Abstract:
Objective: Compare the risk of recurrent adverse delivery
outcome (ADO) or adverse neonatal outcome (ANO) between consecutive
gestational diabetes (GDM) pregnancies.
Design: Retrospective cohort
Setting: Sydney, Australia
Population or Sample: 424 pairs of consecutive singleton GDM
pregnancies, 2003-2015
Main Outcome Measures: . ADO: instrumental delivery and
emergency Caesarean. ANO: large for gestational age (LGA), small for
gestational age (SGA), and composite ANO (LGA/SGA/stillbirth/neonatal
death/shoulder dystocia).
Methods: Using each pregnancy pair (“index” and
“subsequent” pregnancy), we calculated ADO and ANO rates and
determined risk factors for subsequent pregnancy outcomes (multivariate
regression).
Results: Subsequent pregnancies had higher rates of elective
Caesarean (30.4% vs 17.0%, p<0.001) and lower rates of
instrumental delivery (5% vs 13.9%, p<0.001), emergency
Caesarean (7.1% vs 16.3%, p<0.001) and vaginal delivery
(62.3% vs 66.3%, p=0.01). ANO rates in index and subsequent
pregnancies did not differ. Index pregnancy adverse outcome was
associated with a higher risk of repeat outcome: RR 3.09 (95%CI:1.30,
7.34) for instrumental delivery, RR 2.20 (95%CI:1.06, 4.61) for
emergency Caesarean, RR 4.55 (95%CI:3.03, 6.82) for LGA, RR 5.01
(95%CI:2.73, 9.22) for SGA and RR 2.10 (95%CI:1.53, 2.87) for
composite ANO). The greatest risk factor for subsequent LGA (RR 3.13
(95%CI:2.20, 4.47)), SGA (RR 4.71 (95%CI:2.66, 8.36)) or composite ANO
(RR 2.01 (95%CI:1.46, 2.78)) was having the same outcome in the index
pregnancy.
Conclusions: Women with GDM and an adverse outcome are at very
high risk of the same complication in their subsequent GDM pregnancy,
representing a high-risk group that should be targeted for directed
management over routine care.
Funding: nil
Key Words: diabetes in pregnancy