The role of obstetric factors in determining fetal viability.

OBJECTIVE

To study the influence of primary obstetric complications on the survival and short-term morbidity rates of very-low-birth-weight (VLBW) babies.

DESIGN

A 1-year retrospective, descriptive study.

SETTING

Department of Obstetrics and Gynaecology, Tygerberg Hospital, CP.

STUDY POPULATION: 257 women admitted with live singleton fetuses and who eventually delivered babies with birth weights ranging from 750 to 1,499 g.

MANAGEMENT: Primary obstetric complications responsible for the delivery of the VLBW babies were clinically diagnosed. Active management was undertaken if the fetus was viable and obstetric and neonatal resuscitation were applied. Management was conservative when the fetus was considered non-viable. This decision on the initial treatment option was taken by the obstetrician who managed the case.

MAIN OUTCOME MEASUREMENTS: Survival and short-term morbidity rates of the babies.

RESULTS

Spontaneous preterm labour (45%) and hypertensive disorders (39%) were equally responsible for delivery of VLBW babies at Tygerberg Hospital. The only obstetric factor influencing the babies' outcome, however, was the initial management decision by the obstetrician. There was a survival rate of 160/213 (75.1%) in the actively managed group compared with only 1/44 (2.3%) in the conservatively managed group. Other factors that significantly influenced neonatal survival of VLBW babies were: birth weight, gestational age, Apgar score at 5 minutes and length of time between admission to hospital and the delivery.

CONCLUSION

The obstetric complication responsible for delivery of the VLBW baby did not influence the survival rate. The major determinant of neonatal survival was the obstetrician's decision to manage the fetus either actively or conservatively. It seems that the outcome of VLBW babies is influenced primarily by the intrinsic characteristics of the neonates' gestational age, birth weight and condition at birth, and not the reason for delivery.