94] vs. 3.56 [1.62] mmol/l; p < 0.0001). Consequently, the 90th percentile limit values were 3.60 and 5.80 mmol/L. Among healthy term newborns born vaginally, higher lactate values (≥5.80 mmol/L) were independently associated with a longer duration of the active second stage of labor (ORs 1.91-10.97) and duration of ruptured fetal membranes (ORs 1.36-2.46), higher gestational age at birth (ORs 1.41-1.86), null parity (OR 2.17), maternal infection (OR 1.81) and short maternal stature (OR 1.45). We report 90th/95th limits for umbilical arterial lactate values in relation to the various durations of labors for term newborns who are delivered by the vaginal route.

CONCLUSIONS

Even though the high umbilical lactate levels may indicate serious birth asphyxia, levels after vaginal birth reflect the physiological stress and subclinical transient asphyxia frequently seen in normal vaginal deliveries.

Umbilical cord arterial blood gas analysis in term singleton pregnancies: a retrospective analysis over 11 years

Objective

Given that the large volume of data on cord arterial blood gas analysis (ABGA) have been rarely addressed in Korean population, we aimed to examine the incidence, associated factors, and neonatal outcomes in cases of low cord pH, and investigate the incidence of cerebral palsy (CP).

Methods

From data of all consecutive term singleton pregnancies delivered in our institution from 2006 to 2016 (n=15,701), cases with cord ABGA (n=14,221) available were included. We collected information on maternal clinical characteristics and delivery outcomes and also examined neonatal and infant outcomes, including neonatal intensive care unit (NICU) admission and CP, in cases with low cord pH, defined as a pH <7.1.

Results

Rates of low Apgar scores at 1 minute (<4) and 5 minutes (<7) were 0.6% (n=79) and 0.4% (n=58), respectively. Rates of cord pH <7.2, <7.1, and <7.0 were 7.1% (n=1,011), 1.1% (n=163), and 0.3% (n=38), respectively. Among cases with low cord pH, 30.1% (n=49/163) were admitted to the NICU and 11.0% (n=18/163) required ventilator support. Ultrasonography of the brain was performed in 28.8% (n=47/163), with abnormal findings observed in 27.7% (n=13/47). Among cases with low cord pH, 1.8% (n=3/163) were subsequently diagnosed with CP, including 2 cases of spastic CP and 1 of ataxic CP.

Conclusion

Although low cord pH was a relatively frequent finding observed in 1 out of every 87 cases, hypoxic-ischemic encephalopathy-related CP was found in only 1 out of 7,111 term singleton deliveries over 11 years in our institution.