Failed individual and sequential instrumental vaginal delivery: contributing risk factors and maternal-neonatal complications.
BACKGROUND
To identify the risk factors for failed instrumental vaginal delivery, and to compare maternal and neonatal morbidity associated with failed individual and sequential instruments used.


METHODS
A retrospective case-control study.


METHODS
From January 1995 to June 2001, there were 39 508 live births at >37 weeks' gestation of which 2628 (6.7%) instrumental vaginal deliveries were performed, 1723 (4.4%) were vacuum extractions and 905 (2.3%) were forceps. A total of 155/2628 (5.9%) patients who had failed instrumental delivery were matched with 204 patients who had successful instrumental delivery. The patients were divided into five groups. Group I (n = 129) had failed vacuum extraction, group II (n = 13) failed forceps, group III (n = 13) failed both (i.e. failed attempt at both instruments sequentially), group IV (n = 138) had successful vacuum extraction and group V (n = 66) successful forceps.


RESULTS
The failure rate for vacuum extractions 129/1723 (7.5%) was significantly higher than that for forceps 13/905 (1.4%) [odds ratio (OR) = 5.6, 95% CI 3-10.3]. There were no significant differences in all maternal complications (25.5% vs. 26.6%) between vacuum (groups I and IV) and forceps (groups II and V) assisted deliveries. There were more maternal complications in group III (46.2%) than in groups I (35.7%), II (23.1%) and V (27.3%) that did not reach statistical significance but were significantly higher than in group IV (15.9%, OR = 4.5, 95% CI 1.2-16.9). There was a significantly higher rate of all fetal complications in group III [11/13 (84.6%)] than in groups I [69/129 (53.5%)], II [7/13 (53.8%)], IV [35/138 (25.4%)] and V [22/66 (33.3%)] (OR = 4.8, 95% CI 0.9-19.9).


CONCLUSIONS
Applying the instrument at < or =0 fetal station, nulliparous women, history of previous cesarean section and fetal head other than occipitoanterior position were risk factors for failed instrumental delivery. Sequential use of instrumental delivery carries a significantly higher neonatal morbidity than when a single instrument is used.
Al-Kadri
Hanan
H
Department of Obstetrics and Gynecology, King Fahad National Guard Hospital, Riyadh, Saudi Arabia.
Sabr
Yasser
Y
Al-Saif
Saif
S
Abulaimoun
Bdair
B
Ba'Aqeel
Hassan
H
Saleh
Ahmed
A
D000328:Adult; D016022:Case-Control Studies; D036861:Delivery, Obstetric / Q000706:statistics & numerical data; D005113:Extraction, Obstetrical / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D007748:Labor Stage, Second; D008499:Medical Records; D007744:Obstetric Labor Complications / Q000453:epidemiology* / Q000209:etiology; D009772:Obstetrical Forceps / Q000009:adverse effects / Q000706:statistics & numerical data*; D016017:Odds Ratio; D010298:Parity; D011247:Pregnancy; D011256:Pregnancy Outcome; D012189:Retrospective Studies; D012307:Risk Factors; D012529:Saudi Arabia / Q000453:epidemiology; D017211:Treatment Failure; D014620:Vacuum Extraction, Obstetrical / Q000706:statistics & numerical data