In Primiparous Women at Term, a Symphysial Fundal Height of 36 cm Is Linked to the Lowest Risk of Emergency Caesarean Section and Postpartum Haemorrhage

BACKGROUND: Guidelines for managing a small symphysial fundal height (SFH) measurement during pregnancy are well established, but guidelines identifying and managing a large SFH measurement at term are not. AIMS: To determine the relationship between a large SFH at term and intra-partum risk, and to determine if there is an SFH cut-off that could predict the following adverse outcomes: emergency caesarean section (CS), instrumental delivery, postpartum haemorrhage (PPH) and admission of neonate to the special care nursery (SCN). MATERIALS AND METHODS: A retrospective audit was performed on 775 deliveries at a regional Australian hospital. SFH measurement at term was the primary variable for investigation. The largest measurement taken within 14 days of delivery was accepted as the primary SFH measurement. RESULTS: In primiparous women, an SFH of 36 cm was associated with the lowest incidence of emergency CS (8%) and 35 cm was associated with the lowest incidence of PPH (8%). Both risks trebled at an SFH of 40 cm (24%) and quintupled at 43 cm (42%). In multiparous women the emergency CS rate was not correlated with SFH, but the PPH rate was correlated. CONCLUSIONS: A SFH measurement at term is currently a neglected but useful measurement for triaging women early in labour. An SFH of 36 cm is most reassuring as the parturient is at low risk of an emergency CS or a PPH whereas a SFH of 40 cm or more indicates increased risk and intra-partum care should be modified to reflect this increased risk.