An observational study in Postpartum Hemorrhage and Waterbirth, sponsored by University of Campania Luigi Vanvitelli. Not yet recruiting at 2 sites in Italy. Open to female participants aged 18 Years to 50 Years. Per ClinicalTrials.gov, last updated 2026-10-21.
Sponsored by University of Campania Luigi Vanvitelli · Observational
During a waterbirth, blood lost in the pool between the birth of the baby and the mother's exit from the water cannot be collected or measured. At the participating centers, blood loss is measured with a graduated collector bag that is positioned only after the woman leaves the pool, for the delivery of the placenta. The blood loss recorded after a waterbirth may therefore be lower than the true loss. The goal of this observational study, conducted in two Italian hospitals, is to learn whether measured blood loss underestimates true blood loss more after waterbirth than after birth on land. The main question it aims to answer is: Is the difference between blood loss calculated from the drop in hemoglobin and blood loss measured in the collector bag larger in women who give birth in water than in women who give birth on land without water immersion? Researchers will compare three groups of low-risk women with a singleton pregnancy at term: women who give birth in water, women who use water immersion during labor but give birth out of water, and women who do not use water immersion. No intervention is assigned by the study: each woman is classified according to what actually happened during her labor and birth. Data are taken from the clinical record and include hemoglobin at admission in labor and after birth, measured blood loss, and the timing of events in the pool and during the third stage of labor.
Design: multicenter observational cohort study conducted in two centers in Italy (Caserta and Avellino), with consecutive inclusion over 24 months. Exposure groups are defined by what actually occurred: Group A, birth in water; Group B, water immersion during labor with birth out of water (the reason for leaving the pool is recorded); Group C, no water immersion and spontaneous vaginal birth on land. All consecutive Group A and Group B births in the study period are included. Group C is formed from the delivery ward register of the same center: for each waterbirth (index case), the next three consecutive eligible births of the same parity category (nulliparous or parous) occurring within 30 days are selected; each woman can serve as a control only once, and every woman screened and skipped is logged with the reason. Eligibility of controls is decided on admission data, without knowledge of outcomes. A control with missing data is not replaced. Epidural analgesia is not an exclusion criterion; it is recorded and the analysis is repeated without those women. Blood loss assessment: measured blood loss is the volume collected in a graduated collector bag. After waterbirth the bag is positioned after the woman leaves the pool, for the delivery of the placenta. Calculated blood loss = estimated blood volume x (pre-delivery hemoglobin - postpartum hemoglobin) / pre-delivery hemoglobin, where estimated blood volume (mL) = maternal weight (kg) x 85. Pre-delivery hemoglobin is measured at admission in labor; postpartum hemoglobin is targeted at 48 hours after birth (accepted window 36 to 60 hours), at the same interval in all groups. Primary analysis: comparison between Group A and Group C of the individual difference between calculated and measured blood loss, adjusted for center, maternal age, parity, body mass index, gestational age, onset of labor, oxytocin use, duration of the first and second stage, birth weight, intravenous fluids between the two blood samples, iron therapy in pregnancy, and hours between birth and the postpartum sample. Mechanism analysis: in Group A, the difference between calculated and measured blood loss is modeled as a function of the minutes between birth and positioning of the collector bag; minutes spent in the pool after birth are used in a sensitivity analysis. A further sensitivity analysis is restricted to women sampled between 36 and 60 hours after birth. Sample size: anticipated total enrollment of 600 women over 24 months across the two centers, with three Group C controls for each Group A waterbirth; all eligible women in Group B are included. The standard deviation of the primary outcome will be re-estimated on the first 100 cases, pooled across groups and without examining the between-group difference, and the sample size updated accordingly. Prespecified secondary analyses on the same cohort: duration and management of the third stage of labor after waterbirth versus land birth; influence of postpartum sampling time and intravenous fluids on calculated blood loss; association between duration of water immersion and postpartum hemoglobin drop; reasons for leaving the pool before birth and related outcomes; perineal trauma by parity. Neonatal and infectious outcomes are reported descriptively only, because the study is not powered for rare events.
456 studies on the registry are indexed under Postpartum Hemorrhage; 77 are open to participants now.
This study's planned enrollment of 600 is above the median of 169 across 94 observational studies indexed under Postpartum Hemorrhage.
Browse Postpartum Hemorrhage studies →University of Campania Luigi Vanvitelli is the lead sponsor of 174 studies on the registry; 28 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Low-risk women with a singleton pregnancy at term giving birth at two Italian maternity units (Caserta and Avellino) that offer water immersion in labor and waterbirth. Women are identified consecutively from the delivery ward register and classified according to their actual use of water immersion.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Women who gave birth in water. All consecutive waterbirths in the study period are included. The graduated collector bag is positioned after the woman leaves the pool, for the delivery of the placenta. No intervention is assigned by the study.
Other: Water immersion during labor and birth
Women who used water immersion during labor and gave birth out of water. All consecutive women in the study period are included, and the reason for leaving the pool is recorded. No intervention is assigned by the study.
Other: Water immersion during labor and birth
Women with no water immersion at any time in labor and a spontaneous vaginal birth on land. For each waterbirth, the next three consecutive eligible births of the same parity category within 30 days are selected from the delivery ward register. No intervention is assigned by the study.
Exposure of interest, not assigned by the study. Women choose whether to use the birthing pool as part of routine care: immersion in warm water during labor only (Group B) or during labor and birth of the baby (Group A). The study only observes and records the exposure and its timing.
Difference between calculated and measured blood loss
Individual difference, in mL, between calculated blood loss and blood loss measured in the graduated collector bag. Calculated blood loss = maternal weight (kg) x 85 x (hemoglobin at admission in labor - postpartum hemoglobin) / hemoglobin at admission in labor. The difference is compared between Group A (waterbirth) and Group C (land birth without water immersion).
Time frame: From admission in labor to the postpartum hemoglobin measurement (target 48 hours after birth, accepted window 36 to 60 hours)
Peripartum hemoglobin drop
Hemoglobin at admission in labor minus postpartum hemoglobin, in g/dL, compared between groups. The proportion of women with a drop of 2 g/dL or more is also reported.
Time frame: From admission in labor to the postpartum hemoglobin measurement (target 48 hours after birth, accepted window 36 to 60 hours)
Postpartum hemorrhage of 500 mL or more, by each assessment method
Proportion of women with blood loss of 500 mL or more, reported separately for blood loss measured in the collector bag and for calculated blood loss, and compared between groups.
Time frame: From birth to the postpartum hemoglobin measurement (target 48 hours after birth, accepted window 36 to 60 hours)
Postpartum hemorrhage of 1000 mL or more, by each assessment method
Proportion of women with blood loss of 1000 mL or more, reported separately for blood loss measured in the collector bag and for calculated blood loss, and compared between groups.
Time frame: From birth to the postpartum hemoglobin measurement (target 48 hours after birth, accepted window 36 to 60 hours)
Red blood cell transfusion
Proportion of women receiving a red blood cell transfusion after birth, and number of units transfused, compared between groups.
Time frame: From birth to hospital discharge, an average of 3 days
Intravenous iron administration
Proportion of women receiving intravenous iron after birth, compared between groups.
Time frame: From birth to hospital discharge, an average of 3 days
Duration of the third stage of labor
Minutes between birth of the baby and delivery of the placenta, compared between Group A and Group C.
Time frame: From birth of the baby to delivery of the placenta, up to 2 hours
Plan to share: No — Individual participant data will not be shared due to institutional policies and the protection of participants' privacy.
No publications or documents are linked to this record.
Start is estimated for Apr 2027; primary completion for Apr 2029, 24 months later.
Of 38 non-industry observational studies under Postpartum Hemorrhage, half reached primary completion within 30 months of starting (the median), counting those still running; a quarter within 9 and three quarters within 39. This study's planned 24 months is below that.
Counting every sponsor, half of 42 studies reached it within 20 months; a quarter within 9 and three quarters within 38.
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
This study is not yet recruiting, as verified in Oct 2026. You cannot join it, but the record below documents what was studied.
Get an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
University of Campania Luigi Vanvitelli →