Measured Versus Hemoglobin-Calculated Postpartum Blood Loss After Waterbirth Compared With Land Birth: A Multicenter Observational Cohort Study
| Registry | NCT07884890 |
|---|---|
| Status | Not yet recruiting |
| Study type | Observational |
| Enrollment | 600 (Estimated) |
| Sponsor | University of Campania Luigi Vanvitelli (Other); collaborators: Azienda Ospedaliera di Rilievo Nazionale e di Alta Specialità San Giuseppe Moscati (Avellino) |
| Conditions | Postpartum Hemorrhage, Waterbirth |
| Interventions | Water immersion during labor and birth (Other) |
| Dates | start 2027-04-01 (estimated), primary completion 2029-04-01 (estimated), completion 2029-10-01 (estimated), first posted 2026-10-21, last updated 2026-10-21 |
| Locations | 2 sites in Italy |
Related Papers Related Patents Related Grants Related Experts
All trials for Postpartum Hemorrhage All trials for Waterbirth All trials of Water immersion during labor and birth
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.
| Arm | Type | Interventions | Description |
|---|---|---|---|
| Group A: Waterbirth | Other: Water immersion during labor and birth | 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. | |
| Group B: Water Immersion in Labor, Birth out of Water | 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. | |
| Group C: Land Birth Without Water Immersion | 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. |
Sex: Female, ages: 18 Years to 50 Years
Inclusion Criteria: * Singleton pregnancy * Cephalic presentation * Gestational age from 37 weeks 0 days to 41 weeks 6 days * Low-risk pregnancy, eligible for water immersion according to the protocol of the center * Hemoglobin measured at admission in labor * Vaginal birth; for Group C, spontaneous vaginal birth with no water immersion at any time in labor Exclusion Criteria: * Blood transfusion before the postpartum blood sample * Known coagulopathy * Cesarean delivery * Operative vaginal delivery (Group C)
| Facility | City | Country | Status |
|---|---|---|---|
| Azienda Ospedaliera San Giuseppe Moscati - UOC di Ginecologia e Ostetricia | Avellino, Campania | Italy | |
| University of Campania Luigi Vanvitelli | Caserta, Campania | Italy |