Abstract：
OBJECTIVE: If a small for gestational age (SGA) foetus needs to be delivered because of severity (<3rd centile) attempting induction of labor theoretically increases the risk of caesarean section and neonatal acidosis, but these risks are poorly understood. This article aims to assess the risk of caesarean section and neonatal acidosis in attempted vaginal birth of a moderately preterm foetus in the setting of severe SGA.
METHODS: A single-centre hospital-based observational study conducted over a period of 17 consecutive years in mothers with a single foetus in cephalic presentation with severe SGA (<3rd centile) needing foetal extraction. Neonatal acidosis was considered moderate if pH<7.10 and severe if pH<7.0. The degree of severity of SGA was estimated according to the birth weight ratio.
RESULTS: Four hundred and thirty-four foetuses with severe SGA were included during the period, 140 of whom were born after induction (32.3%). In this group, 66.4% of women achieved a vaginal birth (66.4%; 95% CI [58.0-74.2]) and the risk of moderate or severe acidosis was doubled compared with the group of foetuses who had undergone a planned caesarean section (7.9% vs. 3.1%, OR=2.7 [1.1-6.7]). Neither gestational age nor the degree of growth restriction was significantly related to the risk of caesarean section or to the risk of moderate or severe neonatal acidosis.
CONCLUSIONS: In cases of severe SGA before 37weeks\' gestation, induction of labour allows vaginal delivery in two-thirds of cases. It is accompanied by a doubling of the risk of moderate or severe neonatal acidosis.
METHODS: A single-centre hospital-based observational study conducted over a period of 17 consecutive years in mothers with a single foetus in cephalic presentation with severe SGA (<3rd centile) needing foetal extraction. Neonatal acidosis was considered moderate if pH<7.10 and severe if pH<7.0. The degree of severity of SGA was estimated according to the birth weight ratio.
RESULTS: Four hundred and thirty-four foetuses with severe SGA were included during the period, 140 of whom were born after induction (32.3%). In this group, 66.4% of women achieved a vaginal birth (66.4%; 95% CI [58.0-74.2]) and the risk of moderate or severe acidosis was doubled compared with the group of foetuses who had undergone a planned caesarean section (7.9% vs. 3.1%, OR=2.7 [1.1-6.7]). Neither gestational age nor the degree of growth restriction was significantly related to the risk of caesarean section or to the risk of moderate or severe neonatal acidosis.
CONCLUSIONS: In cases of severe SGA before 37weeks\' gestation, induction of labour allows vaginal delivery in two-thirds of cases. It is accompanied by a doubling of the risk of moderate or severe neonatal acidosis.
摘要：
目的：如果小于胎龄（SGA）的胎儿由于严重程度（<3百分位）而需要分娩，尝试引产理论上会增加剖腹产和新生儿酸中毒的风险，但是人们对这些风险知之甚少。本文旨在评估在严重SGA的情况下，中度早产胎儿尝试阴道分娩时剖腹产和新生儿酸中毒的风险。
方法：一项以医院为基础的单中心观察性研究，在连续17年的时间里，对头部有单个胎儿的母亲进行了观察性研究，严重的SGA（<3百分位）需要胎儿摘除。如果pH<7.10，则认为新生儿酸中毒是中度的，如果pH<7.0，则认为是重度的。根据出生体重比估计SGA的严重程度。
结果：在此期间，纳入了四十四个患有严重SGA的胎儿，其中140人在诱导后出生(32.3%)。在这个群体中,66.4％的妇女实现了阴道分娩（66.4％CI95[58.0-74.2]），与计划进行剖腹产的胎儿组相比，中度或重度酸中毒的风险增加了一倍（7.9％vs3.1％，OR=2.7[1.1-6.7])。胎龄和生长受限程度均与剖宫产的风险或中度或重度新生儿酸中毒的风险无关。结论：在妊娠37周前重度SGA的情况下，在三分之二的病例中，引产允许阴道分娩。它伴随着中度或重度新生儿酸中毒的风险加倍。
方法：一项以医院为基础的单中心观察性研究，在连续17年的时间里，对头部有单个胎儿的母亲进行了观察性研究，严重的SGA（<3百分位）需要胎儿摘除。如果pH<7.10，则认为新生儿酸中毒是中度的，如果pH<7.0，则认为是重度的。根据出生体重比估计SGA的严重程度。
结果：在此期间，纳入了四十四个患有严重SGA的胎儿，其中140人在诱导后出生(32.3%)。在这个群体中,66.4％的妇女实现了阴道分娩（66.4％CI95[58.0-74.2]），与计划进行剖腹产的胎儿组相比，中度或重度酸中毒的风险增加了一倍（7.9％vs3.1％，OR=2.7[1.1-6.7])。胎龄和生长受限程度均与剖宫产的风险或中度或重度新生儿酸中毒的风险无关。结论：在妊娠37周前重度SGA的情况下，在三分之二的病例中，引产允许阴道分娩。它伴随着中度或重度新生儿酸中毒的风险加倍。
