Macrosomic Babies

EDITORIAL COMMENT: This paper presents the useful information that shoulder dystocia associated with macrosomia is more likely to result in neonatal morbidity when instrumental delivery is necessary than when delivery is spontaneous; whether or not this important conclusion applies equally to nulliparas and multiparas cannot be evaluated from the data presented here where only 17 of the 93 patients delivered vaginally required forceps delivery. In the editor's opinion mid‐forceps delivery is likely to be followed by shoulder dystocia when macrosomia is associated with occipitoposterior position in either nulliparas or multiparas. One reviewer of this paper was uneasy that in the presence of suspected macrosomia, Caesarean section rather than forceps delivery should be performed. If the head is arrested in the mid‐pelvis the risk of shoulder dystocia is considerable. Trial of forceps in theatre does not provide an easy solution because the greater problem may prove to be the shoulders when, in spite of some articles to the contrary, one is committed to vaginal delivery once the head is born. Another consideration is the type of analgesia used for such forceps deliveries ‐ in the editor's opinion mid‐forceps delivery merits general anaesthesia when there is the possibility of macrosomia, to provide ideal conditions for assessment and forceps rotation and delivery, and dealing with impacted shoulders if this complication occurs. A final comment is to remember the advice we received in training to ‘beware of mid‐forceps delivery in a multipara’ and this is especially true if she has previously required mid‐forceps delivery and/or has delivered an infant with birth‐weight above 4,000–4,500g. (see previous comments on Shoulder Dystocia Aust NZ J Obstet Gynaecol 1988; 28: 107 and 1989; 29: 129). Summary: A review on 3,241 delivery records was made to study the obstetrics and the neonatal outcomes of 129 macrosomic (>4,000g) babies. They were found to have a nearly 6‐fold increase in the neonatal morbidity rate compared with normosomic babies. The emergency Caesarean section rate for nulliparas and parous women with macrosomic babies was 41.3% and 8.4% respectively. Among macrosomic babies, shoulder dystocia was not associated with maternal stature, induction of labour, use of oxytocin or abnormal labour patterns, but was associated with instrumental delivery. Macrosomic babies with shoulder dystocia after instrumental delivery had a higher neonatal morbidity rate than those delivered spontaneously.