Ultrasound Evaluation Versus Direct Measurement of Uterine Cavity Length
Ultrasound Evaluation Versus Direct Measurement of Uterine Cavity Length
To determine if uterine cavity length on transabdominal pelvic ultrasound corresponds to
 uterine cavity length at time of IUD insertion. If transabdominal pelvic ultrasound is
 validated as a tool for measuring uterine cavity length, it can be used to guide physicians
 and subsequently patients in IUD insertion planning.
Levonogesterel (progestin only) IUDs have been used in the adult population for decades and
 due to their safety and efficacy are now successfully used in the nulliparous and adolescent
 population for menstrual regulation, dysmenorrhea, and contraception. IUDs have the highest
 continuation rate among teens of all forms of contraception at 12 months (86%). IUDs reduce
 menstrual flow by 90% 12 months post insertion, decrease menstrual cramp severity, and have
 greater than 99% effective contraception. All of this make IUDs an attractive option for our
 teens and their caregivers

 At time of IUD insertion, a uterine sound is used to measure the cavity length. A sound is a
 rigid instrument that is placed inside the uterus to directly measure the uterine cavity
 length and is the standard first step prior to IUD insertion. The cavity length will
 ultimately determine the type and size of IUD that can be placed. Two manufacturers, Mirena ®
 and Sklya ® are currently being used in clinical practice. Mirena requires uterine cavity
 length between 6-10 cm and Sklya requires 4-8 cm length. To determine this length requires a
 pelvic exam and the use of uterine sound, however, approximately 50% of our patient
 population is unable to tolerate pelvic exams due to a variety of factors, such as
 developmental disabilities or pain. Thus, this requires patients to go under general
 anesthesia to have their IUD placed. The goal of this study is to determine if the actual
 uterine cavity length corresponds to the transabdominal measurement of the uterine cavity
 length.

 Uterine size is largely under the influence of estrogen and as an adolescent progresses
 through puberty the dimensions of the uterus change. Given that a large portion of families
 seeking menstrual suppression & regulation present relatively close to menarche (mean age of
 12.3 years old) there is a precedent for an institutional standard for pre-IUD insertion
 transabdominal ultrasound to ensure the uterus is of sufficient caliber

 Prior research has focused on those undergoing intra-operative placement of a Mirena IUD. In
 one retrospective chart review of 56 adolescent patients with developmental disabilities,
 there was a 3.7% (2/56) failure rate of intra-operative IUD placement (abandoned IUD
 insertion in the operating room after anesthesia administration). One failure was due to the
 pelvimetry of the child and the other was due to a uterine cavity length of 4cm which was
 deemed insufficient for the Mirena IUD. In addition, two other patients had a uterus sound to
 less than 6 (5cm and 5.5cm) and Mirena was inserted anyways (Skyla was not available). About
 half of these patients had a pre-operative transabdominal US of the pelvis and the total
 uterine length was measured with an average length of 8.3cm. All uterine cavities were
 measured intra-op with an average length of 7.4cm.

 Ultimately, all prior research has measured the length of the full uterus (uterine fundus,
 body of the uterus, and cervix) which is not representative of the measurement in question
 for IUD placement, the uterine cavity length. We propose a prospective cohort pilot study to
 compare transabdominal ultrasound measurements with uterine sound measurements to determine
 uterine cavity length. If these measures correlate, transabdominal US could be a validated
 pre-insertion tool for the physician and patient to avoid unnecessary anesthetic events and
 have appropriate IUDs available for insertion.
Inclusion Criteria:

 -  Females age 12 - 22 years old at time of transabdominal ultrasound whom are being
 considered for IUD placement as part of routine clinical care will be approached for
 inclusion in the study.

 -  IUD inserted between 12/1/19 and 12/1/20

 -  Received a transabdominal US of the uterus

 Exclusion Criteria:

 -  US never performed

 -  Mullerian anomaly