The goal of this study is to obtain user feedback while placing and observing the DAISY uterine drain with wall suction. This study defines the obstetrical surgeons as "users" and the patients in whom the drain is placed as "participants." Participants are pregnant women who are undergoing cesarean delivery (CD), who have not entered active labor, who have consented to drain placement and who have met all the inclusion/exclusion criteria. Users are staff or fellow obstetrical surgeons who will use the drain and provide the evaluation.

Postpartum hemorrhage (PPH) is the leading cause of maternal mortality worldwide. (D'Alton 2020). It is estimated that 14 million cases of PPH occur each year worldwide (Rath, 2011). In the United States, PPH causes up to 12% of maternal deaths and is the leading cause of death occurring on the day of delivery (ACOG 2017; Butwick 2019; Evensen 2020; Hawkins 2020). According to the American College of Obstetricians and Gynecologists (ACOG), between 54% and 93% of PPH-associated mortality may be preventable while 70-80% of PPH is due to abnormal uterine tone (atony) (ACOG 2017). Atony involves a deficient response to physiological signals that promote uterine contraction and blood vessel compression after delivery. Contraction of the myometrium compresses the blood vessels supplying the placental bed and thereby causes mechanical hemostasis. Uterine atony following CD is a relatively common problem in the non-laboring patient because contraction of the myometrium is almost entirely absent. Restoring uterine tone can be addressed through 1) medication, 2) surgery, or 3) mechanical means. Post-partum unrecognized uterine hemorrhage due to a closed or narrow cervix that allows blood to collect in a patient undergoing a CD could lead to complications such as dangerously low blood pressure. The DAISY drain is intended to provide a channel through the cervix for fluid drainage after pelvic surgery. The DAISY device consists of a soft silicone drainage tube (proximal end) attached to a semi-flexible catheter, inserted through the hysterotomy created at the time of the CD. The DAISY drain is placed intraoperatively after delivery of the placenta, stabilization of the patient, and cleansing of the uterine cavity but prior to closure of the hysterotomy. The drain is placed through the hysterotomy and threaded through the cervix and vaginal canal, out the introitus, so the distal end is accessible outside of the body. In this study, the drain is placed on continuous suction according to the IFU for the first two postoperative hours or more if required. At the end of the 2-hour period, the uterus is evaluated by manual palpation and abdominal ultrasound. The abdominal ultrasound is performed to document device placement and to assess uterine involution, approximate uterine size and uterine cavity size, presence of intrauterine clots or retained products of conception. The trained user removes the drain after at least two hours post-surgery based on clinical management. Suction is discontinued before removal. One method of determining if the drain is no longer needed is by checking and documenting uterine tone. If uterine tone has returned to normal as assessed by palpation, the DAISY drain may be removed.

Inclusion Criteria:

• The participants consist of women undergoing planned CD for reasons unrelated to this study.

Exclusion Criteria:

• Known intrauterine or cervical pathology that would interfere with device placement and/or use
• Ongoing intrauterine pregnancy
• Untreated uterine rupture
• Unresolved uterine inversion
• Current cervical cancer
• Current purulent infection of vagina, cervix, or uterus
• Retained products of conception
• Arterial bleeding requiring surgical or angiographic embolization
• Indication for hysterectomy
• Lack of study consent or unable to provide informed consent,
• Any condition (temporary or permanent) in which the investigator or user deems the patient unsuitable for the study procedures

Only adult women over the age of eighteen can be included.

Adult women who were having a scheduled CD for reasons that were unrelated to the study.

Adverse events were collected for 1 day (day of surgery).

Small sample size, single-site setting, reliance on historical controls; perioperative fluid shifts may confound hemoglobin-based blood-loss estimates.