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.