Key Feature 3a: In a woman with abdominal pain: Always rule out pregnancy if she is of reproductive age.
Skill: Clinical Reasoning
Phase: Hypothesis generation, Investigation
In assessing the 13 year old female who presented to clinic today concerned about abdominal pain, with my trusted pediatric ddx and its generalised inclusion of gynaecological causes in pubertal children, I was indeed prompted to first ask if she has had her first period (she had been having them for "awhile"), and then to obtain some pertinent gynaecological and sexual health history information, including when her last menstrual period was, if she has been sexually active yet, and if she has any symptoms in keeping with a sexually transmitted infection. She denied being sexually active yet, without any symptoms suggestive of an STI (ex: genital discharge or pruritus), and with consistently regular cycles that were free of dysmenorrhea. Because she characterised her pain as mild, along with the fact that she clinically appeared well without signs suggestive of genitourinary pathology, and because I had increased suspicion of nongenitourinary aetiologies for her pain, I trusted her, without any beta hCG backup. This is also taking into consideration the reliability of this patient and her family: that they were concerned enough to bring her to see her family doctor on the same day her self-reportedly minor pain started probably meant I could trust she would return for medical attention if her symptoms were not improving. Going from practically zero to instead a low pretest probability of GU related pathology would prompt me to screen her in my clinic for urine beta hCG, which is an extremely sensitive test for pregnancy (UpToDate, 2017). If I was in a position in which I was ordering bloodwork to investigate the possibility of other diagnoses, I would instead throw in a serum beta hCG (as long as the expected time to get the bloodwork was quick, such as in a hospital or emergency department setting), and I would certainly do this if I had a higher than low pretest probability of possible pregnancy.
A note on sexual history taking in adolescents (and probably applicable to any demographic in general): A sexual history taken with other people present, be it parents, friends, or partners, may be as inconsequential as not taking a sexual history at all. It takes a total of probably 30 seconds to get the parent or whoever else out of the room, and although you may just get the same response, the privacy, along with a statement regarding confidentiality, increases the sensitivity in gathering important pieces of clinical information. Even if you think it is unlikely that a young adolescent has been sexually active yet, if you're a family doctor, you'll likely recognize this as an opportunity to broach the subject of contraception and practicing safe(r) sexual activity.