2 Mother and baby did well following delivery. While the mother had no complaints in the postpartum period, she was noted to have several new small petechiae on her face and blood in her left ear about one hour after delivery. The right ear appeared grossly normal and the patient denied placing anything in the ear. However, otoscopic examination of the left external auditory canal revealed minimal dark blood and 1 cm superﬁcial thrombus blocked a clear view of the eardrum. No active bleeding was observed and the patient remained afebrile. The patient reported no ear pain and denied any reduction in hearing sensitivity from either ear. Gentle extraction resulted in removal of the clot, revealing a 2-3 mm perforation in the inferior aspect of the left tympanic membrane. Otic lavage with bulb-syringe was not performed. Consultation with an ophthalmologist conﬁrmed left tympanic membrane perforation. The con- tralateral tympanic membrane was intact. Cotton packing was placed in the ear canal and the left tympanic membrane was allowed to heal; antibiotics were not prescribed. At the postpartum follow-up exam six weeks later, the patient had no complaint and no additional ear bleeding was reported. She had no ear pain or hearing deﬁcit, and the left eardrum appeared grossly normal. The patient was counseled to treat future ear infections promptly, to seek treatment immediately should any ear discharge be noted, and to avoid insertion of any object into the ear to clean it. 3. Discussion The second stage of labor begins with full dilation. Expulsion of the fetus is accompanied by several physiologic events associated with remarkable changes in intra-abdominal pres- sure. The “forces by which the child is expelled” classically include voluntary (straining or bearing down) and involun- tary (uterine contraction) components [1]. During vaginal delivery, the laboring woman is often encouraged to inhale deeply, close her glottis, and contract her abdominal muscles to generate greatly increased intra-abdominal pressure [2]. The transient but repeated pressure elevations can also aﬀect other organs including the eye [3] and lung [4]. A substantial rise in middle ear pressure also occurs, and may result in tissue damage if not equilibrated gradually [5]. In humans, the tympanic membrane can withstand only limited pressure diﬀerentials and may rupture when this pressure exceeds 35 kPa (5 psi) [6]. While this pressure threshold is diﬀerent for individual patients, at 100 kPa (14 psi) almost all eardrums will be ruptured [7]. The most common cause of ear barotrauma is high-altitude air travel [8] but modern pressurized cabins have virtually eliminated this risk. The eﬀect is also operant during rapid ascent while scuba diving [9] and if transcanal pressure is not equalized, perforation of the tympanic membrane may occur [10]. In our case, the patient appears to have generated a pressure gradient during closed-glottis pushing similar to that registered during quick ascent in an unpressurized aircraft cabin or while scuba diving, but intra-abdominal pressure was not directly measured during delivery for Case Reports in Medicine our patient. Previous work has reported the average intra- abdominal pressure associated with “bearing down eﬀorts” of second-stage labor to be about 25 kPa [11]. Given the largely unavoidable urge to valsalva vigorously and the severe spike in middle ear pressure associated with labor, it is somewhat surprising that tympanic membrane rupture is not encountered more often during delivery. However, pregnant patients can be counseled about spon- taneous pushing techniques (open glottis pushing while breathing out) in the second stage of labor. This approach has been associated with subjectively “more eﬀective pushing”, shorter second stage labor and improved neonatal outcome [12]. While an eardrum perforated during labor may be uncomfortable, it typically heals on its own. Any hearing loss that accompanies tympanic membrane perforation is usually transient, although patients should seek reevaluation if ear symptoms persist or worsen. 4. Conclusion While the incidence of intrapartum eardrum perforation is unknown, our report is only the second published description of this event [13] and is the ﬁrst such case to appear in the English medical literature. As this case illustrates, comanagement with an otolaryngologist is helpful for any pregnant or post-partum patient with blood observed in the ear canal, or whenever subjective change in hearing is noted. Notwithstanding the standardized role of the valsalva maneuver during second-stage labor [12], alternate pushing strategies should be considered whenever possible. While instrumental vaginal delivery (i.e., vacuum, forceps) reduces maternal eﬀort during the second stage of labor, the risk of such intervention must be evaluated against the incidence of intrapartum tympanic membrane rupture, which is likely to be quite low. Acknowledgment The authors are grateful to Dobromina Kalinova for provid- ing the Bulgarian translation. References [1] A. F. A. King, King’s Manual of Obstetrics, Lea Brothers & Co., Philadelphia, Pa, USA, 10th edition, 1907. [2] F. G. Cunningham, et al., Williams Obstetrics, McGraw-Hill, New York, NY, USA, 21st edition, 2001. [3] A. Ladjimi, S. Zaouali, R. Messaoud, et al., “Valsalva retinopa- thy induced by labour,” European Journal of Ophthalmology, vol. 12, no. 4, pp. 336–338, 2002. [4] M. Miguil and A. Chekairi, “Pneumomediastinum and pneu- mothorax associated with labour,” International Journal of Obstetric Anesthesia, vol. 13, no. 2, pp. 117–119, 2004. [5] D. Graver, PADI Dive Manual, Professional Association of Diving Instructors, Santa Ana, Calif, USA, 1978. [6] A. Leonard, D. Forcino, and R. Walker, Medical Consequences of Nuclear Warfare, Oﬃce of the Surgeon General, Department of the Army, USGPO, Falls Church, Va, USA, 1989. [7] C. Stewart, “Blast injuries: preparing for the inevitable,” Emergency Medicine Practice, vol. 8, pp. 1–28, 2006.