Human metapneumovirus infection in pregnancy: A systematic review of cohort studies and case reports

Table 1 Characteristics of the included studies

Ref.	Country	Setting and design	Study period	N pregnant women in cohort	N pregnant with hMPV	GA at infection (pregnancy cases)	hMPV diagnostic method	Maternal clinical course (pregnancy hMPV cases)	Obstetric outcomes (pregnancy hMPV cases)	Neonatal outcomes (pregnancy hMPV cases)
Haas et al[20], 2012	The Netherlands	ICU-based case series of three adult patients with RT-PCR-confirmed hMPV respiratory infection requiring intensive care; one of the three was a pregnant woman at 30 weeks’ gestation with severe respiratory illness and suspected pyelonephritis	Cases admitted between January 2010 and March 2011 (winter seasons)	Not applicable as a defined pregnancy cohort; report describes three adult ICU patients, including one pregnant woman	1 pregnant woman with hMPV infection (among three ICU patients)	30 weeks’ gestation at onset of illness (G1P0, otherwise uncomplicated pregnancy)	Nasopharyngeal swab processed in general respiratory virus culture and tested by RT-PCR; positive for hMPV (Ct 24 in throat, Ct 33 in nose). Other respiratory viruses (adenovirus, influenza A/B, parainfluenza 1-3, rhinovirus, RSV A/B) were negative	Presented with 3 days of fever and right flank pain. Urinalysis showed leukocyturia and bacteriuria, and she was treated empirically for pyelonephritis with amoxicillin-clavulanate, escalated to a third-generation cephalosporin and then meropenem due to clinical deterioration and suspected sepsis. Despite a normal initial chest X-ray, she developed respiratory insufficiency requiring 40% oxygen and ICU transfer. On admission, she was febrile (39 °C), tachycardic, hypotensive, and tachypnoeic, with mild hypoxaemia on arterial blood gases. CT pulmonary angiography excluded pulmonary embolism but showed bilateral alveolar consolidations. Urine culture grew Escherichia coli susceptible to amoxicillin, and RT-PCR was positive for hMPV. She was treated with high-flow oxygen and antibiotics, without need for mechanical ventilation, and improved within 3 days, returning to the obstetric ward	Serial fetal monitoring during ICU stay (cardiotocography) remained normal, with no signs of fetal distress. The pregnancy continued uneventfully after maternal recovery. Delivery occurred about 6 weeks later, around 36 weeks’ gestation	A healthy girl was born 6 weeks after ICU admission. No obstetric complications (e.g., preeclampsia, postpartum haemorrhage) or neonatal respiratory compromise or infection were reported
Lenahan et al[13], 2017	Nepal	Rural community-based cohort, nested in randomized trial of maternal influenza vaccination; prospective active weekly home surveillance for febrile respiratory illness from mid-pregnancy to 6 months postpartum	Enrolment 2011-2013; follow-up to 2014	3693 pregnant women (15-40 years, 17-34 weeks at enrolment)	25 during pregnancy (55 total including postpartum episodes)	Median 32.5 weeks (IQR 22-37) at hMPV illness	RT-PCR on mid-nasal swabs collected during influenza-like illness (subjective fever plus ≥ 1 of cough, myalgia, rhinorrhea, sore throat)	All had fever; most had cough (about ⅔), rhinorrhea and myalgia (about ½), and sore throat (about 40%); median total symptom duration 5 days (fever 3 days, cough 2 days); 48% of pregnant cases sought medical care; no hospitalizations or maternal deaths among pregnancy hMPV cases; about half had viral co-infection (mainly rhinovirus)	All 25 pregnancies ended in livebirth; preterm birth in 2/25 (8%); low birthweight (< 2500 g) in 5/25 (25%); small for gestational age in 12/25 (about 63%), with increased risk vs women without fever (RR: 1.7, 95%CI: 1.0-2.6); median gestational age at delivery 40 weeks (IQR 38-41) and median birthweight 2.8 kg, similar to non-hMPV women	All infants liveborn; no neonatal deaths attributed to maternal hMPV; no clear difference in median birthweight or gestational age vs non-hMPV, but higher proportion small for gestational age; neonatal hMPV described mainly in context of postpartum maternal infection, not antenatal
Fuchs et al[14], 2017	United States (Brooklyn, New York)	Single-center case report from a tertiary hospital (Maimonides Medical Center) describing an 18-year-old primigravid woman in late-preterm pregnancy who developed severe hMPV pneumonia with ARDS requiring intensive care, mechanical ventilation and venovenous ECMO	Case diagnosed in late March (published 2017); exact calendar year not specified	Not a defined pregnancy cohort; report focuses on one pregnant patient with severe hMPV infection and ARDS	1 pregnant woman with hMPV infection at 36 + 2 weeks’ gestation	36 2/7 weeks of gestation at presentation with premature contractions, fever, nausea and vomiting; late-preterm stage with underlying mild intermittent asthma and morbid obesity (BMI 50 kg/m²)	Respiratory viral panel (multiplex PCR) on respiratory specimens, positive for human metapneumovirus; influenza and other common respiratory viruses were negative. Diagnosis made on postoperative day 3	On admission she had fever (101.9 °F), tachycardia (130-140 bpm), tachypnoea (24/minutes), and hypoxia (SpO2 91%-93% on room air) after a sick contact, with a normal chest examination. She was treated empirically for community-acquired pneumonia, influenza, and asthma exacerbation (ceftriaxone, azithromycin, oseltamivir, methylprednisolone, ipratropium, oxygen); chest X-ray was negative and CT angiography showed only small-airway disease. Her respiratory status deteriorated, requiring ICU transfer and high-setting BiPAP. When intubation became unavoidable, she underwent delivery under general anaesthesia. Postoperatively, she developed pulmonary oedema and refractory hypoxaemia consistent with ARDS, and venovenous ECMO was initiated for 2 days. She was extubated on postoperative day 4, decannulated from ECMO on day 6, completed a 10-day course of broad-spectrum antibiotics, and was discharged home on postoperative day 10 on antihypertensives and oral antibiotics	Obstetric course at presentation was complicated by fetal growth restriction (< 10th percentile) and oligohydramnios on ultrasound, but with normal umbilical artery Dopplers and reassuring biophysical profile (8/10). Despite these findings, initial management was expectant because of the hope of maternal respiratory improvement and the need to avoid general anaesthesia. As respiratory failure progressed on hospital day 2, a decision was made to proceed with delivery if intubation was required. Immediately before caesarean delivery, the patient developed severe-range blood pressures and was diagnosed with preeclampsia with severe features; magnesium sulfate was started. She underwent primary caesarean delivery under general anaesthesia with immediate intubation. Intraoperative findings included lower uterine atony, which responded to uterotonic agents; estimated blood loss was 800 mL. No other obstetric complications were reported postoperatively	A female neonate weighing 2530 g (19th percentile) was delivered at 36+ weeks’ gestation. Apgar scores were 2 and 9 at 1 and 5 minutes, respectively. At birth, the neonate required stimulation, nasal continuous positive airway pressure, oral suctioning and brief face-mask ventilation; nasal CPAP was weaned off after 2 minutes. The neonate was admitted to the neonatal intensive care unit in stable condition. No neonatal infection or respiratory failure attributed to hMPV was reported and the neonatal course was described as stable
Emont et al[15], 2019	United States (Rhode Island)	Single-center case report from Women and Infants Hospital of Rhode Island describing two pregnant women in the third trimester with respiratory illness and positive multiplex RPP for hMPV; one with asthma developed progressive respiratory failure requiring ICU admission, and the other developed superimposed bacterial pneumonia due to beta-lactamase producing Haemophilus influenzae	Not precisely specified; both cases occurred in late March during winter–early spring respiratory virus season	Not a defined pregnancy cohort; report focuses on two pregnant women with hMPV infection	2 pregnant women with hMPV infection (case 1 at 29 + 5 weeks; case 2 at 31 + 0 weeks)	Case 1: 40-year-old G10P2072 at 29 weeks 5 days’ gestation with mild intermittent asthma. Case 2: 36-year-old G4P2102 at 31 weeks’ gestation with multiple comorbidities (tobacco use, seizure disorder, Charcot-Marie-tooth, history of opioid dependence, bipolar disorder)	Both patients were tested using the GenMark Dx ePlex multiplex RPP on respiratory specimens. Initial RPP in Case 1 was negative; repeat RPP during worsening illness was positive only for hMPV. In case 2, RPP on admission for hypoxia was positive only for hMPV. Rapid influenza testing was negative when performed	Case 1: At 29 + 5 weeks she presented with dyspnoea, fever, cough, and myalgias; initial evaluation (normal exam, clear lungs, negative CXR/RPP/flu) led to discharge on prednisone for presumed asthma exacerbation. She returned 2 days later with worsening respiratory distress (HR: 120 bpm, RR: 32 minutes); repeat CXR showed left basilar atelectasis and small effusions. She required high-flow nasal cannula (45 L/minute, 100%) and ICU transfer; RPP was positive for hMPV. BiPAP was started on ICU day 2. Fever and new right lower lobe infiltrate on day 3 prompted broad-spectrum antibiotics, later de-escalated after negative cultures. She was diuresed for suspected pulmonary oedema, improved gradually, transferred from ICU on day 9, and discharged on day 16 off oxygen. Mechanical ventilation was not required. Case 2: At 31 weeks she initially had streptococcal pharyngitis treated with amoxicillin. Four days later she returned with cough and dyspnoea; SpO2 was 93% on room air with wheezes, and CXR was normal. RPP was positive for hMPV. She required 1-2 L/minutes oxygen and bronchodilators. On day 3, productive cough and crackles developed; sputum grew beta-lactamase-producing Haemophilus influenzae, prompting a switch from amoxicillin to ceftriaxone and then oral cefdinir. She remained stable without ICU care or ventilation and was discharged after clinical improvement	Case 1: Pregnancy continued after ICU admission and recovery from hMPV-related respiratory failure and suspected superimposed pneumonia. She subsequently went into spontaneous labour at 38 weeks 6 days’ gestation and had an uncomplicated spontaneous vaginal delivery. No preterm labour or hypertensive disorder was reported. Case 2: Pregnancy also continued after hospitalization for hMPV infection and Haemophilus influenzae pneumonia. She later had an elective repeat caesarean delivery at 39 weeks’ gestation. No obstetric complications such as preterm labour, preeclampsia, or postpartum haemorrhage were described	Case 1: Delivered a female infant weighing 3600 g at 38 + 6 weeks by spontaneous vaginal delivery; neonatal status was reported as uncomplicated. No neonatal respiratory compromise or infection was described. Case 2: Delivered a female infant weighing 3230 g at 39 + 0 weeks by elective repeat caesarean; neonatal condition was reported as normal with no neonatal respiratory illness or sepsis mentioned. Both infants were term and appropriate for gestational age
Shivarame Gowda et al[22], 2023	United Arab Emirates (Abu Dhabi)	Single-center case report from a district community hospital describing two pregnant women with acute respiratory illness and pneumonia, both found positive for hMPV on respiratory panel PCR, with respiratory distress and presumed superimposed bacterial pneumonia, requiring ICU-level care	Not clearly specified; cases described in a 2023 case report	Not applicable (case report); two pregnant women with hMPV are described	2 pregnant women with hMPV infection (case 1 at term gestation; case 2 at approximately 7 months’ gestation)	Case 1: 34-year-old G3P2 at term gestation. Case 2: 37-year-old at about 7 months’ gestation with ongoing pregnancy at discharge	Respiratory pneumonia panel PCR on respiratory samples, positive for hMPV in both cases; COVID-19 was excluded by rapid PCR in case 2	Case 1: She initially presented with cough, sore throat, fatigue and mild dyspnoea, with leukocytosis and mildly raised CRP. Six hours after caesarean delivery she developed acute respiratory distress with severe cough and frothy sputum. Examination and imaging showed bilateral wheeze, crepitations, pleural effusion and basal consolidation; labs revealed marked leukocytosis and elevated CRP, D-dimer and procalcitonin. She was transferred to ICU and treated with oxygen, bronchodilator nebulisations, anti-failure therapy and IV ceftriaxone plus vancomycin. Sputum culture grew normal flora. She improved clinically and radiologically and was discharged home on day 6 on oral antibiotics. Case 2: At seven months’ gestation she presented with fever, productive cough, severe dyspnoea and tachypnoea, with diffuse wheeze/crackles, leukocytosis and markedly elevated CRP. CT chest showed bilateral patchy ground-glass opacities. She was admitted to ICU and treated with oxygen, nebulisations, ceftriaxone, oseltamivir, azithromycin and supportive care. Respiratory PCR was positive for hMPV; sputum culture later showed normal flora. She improved by day 3, stepped down from ICU on day 4, CT on day 5 showed regressing opacities, and she was discharged on day 6 on oral antibiotics. Mechanical ventilation was not required in either case, and both women recovered	Case 1: Underwent caesarean section at term, delivering a healthy female infant weighing 3695 g. No obstetric complications such as preterm labour, pre-eclampsia or postpartum hemorrhage were reported. Case 2: Pregnancy continued throughout the hospitalization; fetal monitoring during maternal ICU stay showed reassuring fetal heart rate tracings, and no preterm labour or other obstetric complications were described during the admission	Case 1: Neonatal outcome explicitly reported as a healthy term infant (3695 g) following caesarean delivery, with no respiratory compromise or neonatal infection described. Case 2: No delivery occurred during hospitalization and neonatal outcomes are not reported; the fetus remained well by monitoring at the time of maternal discharge
Kittikraisak et al[21], 2025	Thailand	Prospective cohort of pregnant women (PRIME study) at two hospitals in Thailand; twice-weekly active surveillance for acute respiratory illness throughout pregnancy with self-collected midturbinate nasal swabs; primary analysis focused on RSV incidence and its association with perinatal outcomes, with descriptive data on hMPV	2017-2018 respiratory viral seasons	2764 fully enrolled pregnant women. Overall in the cohort (not virus-specific), about 8% had preterm delivery and about 7% had SGA infants	29 antenatal hMPV illness episodes among pregnant women (22 in 2017, 7 in 2018); overall incidence 23 per 10000 pregnant person-months (95%CI: 16-33)	Gestational age at individual hMPV illness episodes was not reported in detail. Trimester-specific hMPV incidences per 10000 person-months were: First trimester 24.3, second 20.9, third 25.0. Median gestational age at cohort enrollment was 10 weeks (IQR 7-14)	Real-time reverse transcription PCR on self-collected midturbinate nasal swabs from women with acute respiratory illness (new onset or worsening of ≥ 1 of myalgia, cough, runny nose/nasal congestion, sore throat, or difficulty breathing within 7 days)	Among hMPV illnesses, approximately 21% had measured fever > 100.4 °F, 34% reported inability to complete routine daily activities, 34% sought medical care, and none were hospitalized. Median hMPV illness duration was 10 days (IQR: 8-13). Overall, hMPV illnesses in pregnancy were generally mild to moderate, with functional limitation but no severe outcomes reported	The study did not conduct specific statistical analyses of pregnancy or delivery outcomes among women with hMPV illness. Reported figures for preterm birth (8%) and SGA (7%) apply to the entire cohort and are not stratified by hMPV status. Therefore, no relative risks or hazard ratios for preterm birth or SGA associated with hMPV can be extracted	Neonatal outcomes (e.g., SGA, preterm birth) were evaluated at the cohort level but not separately for infants of mothers with hMPV illness. No specific associations between antenatal hMPV and neonatal outcomes are presented, reflecting the small number of hMPV cases and the analytic focus on RSV
Manyam et al[16], 2025	United States (Georgia; referral from outside hospital)	Two-case case report from an academic tertiary care center (Medical College of Georgia, Augusta University) describing severe respiratory illness due to hMPV in the second trimester of pregnancy: One case managed on an obstetric service with inpatient observation and steroids, and one case of hMPV-associated ARDS requiring intubation, mechanical ventilation, prone positioning and intensive care	Not precisely specified; cases reported in a 2025 publication and occurred during winter-early spring respiratory virus season	Not a defined pregnancy cohort; report focuses on two individual pregnant patients	2 pregnant women with hMPV infection (case 1 at 19 + 1 weeks; case 2 at 24 + 5 to 25 + 0 weeks’ gestation)	Case 1: 49-year-old G9P2234 at 19 weeks 1 day gestation. Case 2: 22-year-old G2P0101 at 24 weeks 5 days at initial outside hospital presentation, transferred at 24 + 6 weeks and delivered at 25 + 0 weeks by emergent caesarean section	Both cases were diagnosed via multiplex respiratory PCR panels. Case 1: BioFire respiratory panel on a nasal swab performed after admission returned positive for hMPV following a benign initial work-up (normal chest X-ray, ECG and laboratory studies). Case 2: A respiratory panel at the outside hospital was positive for hMPV in the setting of radiographic right lower and middle lobe pneumonia; on transfer, additional testing for influenza and RSV was negative, and blood, urine and bronchoalveolar lavage cultures showed no growth	Case 1: At 19 + 1 weeks she presented with severe dyspnoea after a recent ED visit for similar symptoms. She was afebrile with normal oxygen saturation and unremarkable CXR, ECG, and labs. Treated with bronchodilators, IV methylprednisolone, and empiric ampicillin, she was later found to be hMPV-positive on BioFire panel. Management was supportive with 48 hours of IV steroids followed by an oral taper. She required neither oxygen nor ICU care and was discharged on hospital day 8 in stable condition. Case 2: At 24 + 5 weeks, with type 1 diabetes, CKD, and chronic hypertension, she developed progressive hypoxic respiratory failure due to hMPV pneumonia. Despite broad-spectrum antibiotics and diuretics, she deteriorated with ARDS requiring intubation, prone ventilation, and vasopressors, and was transferred at 24 + 6 weeks. With worsening maternal oxygenation and non-reassuring fetal status, emergent caesarean section was performed at 25 + 0 weeks. Postoperatively, she had reduced LVEF (36%-40%) and required dialysis for refractory acidosis. Gradual respiratory and renal recovery followed; she was extubated, weaned to low-flow oxygen, transitioned to oral heart failure therapy, and discharged on hospital day 12 on 2 L home oxygen with close follow-up	Case 1: No obstetric complications occurred during the index hospitalisation at 19 + 1 weeks. Following resolution of her respiratory symptoms, she was discharged with high-risk obstetric follow-up and ultimately delivered at term at an outside hospital; no details on mode of delivery, labour course or hypertensive or haemorrhagic complications were provided. Case 2: Maternal respiratory failure due to hMPV-associated ARDS prompted emergent caesarean delivery at 25 + 0 weeks’ gestation for non-reassuring fetal status in the setting of worsening maternal hypoxaemia. The postoperative course was complicated by transient systolic heart failure with reduced ejection fraction, dialysis-requiring metabolic acidosis and difficult-to-control hypertension, all of which improved with intensive care and medical management. No further obstetric events were reported after delivery	Case 1: The patient delivered at term at an outside hospital; the infant’s health status and detailed neonatal outcomes were not available to the authors. No perinatal loss was reported. Case 2: Delivery occurred at 25 + 0 weeks’ gestation; the article focuses on maternal course and does not provide detailed neonatal information (e.g., birthweight, Apgar scores, respiratory support, or survival to discharge). The neonate was extremely preterm, but specific short-term or long-term outcomes are not described

A/B: Influenza A or B; ARDS: Acute respiratory distress syndrome; BAL: Bronchoalveolar lavage; BiPAP: Bilevel positive airway pressure; BMI: Body mass index; CPAP: Continuous positive airway pressure; CRP: C-reactive protein; CT: Computed tomography; CXR: Chest X-ray; ECG: Electrocardiogram; ECMO: Extracorporeal membrane oxygenation; GA: Gestational age; hMPV: Human Metapneumovirus; HR: Heart rate; ICU: Intensive care unit; IQR: Interquartile range; IV: Intravenous; MRSA: Methicillin-resistant Staphylococcus aureus; PCR: Polymerase chain reaction; PRIME: Name of the parent cohort study (PRIME study on pregnancy and influenza); RPP: Respiratory pathogen panel; RR: Relative risk; RSV: Respiratory syncytial virus; RT-PCR: Reverse transcription polymerase chain reaction; SGA: Small for gestational age; SpO₂: Peripheral capillary oxygen saturation; LVEF: Left ventricular ejection fraction; CKD: Chronic kidney disease; ED: Emergency department; COVID-19: Coronavirus disease 2019.