Unintended pregnancy with IUD in situ reveals the IUD placement into one of the uterine horns in a bicornuate uterus

Description

A 29-year-old gravida 2, para 1, with one living offspring born to a spontaneous vaginal delivery, presented to our outpatient clinic with a positive urine pregnancy test preceded by a missed period. Her history was significant for a copper intrauterine device (IUD) insertion 10 months prior to presentation. Her medical and surgical histories were unremarkable for chronic medical illness, hereditary diseases or major medical and/or surgical events. Transvaginal ultrasound evaluation (figure 1, video 1) revealed a uterus with two distinct uterine horns, each with a separate endometrial cavity as well as muscular tissue, joining into one cervix, consistent with a unicollis bicornuate uterus. A properly placed IUD was visualised in the right horn of the uterus, while the left horn harboured an intrauterine gestational sac containing a viable embryo with demonstrable fetal cardiac activity. The IUD threads were visible, so it was removed; the patient elected to continue the pregnancy and on her last visit for an antenatal check-up, she was at her 25th week of gestation with no adverse maternal or fetal events.

Figure 1.

IUD and embryo in two distinct uterine horns of a bicornuate uterus. IUD, intrauterine device.

Video 1.

Download video file ^{(4.1MB, mp4)}

DOI: 10.1136/bcr-2019-232638.video01

IUD is a very effective method of contraception with cumulative failure rates less than 2% over 10 years of use.¹ Should unintended pregnancy occur in IUD users, it is more likely to be ectopic than intrauterine, so an ectopic gestation must be ruled out as soon as pregnancy is confirmed.² Furthermore, intrauterine pregnancy with an IUD in situ is associated with adverse maternal and fetal pregnancy outcomes, such as chorioamnionitis, preterm labour, placental abruption and increased risk of miscarriage.³ Thus, early removal of IUD should be performed whenever the diagnosis of pregnancy is made if threads are visible or if the IUD is seen in the cervix. If not, then counselling the patients about adverse obstetric outcomes in the setting of continuing pregnancy with an IUD in situ is encouraged. Then, based on the woman’s desire to continue or terminate the pregnancy, gestational age and IUD location, a shared decision about continuing or termination of pregnancy should be taken.¹ Distorted uterine cavity increases the risk of IUD failure, and is considered a relative contraindication to the use of IUD⁴; whenever bicornuate uterus is diagnosed, and long-term reversible contraception is desired, an alternative method to IUD is recommended. Interestingly, insertion of one IUD into each of the uterine horns appears to be an effective alternative.^{5 6}

To the best of our knowledge, this is the sixth well-documented case report of coexistent viable pregnancy and IUD in two distinct horns of a bicornuate uterus. In sharp contrast to the previously reported cases that culminated into either termination of pregnancy or abortion by week 18th of gestation,^7–11 our patient continued to have an uncomplicated pregnancy till the 25th week of gestation, up to her last check-up visit, which may be explained by earlier detection and early management by IUD extraction, thus limiting the adverse effects.

Learning points.

• Ultrasound is an effective modality to assess female genital tract and adnexa for any pathology and it should be performed prior to, as well as, after intrauterine device (IUD) insertion to confirm proper placement.

• Whenever a uterine malformation is suspected by ultrasound prior to IUD insertion, the patient should be referred to a consultant gynaecologist for definite diagnosis of the exact anomaly and subsequent determination of the optimal method of contraception for her.

• Pregnancy with IUD in situ is rare; an ectopic pregnancy must be excluded followed by an attempt at IUD extraction if threads are visible or the IUD is in the cervix.