Gupta AS

Pelvic masses detected late in pregnancy or in labor create diagnostic as well as management conflicts. These masses can be from gynecologic or non gynecologic organs. Uterine masses like leiomyomas, ovarian lesions like functional or neoplastic cysts (benign or malignant), paraovarian cysts or hydrosalpinx originate from the female reproductive organs whereas tumors form the bowel, bladder, ureters, muscles, bony pelvis are non gynecologic masses. Large fecoliths or bladder calculi can also masquerade as a pelvic mass. 
Large pelvic masses irrespective of the organ of origin if they lie below the presenting part in late pregnancy or at start of labor will prevent the descent of the presenting part and will lead to obstructed labor if undetected or neglected.
The occurrence of obstructed labor due to pelvic masses in recent times has reduced due to early detection and follow up or treatment in pregnancy with widespread practice of women registering early in pregnancy, having pelvic examinations and undergoing if not multiple then at least one ultrasonography in pregnancy. Presently, asymptomatic pelvic masses are detected due to almost ubiquitous use of ultrasonography and due to the increased sensitivity available with ultrasound technology. Previously, in the pre ultrasound period, many of these masses were detected either after symptoms developed or else during cesarean section or in the puerperium.
Most of the adnexal masses are ovarian cysts usually benign and functional. Simple cysts less than 5 cm in size usually resolve spontaneously in the second trimester of pregnancy and need only ultrasonography follow up. Complex ovarain cysts or even simple cysts larger than 5 cm in size do resolve spontaneously in about 70% of the women. If these cysts do not resolve spontaneously then surgical treatment may have to be considered. The first half of the pregnancy or upto 22 to 24 weeks of gestation is the best time recommended for surgery in the pregnant woman. Early surgery may be unnecessary as most of these lesions resolve. Delay in elective surgical treatment may result in an emergency procedure for indications like torsion. Approximately 5% of the adnexal masses are malignant. Doppler studies may be able to indicate its malignant nature. 
Once diagnosed, these masses need close followup to chart the most optimal treatment plan. In many cases surgery may be deferred for unresolved pelvic masses till cesarean section (not done for the pelvic mass) or till puerperium. Sometimes these masses increase in size like fibroids. Solid tumors like subserosal, pedunculated fibroids, or fibroids situated in the lower segment, and ovarian cysts may fill the pelvis and prevent engagement of the presenting part. Similarly large vesical calculi or impacted fecoliths in the rectum and the sigmoid colon reduce the pelvic diameters and either prevent engagement of the presenting part or cause obstructed labor. 
Though the number of women seeking antenatal care is increasing there is still a significant number of gravid women who present in labor or are delivered by untrained birth attendants. In early labor and with a detailed clinical examination and availability of ultrasound a provisional diagnosis is usually reached and appropriate treatment can be carried out without increased maternal and perinatal morbidity. However, when such a gravida presents in advanced labor showing all signs of obstructed labor; diagnosis becomes difficult but not impossible as many times the clinical findings are distorted. Ultrasonography, magnetic resonance imaging if available may provide the diagnosis. Delay in treatment can increase the maternal and perinatal morbidity and mortality. Chances of uterine rupture, ischemic necrosis of the bladder leading to fistula formation are real risks. Obstetrician has to anticipate difficulties during cesarean delivery due to the distorted anatomy and be careful to avoid hollow viscus injury.
This November issue of JPGO brings a couple of rare cases. One of these is a large vesical calculus diagnosed for the first time in labor. I hope our esteemed readers enjoy the collection of cases in this issue.