Preterm birth by vacuum extraction and neonatal outcome: a population-based cohort study.
BACKGROUND
Very few studies have investigated the neonatal outcomes after vacuum extraction delivery (VE) in the preterm period and the results of these studies are inconclusive. The objective of this study was to describe the use of VE for preterm delivery in Sweden and to compare rates of neonatal complications after preterm delivery by VE to those found after cesarean section during labor (CS) or unassisted vaginal delivery (VD).


METHODS
Data was obtained from Swedish national registers. In a population-based cohort from 1999 to 2010, all live-born, singleton preterm infants in a non-breech presentation at birth, born after onset of labor (either spontaneously, by induction, or by rupture of membranes) by VD, CS, or VE were included, leaving a study population of 40,764 infants. Logistic regression analyses were used to calculate adjusted odds ratios (AOR), using unassisted vaginal delivery as reference group.


RESULTS
VE was used in 5.7% of the preterm deliveries, with lower rates in earlier gestations. Overall, intracranial hemorrhage (ICH) occurred in 1.51%, extracranial hemorrhage (ECH) in 0.64%, and brachial plexus injury in 0.13% of infants. Infants delivered by VE had higher risks for ICH (AOR = 1.84 (95% CI: 1.09-3.12)), ECH (AOR = 4.48 (95% CI: 2.84-7.07)) and brachial plexus injury (AOR = 6.21 (95% CI: 2.22-17.4)), while infants delivered by CS during labor had no increased risk for these complications, as compared to VD.


CONCLUSIONS
While rates of neonatal complications after VE are generally low, higher odds ratios for intra- and extracranial hemorrhages and brachial plexus injuries after VE, compared with other modes of delivery, support a continued cautious use of VE for preterm delivery.
Department of Women's and Children's Health, Division of Reproductive Health, Karolinska Institutet, Retzius väg 13, 171 77 Stockholm, Sweden. katarina.aberg@ki.se.
Katarina
K
Åberg
Mikael
M
Norman
Cecilia
C
Ekéus
D000328:Adult; D001720:Birth Injuries / Q000453:epidemiology*; D001917:Brachial Plexus / Q000293:injuries; D002585:Cesarean Section / Q000706:statistics & numerical data*; D015331:Cohort Studies; D005260:Female; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D020198:Intracranial Hemorrhage, Traumatic / Q000453:epidemiology*; D007743:Labor, Obstetric; D036801:Parturition; D011247:Pregnancy; D047928:Premature Birth / Q000453:epidemiology*; D012042:Registries; D012535:Scalp / Q000293:injuries; D012640:Seizures / Q000453:epidemiology; D013548:Sweden / Q000453:epidemiology; D014620:Vacuum Extraction, Obstetrical / Q000706:statistics & numerical data*; D055815:Young Adult