Abstract

OBJECTIVE
To analyse whether the increase in lactate in response to intrapartum hypoxia differs between small- (SGA), appropriate- (AGA) and large-for-gestational-age (LGA) fetuses.
DESIGN
Observational cohort study.
SETTING
Ten obstetric units in Sweden.
POPULATION
A cohort of 1496 women.
METHODS
A secondary analysis of a randomised controlled trial, in which 1496 women with fetal heart rate abnormalities, indicating fetal scalp blood sampling, were randomised to lactate analyses. After delivery, the neonates were divided according to birthweight for gestational age into SGA, AGA and LGA groups.
MAIN OUTCOME MEASURE
Lactate concentration in fetal scalp blood.
SECONDARY OUTCOME MEASURES
Acid-base balance in cord artery blood and Apgar score <7 at 5 minutes.
RESULTS
Median lactate concentrations in the SGA, AGA and LGA groups were 3.8, 3.0 and 2.2 mmol/l, respectively (SGA versus AGA, P = 0.017; LGA versus AGA, P = 0.009). In the subgroups with scalp lactate >4.8 mmol/l (lactacidaemia), the corresponding median (range) values were 6.2 (4.9-14.6), 5.9 (4.9-15.9) and 5.7 mmol/l (5.0-7.9 mmol/l), respectively (no significant differences between the groups). The proportions of neonates with cord artery pH < 7.00, metabolic acidaemia or Apgar score <7 at 5 minutes were similar in all weight groups.
CONCLUSION
SGA fetuses with fetal heart rate abnormalities have the same ability to produce lactate as a response to intrapartum hypoxia as AGA and LGA fetuses. The risk of a poor outcome associated with high lactate concentration is the same in SGA, AGA and LGA fetuses. Scalp blood lactate analysis is therefore a reliable method for intrapartum fetal surveillance of suspected growth-restricted fetuses scheduled for vaginal delivery at ≥ 34 weeks of gestation.

Links

Publisher Full Text

Authors

Holzmann M, Cnattingius S, Nordström L

Institution

Department of Women's and Children's Health, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden. malin.holzmann@ki.se

Source

BJOG : an international journal of obstetrics and gynaecology 119:10 2012 Sep pg 1265-9

MeSH

Acidosis, Lactic
Adult
Birth Weight
Female
Fetal Blood
Fetal Growth Retardation
Fetal Hypoxia
Gestational Age
Humans
Hydrogen-Ion Concentration
Infant, Newborn
Infant, Small for Gestational Age
Lactic Acid
Pregnancy
Prospective Studies
Scalp
Sweden
Young Adult

Pub Type(s)

Journal Article
Randomized Controlled Trial
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

22804901