POLYHYDRAMNIOS; MATERNAL EXPOSURE DURING PREGNANCY; CHILLS; FEVER; This solicited pregnancy report received from a consumer concerned a 33 year old female of unspecified ethnicity. The patient was enrolled in a non-company sponsored study: COVID 19 Vaccines International Pregnancy Exposure Registryt number: private). The patient's weight was 56.689 kilograms, and height was 173 centimeters. The patient's past medical history included: miscarriage, and concurrent conditions included: multigravida, no history of tobacco, alcohol, no recreational drug use, and other pre-existing medical conditions included: The patient was pregnant at the time of vaccination. The patient had para 2 and gravida 3. The patient initiated treatment with covid-19 vaccine ad26.cov2.s (suspension for injection, route of admin, and batch number were not reported) dose was not reported, 1 total, administered on 20-MAR-2021 for covid-19 immunisation. The batch number was not reported and has been requested. Concomitant medications included ascorbic acid/calcium pantothenate/cyanocobalamin/ergocalciferol/nicotinamide/pyridoxine hydrochloride/retinol palmitate/riboflavin/thiamine mononitrate. The patient's first day of the last menstrual period (LMP) was calculated to be 12-Feb-2021.  On 20-Mar-2021, at gestational age five weeks and one day, the patient received the vaccine and experienced maternal exposure during pregnancy. On same day, the patient experienced chills and fever. Laboratory data included: Body temperature (NR: not provided) 102 F. On 15-Sep-2021, the patient was diagnosed with polyhydramnios. On 15-Nov-2021, at gestational age 39 weeks and three days, she was admitted to hospital and spent one day in hospital for the delivery. The patient delivered vaginally a live, male, full-term neonate. The neonate's birth weight was 8 pounds, body length 21 inches.  The action taken with covid-19 vaccine ad26.cov2.s was not applicable. The patient recovered from maternal exposure during pregnancy on 15-NOV-2021, and chills, and fever on 21-MAR-2021, and the outcome of polyhydramnios was not reported. The reporter provided no causality assessment. Company causality between covid-19 vaccine ad26.cov2.s, and polyhydramnios, and maternal exposure during pregnancy was not related, and between covid-19 vaccine ad26.cov2.s, and chills, and fever was related.  This report was serious (Other Medically Important Condition).  Additional information was received from consumer on 03-MAR-2022. The following information was updated and incorporated into the case narrative: Case upgraded to serious, New event Polyhyramnios added with seriousness criteria of other medically important condition, cessation date added for the event maternal exposure during pregnancy, Medical history added, pregnancy details updated (outcome, estimated delivery date, end of pregnancy date, para details updated), child information (sex, weight, height, delivery method) added, patient details (race) added and lab data added.; Sender's Comments: V1:  The follow up information in this version updates New Event Polyhydramnios, cessation date added for the event maternal exposure during pregnancy, Medical history added, pregnancy details, child information, patient details. Causality for the event polyhydramnios assessed.   20211241193-covid-19 vaccine ad26.cov2.s-Polyhydramnios. The event(s) shows an incompatible temporal relationship. Therefore, this event(s) is considered not related.