ARRHYTHMIA; CHEST PAIN; SHORTNESS OF BREATH; MATERNAL EXPOSURE DURING PREGNANCY; This solicited pregnancy report received from a consumer concerned a 29 year old female of unknown race and ethnic origin. The patient was enrolled in a non-company sponsored study. The patient's weight was 72.56 kilograms, and height was not reported.  The patient's past medical history included: e-cigarette smoker, recreational drug use, and ectopic or tubal pregnancy, and concurrent conditions included: attention deficit hyperactivity disorder, non alcohol user, and non tobacco user. The patient initiated treatment with covid-19 vaccine ad26.cov2.s (suspension for injection, route of admin not reported, batch number: 041A21A, and expiry: UNKNOWN) dose was not reported, 1 total administered at gestational age 3 weeks and 5 days on 08-APR-2021 for covid-19 immunisation. Concomitant medications included amfetamine aspartate/amfetamine sulfate/dexamfetamine saccharate/dexamfetamine sulfate, ascorbic acid/betacarotene/calcium sulfate/colecalciferol/cyanocobalamin/ferrous fumarate/folic acid/nicotinamide/pyridoxine hydrochloride/retinol acetate/riboflavin/thiamine mononitrate/tocopheryl acetate/zinc oxide, cetirizine hydrochloride, chlorphenamine maleate/dextromethorphan hydrobromide/paracetamol/phenylephrine hydrochloride, docosahexaenoic acid, fluticasone propionate, and oxymetazoline hydrochloride.  On 08-APR-2021, the patient experienced maternal exposure during pregnancy. The date of the patient's last menstrual period was 13-MAR-2021 and expected delivery date was 18-DEC-2021.The patient reported that was singleton pregnancy. On 24-AUG-2021, the patient experienced arrhythmia, chest pain and shortness of breath. On 24-AUG-2021 and 25-AUG-2021 the patient went to emergency room (ER) and tested with Electrocardiogram (ECG) came back normal. On AUG-2021,heart monitoring in ER revealed no abnormalities. The pregnancy was continuing. The action taken with covid-19 vaccine ad26.cov2.s was not applicable. The patient had not recovered from arrhythmia, chest pain, shortness of breath and maternal exposure during pregnancy. The reporter considered the causality between covid-19 vaccine ad26.cov2.s, and arrhythmia as related. The reporter did not provide a causality assessment between covid-19 vaccine ad26.cov2.s, and maternal exposure during pregnancy, chest pain, and shortness of breath. Company causality between covid-19 vaccine ad26.cov2.s, and maternal exposure during pregnancy was not related, and between covid-19 vaccine ad26.cov2.s, and chest pain, arrhythmia and shortness of breath was related.  This report was serious (Other Medically Important Condition).  This case was reassessed as serious based on additional information received from consumer on 06-SEP-2021. The following information was updated and incorporated into the case narrative: Disease(Non alcohol user, non tobacco user),Pregnancy(LMP, gestation period, expected delivery date), lab data (Electrocardiogram, heart monitoring), Events(Arrythmia, chest pain and shortness of breath),labelling and causality were updated, narrative regenerated.; Sender's Comments: V1: 20210801145-covid-19 vaccine ad26.cov2.s-arrhythmia, chest pain, shortness of breath . This event(s) is considered related. The event(s) has a compatible/suggestive temporal relationship, is unlabeled, and has unknown scientific plausibility. There is no information on any other factors potentially associated with the event(s). 20210801145-covid-19 vaccine ad26.cov2.s-maternal exposure during pregnancy. This event(s) is considered not related. The event(s) has a compatible/suggestive temporal relationship, is unlabeled, and has unknown scientific plausibility. There are other factors more likely to be associated with the event(s) than the drug. Specifically: SPECIAL SITUATIONS