Original sources

Original scientific reports of mPox in pregnancy. Summaries, links, full texts, & citations, along the lines of our Covid-19 database (click here). No opinion, reviews, or guidelines. Just primary sources. Duplicates and possible duplicates flagged. Regularly updated by Susan Bewley, Keelin O’Donoghue, Kate Walker and me. For news reports of mPox in pregnancy click here.

We’ve not listed primary sources for smallpox vaccine in pregnancy, but see reference list of study 10.

21 August 2024 – In view of the recent upsurge (click here for WHO update) we are updating this list. New studies 12-20, and 24 – 26 are all from past epidemics. Study 23 may include up to five cases from the current epidemic.

Update 29 September – MP 28 updated.

Update 30 August – MP 34 and MP 35, two authoritative reviews, added.

MP study 35 – authoritative review from NEJM

Click here or full text). Citation: Nachega JB, Mohr EL, Dashraath P, Mbala-Kingebeni P, Anderson JR, Myer L, Gandhi M, Baud D, Mofenson LM, Muyembe-Tamfum JJ; Mpox Research Consortium (MpoxReC). Mpox in Pregnancy – Risks, Vertical Transmission, Prevention, and Treatment. N Engl J Med. 2024 Aug 28. doi: 10.1056/NEJMp2410045. Epub ahead of print. PMID: 39197097.

MP study 34 – authoritative review from the Lancet

(click Paediatric, maternal, and congenital mpox: a systematic review and meta-analysis – The Lancet Global Health or full text). Citation: Sanchez Clemente N, Coles C, Paixao ES, Brickley EB, Whittaker E, Alfven T, Rulisa S, Agudelo Higuita N, Torpiano P, Agravat P, Thorley EV, Drysdale SB, Le Doare K, Muyembe Tamfum JJ. Paediatric, maternal, and congenital mpox: a systematic review and meta-analysis. Lancet Glob Health. 2024 Apr;12(4):e572-e588. doi: 10.1016/S2214-109X(23)00607-1. Epub 2024 Feb 21. PMID: 38401556.

Update 24 August – MP studies 31 to 33 added

MP study 33 – authoritative review

All cases previously reported (click here or full text). Citation: Schwartz DA, Ha S, Dashraath P, Baud D, Pittman PR, Adams Waldorf KM. Mpox Virus in Pregnancy, the Placenta, and Newborn. Arch Pathol Lab Med. 2023 Jul 1;147(7):746-757. doi: 10.5858/arpa.2022-0520-SA. PMID: 36857117.

MP study 32 – review of outcomes by viral clade

All cases previously reported (click here or full text). Citation: Schwartz DA, Pittman PR. Mpox (Monkeypox) in Pregnancy: Viral Clade Differences and Their Associations with Varying Obstetrical and Fetal Outcomes. Viruses. 2023 Jul 28;15(8):1649. doi: 10.3390/v15081649. PMID: 37631992; PMCID: PMC10458075.

MP study 31 – 27 cases from USA

Collected by CDC up to February 28, 2023. 18 pregnancies ongoing or no reported outcome. Of the other nine, three ended in pregnancy loss (<20 weeks) and six in live birth (click here or full text). Although not explicitly stated, these probably include the 23 cases reported in MP study 12. Citation: Neelam V, Olsen E, Roth N, Newton S, Galang R, Hufstetler K, Zilversmit Pao L, Peterson B, Bachmann L, Tong V, Meaney-Delman D, Ellington S. Pregnancy Characteristics and Birth Outcomes in People with Mpox Infection During Pregnancy – Surveillance for Emerging Threats to Pregnant People and Infants Network. AJOH MFM Abstract| Volume 230, ISSUE 2, SUPPLEMENT , S626, February 2024 DOI:https://doi.org/10.1016/j.ajog.2023.09.025

Update 23 August – studies 27 to 30 added. Study 27, not a primary source, included because authoritative. Study 29 included because it may have been misreported in a review. Study 30 is the previously unaccessed primary source for study 3.

MP study 30 – Primary source for Study 3

A 44-year-old woman from North Zaire contracted mPox on 11 August 1983 and recovered. On 23 September, she gave birth to a premature girl, (BW <1.5 Kg) at about the 7th month. The infant was born with generalized skin lesions characteristic for monkeypox, and the scabs had fallen off by October 7. The child died of malnutrition on November 9. (click here or full report chap 5). Citation: Jezek Z, Fenner F. Human monkeypox. New York (NY): Karger; 1988. Chapter V. Clinical Features of Human Monkeypox. p 59.

MP study 29 – a possible case from Zaire

A 2023 review (click here or full text) reported a first trimester case from Zaire, and referenced this source (click here or full report). However that paper does not report any pregnancy cases. (Note we were originally unable to access another primary source with the same first author, Jezek M. However MP study 3‘s primary source, MP study 30, has now been confirmed ). Review Citation: D’Antonio F, Pagani G, Buca D, Khalil A. Monkeypox infection in pregnancy: a systematic review and metaanalysis. Am J Obstet Gynecol MFM. 2023 Jan;5(1):100747. doi: 10.1016/j.ajogmf.2022.100747. Epub 2022 Sep 9. PMID: 36096413; PMCID: PMC9555294. And Primary source citation: Jezek Z, Szczeniowski M, Paluku KM, Mutombo M. Human monkeypox: clinical features of 282 patients. J Infect Dis. 1987 Aug;156(2):293-8. doi: 10.1093/infdis/156.2.293. PMID: 3036967.

MP study 28 – nine cases from Congo

One woman who had birthed by Caesarean two weeks earlier was admitted with mPox and peritonitis and died. Eight other pregnant women are reported, of whom one miscarried in the first trimester and three between 10 and 20 weeks. In one of the latter cases mPox skin lesions were noted on the fetus. The pregnancy outcomes of the other four are not reported (click here or full text). Citation: Leandre Murhula Masirika, David F. Nieuwenhuijse, Pacifique Ndishimye, Jean Claude Udahemuka, Bilembo Kitwanda Steeven, Nzigire Barhatwira Gisèle, Jean Pierre Musabyimana, Baganda Ntahuma Daniel, Théophile Kiluba wa Kiluba, Franklin Kumbana Mweshi, Polepole Ngabo, Theophile Tambala, Mazambi Mambo Divin, Bahati Mutalemba Chance, Léandre Mutimbwa Mambo, Leonard Schuele, Justin Bengehya Mbiribindi, Gustavo Sganzerla Martinez, David J Kelvin, Gaston Lubambo Maboko, Bas B. Oude Munnink, Trudie Lang, Frank M. Aarestrup, Christian Gortazar, Marion Koopmans, Freddy Belesi Siangoli. Mapping the distribution and describing the first cases from an ongoing outbreak of a New Strain of mpox in South Kivu, Eastern Democratic Republic of Congo between September 2023 to April 2024. medRxiv 2024.05.10.24307057; doi: https://doi.org/10.1101/2024.05.10.24307057

Update 29 Sept 2024. Study 28 has been updated, albeit still a preprint (click here or full text). The update reports 14 pregnant women, of whom 8 had a fetal loss.

MP Study 27 – a review article

Comment by David A Schwartz, a leading authority on the mPox epidemics in West Africa, on the 2023-24 epidemic pregnancy risks (click here or full text). Not a primary source. Citation: Schwartz DA. High Rates of Miscarriage and Stillbirth among Pregnant Women with Clade I Mpox (Monkeypox) Are Confirmed during 2023-2024 DR Congo Outbreak in South Kivu Province. Viruses. 2024 Jul 13;16(7):1123. doi: 10.3390/v16071123. PMID: 39066285; PMCID: PMC11281436.

MP study 26 – PAHO situation report Nov 2022

This report from the Americas refers to 31 cases in pregnant women, collected by WHO, five of whom were hospitalised (click here or full text). These probably overlap with the WHO cases in MP study 23. Citation: Situation Report on Monkeypox Multi-Country Outbreak Response – Region of the Americas. N.5 – 13 December 2022. Accessed 22 August 2024

MP study 25 – two cases from Nigeria

One pregnancy loss following ruptured membranes at 16 weeks.This case may be the same as the one reported in MP study 2. One female baby aged 28 days with bronchopneumonia and encephalitis and died after 8 days (click here or full text). Citation: Ogoina D, Iroezindu M, James HI, Oladokun R, Yinka-Ogunleye A, Wakama P, Otike-Odibi B, Usman LM, Obazee E, Aruna O, Ihekweazu C. Clinical Course and Outcome of Human Monkeypox in Nigeria. Clin Infect Dis. 2020 Nov 5;71(8):e210-e214. doi: 10.1093/cid/ciaa143. PMID: 32052029.

MP study 24 – two cases from the Share-Net collaboration

Both pregnancies ongoing. Country not reported (click here or full text). Citation: Thornhill JP, Palich R, Ghosn J, Walmsley S, Moschese D, Cortes CP, Galliez RM, Garlin AB, Nozza S, Mitja O, Radix AE, Blanco JL, Crabtree-Ramirez B, Thompson M, Wiese L, Schulbin H, Levcovich A, Falcone M, Lucchini A, Sendagorta E, Treutiger CJ, Byrne R, Coyne K, Meyerowitz EA, Grahn AM, Hansen AE, Pourcher V, DellaPiazza M, Lee R, Stoeckle M, Hazra A, Apea V, Rubenstein E, Jones J, Wilkin A, Ganesan A, Henao-Martínez AF, Chow EJ, Titanji BK, Zucker JE, Ogoina D, Orkin CM; Share-Net writing group. Human monkeypox virus infection in women and non-binary individuals during the 2022 outbreaks: a global case series. Lancet. 2022 Dec 3;400(10367):1953-1965. doi: 10.1016/S0140-6736(22)02187-0. Epub 2022 Nov 17. PMID: 36403584; PMCID: PMC9671743.

MP study 23 – 60 cases in the WHO database

The date of infection is not reported, although 55 cases had been included before March 2024, so presumably were infected in earlier epidemics. Of the total 5, 12, and 10 were in the 1st, 2nd & 3rd trimesters respectively (33 unknown trimester, none post-partum). Median age 27.5 years. 15 hospitalized. None known to be admitted to ICU and none known to have died. No baby outcomes reported (click here). Citation: 2022-24 Mpox Outbreak: Global Trends. Geneva: World Health Organization, 2024. Available online: https://worldhealthorg.shinyapps.io/mpx_global/ Accessed 22 August 2024

MP study 22 – 4 cases from Democratic Republic of Congo

Further details of the cases reported in MP study 1 (click here or full text). Citation: Pittman PR, Martin JW, Kingebeni PM, Tamfum JM, Mwema G, Wan Q, Ewala P, Alonga J, Bilulu G, Reynolds MG, Quinn X, Norris S, Townsend MB, Satheshkumar PS, Wadding J, Soltis B, Honko A, Güereña FB, Korman L, Patterson K, Schwartz DA, Huggins JW; Kole Human Mpox Infection Study Group. Clinical characterization and placental pathology of mpox infection in hospitalized patients in the Democratic Republic of the Congo. PLoS Negl Trop Dis. 2023 Apr 20;17(4):e0010384. doi: 10.1371/journal.pntd.0010384. PMID: 37079637; PMCID: PMC10153724.

MP study 21 – Case report from Congo

Further detail of one of the cases reported in MP study 1 (click here or full text). Citation: Schwartz DA, Mbala-Kingebeni P, Patterson K, Huggins JW, Pittman PR. Congenital Mpox Syndrome (Clade I) in Stillborn Fetus after Placental Infection and Intrauterine Transmission, Democratic Republic of the Congo, 2008. Emerg Infect Dis. 2023 Nov;29(11):2198-2022. doi: 10.3201/eid2911.230606. Epub 2023 Sep 13. PMID: 37705112; PMCID: PMC10617360.

MP study 20 – Case report from Spain

A 24-year-old was infected in the first trimester and delivered a healthy baby normally at term (click here or full text). Citation: García-Hernández L, Hernández-Aceituno A, Moreno Saavedra RJ, Larumbe-Zabala E. Case report: clinical presentation of Monkeypox in pregnancy. Rev Clin Esp (Barc). 2024 Apr;224(4):245-247. doi: 10.1016/j.rceng.2024.02.009. Epub 2024 Feb 23. PMID: 38401666.

MP study 19 – two case reports from USA

Both cases, identified retrospectively from stored serum samples, had normal births at term (click here or full text). Citation: Contag CA, Renfro ZT, Lu J, Shen S, Karan A, Solis D, Huang C, Sahoo MK, Yamamoto F, Jones MS, Lin J, Levy V, Pinsky BA. Prevalence of Mpox (Monkeypox) in patients undergoing STI screening in northern California, April-September 2022. J Clin Virol. 2023 Jul;164:105493. doi: 10.1016/j.jcv.2023.105493. Epub 2023 May 15. PMID: 37220710; PMCID: PMC10184869.

MP study 18 – two case reports from USA

Both cases, identified retrospectively from stored serum samples, had normal births at term (click here or full text). Same two cases as reported in study 17. Citation: Renfro ZT, Contag CA, Lu J, Solis D, Huang C, Sahoo MK, Yamamoto F, Mah J, Jones MS, Lin J, Levy V, Pinsky BA. Two cases of MPXV infection during pregnancy in heterosexual cisgender women without classic cutaneous lesions, Northern California, 2022. IDCases. 2023 Aug 21;33:e01881. doi: 10.1016/j.idcr.2023.e01881. PMID: 37680215; PMCID: PMC10480306.

MP study 17 – Case report from USA

Infected at 31 weeks and treated with tecovirimat (click here or full text). Normal birth at 39 weeks. Baby had a positive IgG test no clinical signs. Citation: Sampson MM, Magee G, Schrader EA, Dantuluri KL, Bukhari A, Passaretti C, Temming L, Leonard M, Philips JB, Weinrib D. Mpox (Monkeypox) Infection During Pregnancy. Obstet Gynecol. 2023 May 1;141(5):1007-1010. doi: 10.1097/AOG.0000000000005170. Epub 2023 Mar 15. PMID: 36928418.

MP study 16 – No pregnancies reported in the Brazil 2022 outbreak

Among 10,169 cases (648 women) no pregnancies were reported (click here or full text). Citation: Souza IN, Pascom ARP, Spinelli MF, Dias GB, Barreira D, Miranda AE. Demographic and clinical characteristics of people diagnosed with active sexually transmitted infections among monkeypox cases in Brazil: the 2022 outbreak. Rev Inst Med Trop Sao Paulo. 2024 Apr 5;66:e20. doi: 10.1590/S1678-9946202466020. PMID: 38597520; PMCID: PMC11000497.

MP study 15 – No pregnancies among 108 infected women in Sao Paolo.

From Brazil (click here or full text). No pregnancies reported among 108 infected women. Citation: Coutinho C, Secco Torres Silva M, Torres TS, Peixoto E, Avelar Magalhães M, Wagner Cardoso S, Nazário G, Mendonça M, Menezes M, Almeida PM, Dias de Brito de Carvalho PR, Bia Bedin S, Almeida AM, Carvalho S, Gonçalves Veloso V, Grinsztejn B, Velasque L; INI-Fiocruz Mpox Study Group. Characteristics of women diagnosed with mpox infection compared to men: A case series from Brazil. Travel Med Infect Dis. 2023 Nov-Dec;56:102663. doi: 10.1016/j.tmaid.2023.102663. Epub 2023 Nov 8. PMID: 37949306.

MP study 14 – Case report from UK

Mother, father and newborn baby infected (click here or full text). The baby also had adenovirus co-infection, and required neonatal intensive care and ventilation. All three recovered. Citation: Ramnarayan P, Mitting R, Whittaker E, Marcolin M, O’Regan C, Sinha R, Bennett A, Moustafa M, Tickner N, Gilchrist M, Kershaw A, Rampling T; NHS England High Consequence Infectious Diseases (Airborne) Network. Neonatal Monkeypox Virus Infection. N Engl J Med. 2022 Oct 27;387(17):1618-1620. doi: 10.1056/NEJMc2210828. Epub 2022 Oct 12. PMID: 36223535.

MP study 13 – Three cases in women from Argentina. No pregnancies

Two were in cis-women one in a trans-woman. No pregnancies. Click here or full text) Citation: Sánchez Doncell J, Lemos M, Francos J JL, González Montaner P. Viruela símica: características en población femenina, Buenos Aires, Argentina [Monkeypox: characteristics in female population, Buenos Aires, Argentina]. Medicina (B Aires). 2024;84(1):143-147. Spanish. PMID: 38271941.

MP study 12 – 23 cases during or within 3 weeks of pregnancy

From the USA. Of the 21 cases diagnosed during pregnancy, three had reported outcomes, two full-term deliveries without complications (including no transmission to the infant) and one spontaneous abortion at 11 weeks (click here or full text). The newsborns of two postnatal cases developed lesions within 1 week. Both newborns received oral tecovirimat within 48 hours and were treated for 10–14 days; one received VIGIV. Both newborns responded to treatment, appeared to be in good health, and were discharged home. Citation: Oakley, L.P.; Hufstetler, K.; O’Shea, J.; Sharpe, J.D.; McArdle, C.; Neelam, V.; Roth, N.M.; Olsen, E.O.; Wolf, M.; Pao, L.Z.; et al. Mpox Cases Among Cisgender Women and Pregnant Persons—United States, May 11–November 7, 2022. MMWR Morb. Mortal Wkly. Rep. 2023, 72, 9–14.

30 July 2022 – MP study 11 added

MP study 11 – a monkeypox & pregnancy registry

A group from Switzerland who run a registry for emergent infectious pathogens and pregnancy (click here) have expanded it to collect cases of monkeypox in pregnancy (cleck here or study). Citation: Pomar L, Favre G, Baud D. Monkeypox infection during pregnancy: European registry to quantify maternal and fetal risks. Ultrasound Obstet Gynecol. 2022 Jul 9. doi: 10.1002/uog.26031. Epub ahead of print. PMID: 35809242.

13 June 2022 – MP studies 7 to 10 added

MP study 10 – 376 women in smallpox vaccine in pregnancy registry

As of September 2006, pregnancy outcome data were available for 376 women enrolled in the Smallpox Vaccine in Pregnancy Registry (click here or study). Rates of pregnancy loss (11.9%), preterm birth (10.7%), or birth defects (2.8%), were judged comparable with those in healthy referent populations. No cases of fetal vaccinia were identified. Citation: Ryan MA, Seward JF; Smallpox Vaccine in Pregnancy Registry Team. Pregnancy, birth, and infant health outcomes from the National Smallpox Vaccine in Pregnancy Registry, 2003-2006. Clin Infect Dis. 2008 Mar 15;46 Suppl 3:S221-6. doi: 10.1086/524744. PMID: 18284362.

MP study 9 – 13 pregnancies in studies of Imvanex vaccine

Thirteen pregnancies occurred during five studies of Imvanex smallpox vaccine (Live Modified Vaccinia Virus Ankara). One was terminated with an elective abortion and one ended as spontaneous abortion. All others were followed up and all women gave birth to healthy babies (click here or study p109). These cases may overlap with those in study 7. Citation: European Medicines Agency 369203/2013 Committee for Medicinal Products for Human Use (CHMP) 30 May 2013. Accessed 13 June 2022

MP study 8 – no data on tecovirimat in pregnancy

Tecovirimat SIGA is indicated for the treatment of orthopoxvirus disease (smallpox, monkeypox,
cowpox, and vaccinia complications). There are no data on its use in pregnant women (click here or study p 30). Citation: European Medicines Agency 703119/2021. Committee for Medicinal Products for Human Use (CHMP)11 November 2021. Accessed 13 June 2022

MP study 7 – 14 pregnant women in trial of live, non-replicating smallpox and monkeypox vaccine

In this Federal Drug Administration report 24 women became pregnant during controlled trials of the Live, Non-replicating Smallpox and Monkeypox Vaccine, Modified Vaccinia Ankara BN (MVA-BN). 14 had received active vaccine or placebo. Five gave birth to healthy infants, and three had elective (non-medically indicated) abortions. In the MVA-BN group one had fetal death at ~12 weeks and one had a spontaneous abortion. In the placebo group, two had spontaneous abortions. Four women were lost to follow-up and the pregnancy outcomes are unknown (click here or study p 123). Citation: JYNNEOS, also referred to as Modified Vaccinia Virus Ankara–Bavarian Nordic (MVA-BN) FDA biologics license application. Clinical Review Memorandum 9/19/2019. Accessed 13 June 2022

11 June 2022 – MP study 5 added

MP Study 6 – five cases from the Democratic Republic of Congo

This preprint includes five pregnancy cases (click here or study), of which four had been previously described in MP study 1. No details are given of the new case except that this sentence in the abstract “fetal death occurred in 4 of 5 (80%) patients who were pregnant at admission” implies that the fetus died. Citation: Phillip R. Pittman, James W. Martin, Placide Mbala Kingebeni, Jean-Jacques Muyembe Tamfum, Qingwen Wan, Mary G. Reynolds, Xiaofei Quinn, Sarah Norris, Michael B. Townsend, Panayampalli S. Satheshkumar, Bryony Soltis, Anna Honko, Fernando B. Güereña, Lawrence Korman, John W. Huggins. Clinical characterization of human monkeypox infections in the Democratic Republic of the Congo. medRxiv 2022.05.26.22273379; doi: https://doi.org/10.1101/2022.05.26.22273379

8 June 2022 – MP studies 1-5 added

MP study 5 – No cases in pregnant women in present outbreak

As of 4 June 2022 no cases of monkeypox in pregnant women have been reported by WHO, either in endemic or non endemic areas (click here). Note the report does not explicitly state that no cases in pregnancy have ocurred. Citation: The World Health Organisation. Multi-country monkeypox outbreak: situation update. 4 June 2022. Accessed 8 June 2022

MP study 4 – no pregnant women in the 2003 USA outbreak

No infected pregnant women were reported in any of the CDC reports of the 2003 United States outbreak of monkeypox (click here for the latest update). Citation: Update: multistate outbreak of monkeypox—Illinois, Indiana, Kansas, Missouri, Ohio, and Wisconsin, 2003. MMWR Morb Mortal Wkly Rep 2003;52:589–90.

MP study 3 – secondary source for a case report from Zaire

“One case of probable congenital monkeypox in Zaire has been described. At approximately 24 weeks of
gestation, a pregnant woman developed a febrile illness with a rash; monkeypox virus was subsequently isolated from a vesicular lesion. Six weeks later she delivered a 1,500-g female infant with a generalized skin rash resembling monkeypox. The child died of malnutrition at 6 weeks of age.” The source is given as Jezek Z, Fenner F. Human monkeypox. New York (NY): Karger; 1988. [Not accessed]. Citation: Jamieson DJ, Cono J, Richards CL, Treadwell TA. The role of the obstetrician-gynecologist in emerging infectious diseases: monkeypox and pregnancy. Obstet Gynecol. 2004 Apr;103(4):754-6. doi: 10.1097/01.AOG.0000114987.76424.6d. PMID: 15051569.

Update 23 August 2024 MP study 30, the previously un-accessed source, added.

MP study 2 – one case from Nigeria in 2017-18

One woman who was pregnant during her illness had a spontaneous abortion at 26 weeks (click here or study). Citation: Yinka-Ogunleye A, Aruna O, Dalhat M, Ogoina D, McCollum A, Disu Y, Mamadu I, Akinpelu A, Ahmad A, Burga J, Ndoreraho A, Nkunzimana E, Manneh L, Mohammed A, Adeoye O, Tom-Aba D, Silenou B, Ipadeola O, Saleh M, Adeyemo A, Nwadiutor I, Aworabhi N, Uke P, John D, Wakama P, Reynolds M, Mauldin MR, Doty J, Wilkins K, Musa J, Khalakdina A, Adedeji A, Mba N, Ojo O, Krause G, Ihekweazu C; CDC Monkeypox Outbreak Team. Outbreak of human monkeypox in Nigeria in 2017-18: a clinical and epidemiological report. Lancet Infect Dis. 2019 Aug;19(8):872-879. doi: 10.1016/S1473-3099(19)30294-4. Epub 2019 Jul 5. PMID: 31285143.

MP study 1 – four cases from the Democratic Republic of Congo

Four pregnant women treated in the General Hospital of Kole, in Sankuru District, Kasai Orientale Province, from March 2007 to July 2011. One was infected at six weeks (miscarriage at 9 weeks), one at 6-7 weeks (miscarriage at 8-9 weeks), one at 14 weeks (livebirth at term), and one at 18 weeks (fetal death at 21 weeks) (click here or study). Citation: Mbala PK, Huggins JW, Riu-Rovira T, Ahuka SM, Mulembakani P, Rimoin AW, Martin JW, Muyembe JT. Maternal and Fetal Outcomes Among Pregnant Women With Human Monkeypox Infection in the Democratic Republic of Congo. J Infect Dis. 2017 Oct 17;216(7):824-828. doi: 10.1093/infdis/jix260. PMID: 29029147.