Imperforate hymen, a rare congenital anomaly of the female genitourinary tract, is defined as the hymen completely obstructing the vaginal opening. Typically, the diagnosis is made at either birth or menarche. Here, we present an unusual case of imperforate hymen in a 4 month of child causing massive hydrocolpos and severe bilateral hydroureteronephrosis.

A retrospective chart review of notes, radiographic studies, and intraoperative photos was performed.

A 4 month old female presented to the emergency department with worsening abdominal distension and decreased urine output.
Abdominal ultrasound showed a bilateral hydroureteronephrosis and a large cystic pelvic mass. The emergency department then ordered a CT abdomen/pelvis, which showed a large fluid filled collection posterior to the bladder consistent with massive hydrocolpos (Figure 1). Her past medical history was significant for a home midwife delivery and no prior examination by a pediatrician. Her family reported normal antenatal ultrasounds, although it was unclear when the final ultrasound was performed. She was on no medications, however, her parents did apply topical essential oils. Initial general surgery recommendations were for MRI. Pediatric urology noted a bulging, blue imperforate hymen on physical examination (Figure 2) and took her urgently to the operating room for hymen incision and reconstruction. Incision of the hymen immediate returned 400 mL of thick milky fluid. The incision was converted into a true cruciate pattern. The vaginal epithelium and vaginal mucosa were re-approximated with 5-0 Vicryl (Figure 3). A Foley catheter and Penrose drain were placed after copious vaginal irrigation. The drain and catheter were removed post-operative day one. She was discharged home post-operative day two. At two month follow up, her hydronephrosis had resolved and she was thriving.

The etiology of imperforate hymen is thought to be due to failure of re-canalization where the uterovaginal canal meets the urogenital sinus.  After delivery and maternal estrogen subsides, the hymen opening expands to its normal crescent shape. The diagnosis is typically made with: prenatal ultrasound, newborn physical exam, or later at menarche ( with cases of microperforate hymen)[1].
The treatment options include cruciate hymenectomy (gold standard) versus hymen sparing surgery [2]. Some suggest that essential oil ingredients may be endocrine disrupters, possibly explaining her profound mucous production causing massive hydrocolpos [3].

A careful newborn examination is crucial to identify congenital anomalies that may have significant sequelae. Several diagnoses that cause hydrocolpos and hydronephrosis can be identified on physical examination, occasionally negating the need for extensive radiographic evaluation.

Abdelrahman HM, Jenkins SM, Feloney MP. Imperforate Hymen. [Updated 2023 Nov 12]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan.
Acar A, Balci O, Karatayli R, Capar M, Colakoglu MC. The treatment of 65 women with imperforate hymen by a central incision and application of Foley catheter. BJOG. 2007 Nov;114(11):1376-9.
Hawkins J, Hires C, Dunne E, Baker C. The relationship between lavender and tea tree essential oils and pediatric endocrine disorders: A systematic review of the literature. Complementary therapies in medicine. 2020 Mar; 49: Article102288.