Predicting perinatal outcome through changes in umbilical artery Doppler studies after antenatal corticosteroids in the growth-restricted fetus.

OBJECTIVE: To investigate whether persistently absent umbilical artery end-diastolic flow in the intrauterine growth-restricted fetus after betamethasone administration is associated with altered perinatal outcomes. METHODS: This is a retrospective cohort study of 92 pregnancies complicated by intrauterine growth restriction (IUGR) and absent end-diastolic flow in which antenatal betamethasone was given. Predefined maternal outcomes (maternal age, gestational age at diagnosis of absent end-diastolic flow, gestational age at delivery, preexisting medical conditions) and neonatal outcomes (including birth weight; perinatal mortality; duration of neonatal intensive care unit admission; requirement for intubation, assisted ventilation, inotropic support; duration of supplemental oxygen, assisted ventilation; respiratory distress syndrome, necrotizing enterocolitis, intraventricular hemorrhage) were analyzed. RESULTS: Betamethasone administration was associated with a transient return of end-diastolic umbilical artery flow in 58 pregnancies (63%) and persistent absent end-diastolic flow in 34 (37%). Persistent absent end-diastolic flow was seen more frequently in women with prepregnancy medical disorders (59% compared with 24%, P<.001). Neonates from the persistent absent end-diastolic flow subgroup were more likely to require assisted ventilation (93.1% compared with 73.5%, P=.03) and to have longer durations of assisted ventilation (median time 30 days compared with 4 days, P=.03) and supplemental oxygen (median time 45 days compared with 4 days, P=.04). CONCLUSION: Betamethasone administration is associated with a transient return of end-diastolic flow in two thirds of pregnancies complicated by IUGR and umbilical artery absent end-diastolic flow. Persistent absent end-diastolic flow in the umbilical artery after betamethasone administration may identify a subgroup of fetuses with IUGR at further heightened perinatal risk that, as neonates, are more likely to require assisted ventilation and a longer duration of ventilation and supplemental oxygen.

Maternal serum activin A and the prediction of intrauterine growth restriction.

BACKGROUND: Differentiating between the small healthy fetus and the high risk growth restricted fetus remains a significant obstetric challenge. It has been previously shown that maternal activin A levels are increased in association with fetal growth restriction. AIM: To evaluate maternal serum activin A as a marker of fetal growth restriction. METHODS: Prospective cohort study of 62 women referred for fetal assessment because of a clinical suspicion of a small for gestation fetus. Maternal serum levels of activin A were measured with an ELISA. RESULTS: Activin A levels, expressed as median (95% CI) MoMs, were similar in the women with a normal-sized fetus and in those with a healthy small for gestational age fetus, 1.14 (95% CI 1.0-1.5) and 1.31 (95% CI 0.8-2.1), respectively (P = 0.97). Compared to the women with a normal-sized fetus or a healthy small fetus, activin A levels were significantly elevated in the women who had an intrauterine fetal growth restriction fetus 2.37 (95% CI 1.6-3.7; P = 0.01 compared to normal and P = 0.04 compared to healthy small). CONCLUSIONS: These data confirm that circulating activin A is increased in association with fetal growth restriction. However, a single blood sample for activin A will not efficiently discern between healthy and compromised small fetuses.

Changes in umbilical artery flow velocity waveforms following maternal administration of betamethasone.

In a retrospective cohort study we have previously shown that administration of betamethasone to women with a pregnancy complicated by absent end-diastolic flow in the umbilical artery (UA) is associated with altered UA flow velocity waveforms. To examine this phenomenon further we undertook a prospective study of 30 similar singleton pregnancies. Umbilical artery FVWs were recorded before and after betamethasone administration using real-time pulsed wave colour flow Doppler. The results of this prospective cohort were similar to those of the retrospective study allowing pooling of the data. Of the 55 total pregnancies with umbilical artery AEDF studied betamethasone administration was associated with the return of end-diastolic flow in 39 (71 per cent; 95 per centCI: 59-83 per cent). The median (range) duration of this change was 3 (1-10) days. There is no evidence that this change has either a beneficial or detrimental effect on foetal health. Administration of betamethasone to women with a pregnancy complicated by umbilical artery AEDF is associated with the transient return of end-diastolic flow in most cases. While the mechanisms underlying this effect are yet to be fully elucidated it has implications for foetal surveillance in these high-risk pregnancies.

Betamethasone associated changes in umbilical artery flow velocity waveforms in multiple pregnancies with umbilical artery absent end diastolic flow.

OBJECTIVES: It has been previously shown that glucocorticoids alter umbilical artery flow velocity waveforms in singleton pregnancies complicated by umbilical artery absent end diastolic flow. Whether similar effects are evident in multiple pregnancies where one fetus has umbilical artery absent end diastolic flow is not known. METHODS: Women with a twin or triplet pregnancy complicated by umbilical artery absent end diastolic flow in one fetus were admitted to hospital for intensive fetal surveillance including daily umbilical artery flow velocity waveform studies, as per hospital protocol. All women received prophylactic betamethasone (11.4 mg x 2, 24 h apart) in anticipation of preterm delivery. RESULTS: Between October 1996 and February 2002, 24 women with a multiple pregnancy complicated by umbilical artery absent end diastolic flow were cared for. Of these, six had a pregnancy with feto-fetal transfusion and excluded from further analysis. Of the remaining 18 women, eight had monochorionic diamniotic twins, eight had dichorionic twins, and two had trichorionic, triamniotic triplets. The median (range) gestation at diagnosis of umbilical artery absent end diastolic flow was 210.5 days (173-241). In nine (50%) of the 18 pregnancies the administration of betamethasone was associated with return of umbilical artery end diastolic flow for a median of 5 days. There was no association between this effect and chorionicity. The median (range) interval from diagnosis of umbilical artery absent end diastolic flow to delivery was 11 days (1-46). CONCLUSIONS: As previously reported in singleton pregnancies, the maternal administration of betamethasone in multiple pregnancies with umbilical artery absent end diastolic flow is associated with a transient return of end diastolic flow.