Timing of delivery in antenatal fetal hydronephrosis: a snap shot social media survery of obstetric and fetal medicine practice

Objectives: To identify when obstetricians would deliver a fetus with antenatal hydronephrosis and normal liquor. Designed as snap-shot survey. Setting: Survey Monkey link. Population/sample were obstetrics and fetal medicine consultants who received the survey link via closed professional forums on the North West Coast Maternity Clinical Network, Facebook, and publicly on Twitter. Methods: Survey link publicised as above, obstetric consultants were asked at what gestation would they deliver a fetus with antenatal hydronephrosis and normal liquor; and what criteria would they use to make that decision. Main outcome measures were number of years in practice, gestation at delivery, anteroposterior diameter (APD) of renal pelvis. Results: A total of 44/102 respondents (43%) would deliver prior to 40 weeks (median no. of years as consultant 10 years [IQR 5-17]) vs. those who would not (median years as consultant 5.5 [IQR 3-12]). Re APD threshold of delivery: 17 indicated delivery if the APD were 20 mm, 10 if it were 21-30 mm and 16 if it were >30 mm. Re gestation at which they would deliver: 13 indicated 37-38 weeks, 13 indicated 38-39 weeks and 17 indicated 39-40 weeks. Reasons selected for delivery before term were obstetric anxiety n=2, maternal request n=2, maternal anxiety n=2 and concern about fatal renal damage/renal damage n=34. Conclusions: A surprising number of respondents would consider early delivery of a fetus with hydronephrosis and normal liquor despite the lack of evidence of benefit. The evidence supporting term delivery means that early term delivery is only indicated for obstetric reasons in this scenario.