An interventional study of Ophthalmic Artery Doppler in Ophthalmic Artery, Labor and Delivery and Induction of Labor, sponsored by Fondazione Policlinico Universitario Agostino Gemelli IRCCS. Not yet recruiting. Open to female participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-09-29.
Sponsored by Fondazione Policlinico Universitario Agostino Gemelli IRCCS · Not applicable, Interventional, and Diagnostic
The ophthalmic artery Doppler has been recently proposed as a potential "soft marker" for placental insufficiency in retrospective and observational studies, with similar clinical significance with respect to Uterine Artery (UA) Doppler evaluation and it is currently being investigated as an adjunctive clinical instrument to predict pre-eclampsia (PE) occurrence. Placental insufficiency strictly correlates with intrapartum fetal adverse outcomes and a concomitant induction of labor, alone, may further increase the hypoxic stress on the fetus during labor. This can be reflected by cardiotocographic alterations during labor, ultimately leading to emergency cesarean deliveries or instrumental vaginal deliveries.
Despite great advancements in understanding various maternal-fetal pathologies, the investigators are still not able to properly detect fetuses that are at higher risk for intrapartum compromise among those receiving an induction of labor. Therefore, the aim of this prospective study is to investigate any potential association between altered ophthalmic artery Doppler PSV ratio measured before labor induction in at-term, pregnant patients with intra-partum fetal compromise. Furthermore, the investigators aim to also measure an additional parameter that is the optic nerve sheath diameter (ONSD) - an indirect measure of intracranial pressure - before and after the second stage of labour, with the aim of studying its physiology during and after delivery.
The ophthalmic artery (OA) Doppler has been recently proposed as a potential "soft marker" for placental insufficiency in retrospective and observational studies, with similar clinical significance with respect to Uterine Artery (UA) Doppler evaluation. It has been investigated in small-for-gestational-age (SGA) or fetal-growth-restricted (FGR) fetuses, as well as in low-risk pregnancies and at various gestational ages during pregnancy, showing to be predictive of impaired placentation, and, consequently, of pre-eclampsia occurrence.
The OA is the first branch of the internal carotid artery and its Doppler velocity waveform has two systolic peaks. The first systolic wave (PSV1) is created by cardiac systole, with the opening of the aortic valve and ejection of blood into the aorta, whilst the second systolic wave (PSV2) is a reflective wave formed by the systolic pulse wave reaching smaller, higher resistance arterioles and being reflected back towards the heart. At the level of the aortic arch, a fraction is diverted cranially to the cerebral circulation as a forward wave to create PSV2. In this way, PSV2 is most influenced by peripheral arterial compliance and resistance, whilst PSV1 is more affected by cardiac output. Therefore, an increase in the ratio of PSV2 to PSV1 (PSV ratio) could represent an increase in peripheral vascular resistance and/or a reduction in cardiac output, which are both indirect signs of placental dysfunction. The latter can be manifested during labor with well-established cardiotocographic patterns and induction of labor, alone, may enhance the intrapartum hypoxic stress on the fetus.
Furthermore, another parameter that is currently understudy is the Optic Nerve Sheath Diameter (ONSD). Recent evidence suggests that ONSD increases in pre-eclamptic patients, possibly reflecting a transient increase in intracranial pressure. However, evidence is scarce regarding its physiologic changes during and after labour. In understanding the potential mechanisms behind intrapartum fetal compromise in gravid, at-term patients undergoing labor induction, the hypothesis is that placental dysfunction, albeit not necessarily clinically manifest earlier in pregnancy, may play a role in fetal compromise during labor, especially in pregnancies undergoing induction of labor. Hence, investigating potential associations between a "soft marker" of placental insufficiency as Ophthalmic artery Doppler PSV ratio alterations and intrapartum fetal compromise would be paramount. Therefore the aim of this prospective interventional study is to investigate any association with altered OA PSV ratio and intrapartum fetal adverse outcomes in pregnant patients that reach term of pregnancy, undergoing induction of labor. In addition, the investigatos also aim to evaluate the ONSD before and after the second stage of labour in order to study its physiologic changes.
Exclusion Criteria:
Pregnant patients after 37 weeks of gestation undergoing induction of labor. Before labor induction, participants will undergo maternal ophthalmic artery Doppler assessment and measurement of optic nerve sheath diameter (ONSD). ONSD will be measured again after delivery. Maternal, intrapartum, and neonatal outcomes will be collected.
Diagnostic Test: Ophthalmic Artery Doppler
Right before labour induction, once the patient is already admitted into the inpatient ward - as an elective admission for scheduled labour induction - we will perform an ultrasound by gently applying the probe onto the eyelid of the patient, using sterile gel. We will then measure both the Doppler velocity of the Ophthalmic Artery as well as the Optic Nerve Sheath Diameter (ONSD). The ONSD will then be measured again right after delivery following the exact same procedure.
Also known as: Optic Nerve Sheath Diameter Assessment
Occurrence of in-labor cesarean delivery due to fetal hypoxic stress, assessed in relation to maternal ophthalmic artery Doppler indices measured before induction of labor.
Occurrence of cesarean delivery during labor due to fetal hypoxic stress, evaluated in relation to maternal ophthalmic artery Doppler indices measured before induction of labor.
Time frame: From start of labor induction until delivery, up to 72 hours.
instrumental vaginal delivery for fetal hypoxic stress
Occurrence of instrumental vaginal delivery due to fetal hypoxic stress, evaluated in relation to maternal ophthalmic artery Doppler indices measured before induction of labor.
Time frame: From start of labor induction until delivery, up to 72 hours.
Cesarean delivery for any indication
Occurrence of cesarean delivery for any indication, evaluated in relation to maternal ophthalmic artery Doppler indices measured before induction of labor.
Time frame: From start of labor induction until delivery, up to 72 hours.
Cesarean delivery for clinical or subclinical chorioamnionitis
Occurrence of cesarean delivery due to clinical or subclinical chorioamnionitis, evaluated in relation to maternal ophthalmic artery Doppler indices measured before induction of labor.
Time frame: From start of labor induction until delivery, up to 72 hours.
Umbilical arterial pH <7.0
Occurrence of umbilical arterial cord blood pH \<7.0 at delivery, evaluated in relation to maternal ophthalmic artery Doppler indices measured before induction of labor.
Time frame: At delivery
5-minute Apgar score <7
Occurrence of an Apgar score \<7 at 5 minutes after birth, evaluated in relation to maternal ophthalmic artery Doppler indices measured before induction of labor.
Time frame: 5 minutes after birth
Neonatal Intensive Care Unit admission
Occurrence of neonatal admission to the Neonatal Intensive Care Unit (NICU), evaluated in relation to maternal ophthalmic artery Doppler indices measured before induction of labor.
Time frame: From birth until hospital discharge
Change in Optic Nerve Sheath Diameter (ONSD)
Change in maternal optic nerve sheath diameter measured before labor induction and after delivery.
Time frame: Before labor induction and up to 30 minutes after delivery
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Plan to share: No — There is no plan to make individual participant data (IPD) available.
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Fondazione Policlinico Universitario Agostino Gemelli IRCCS