Pat O’Brien

4.9k total citations · 6 hit papers
43 papers, 2.6k citations indexed

About

Pat O’Brien is a scholar working on Obstetrics and Gynecology, Pediatrics, Perinatology and Child Health and Public Health, Environmental and Occupational Health. According to data from OpenAlex, Pat O’Brien has authored 43 papers receiving a total of 2.6k indexed citations (citations by other indexed papers that have themselves been cited), including 22 papers in Obstetrics and Gynecology, 21 papers in Pediatrics, Perinatology and Child Health and 9 papers in Public Health, Environmental and Occupational Health. Recurrent topics in Pat O’Brien's work include COVID-19 Impact on Reproduction (12 papers), Maternal and fetal healthcare (9 papers) and Pregnancy and preeclampsia studies (7 papers). Pat O’Brien is often cited by papers focused on COVID-19 Impact on Reproduction (12 papers), Maternal and fetal healthcare (9 papers) and Pregnancy and preeclampsia studies (7 papers). Pat O’Brien collaborates with scholars based in United Kingdom, Sweden and Türkiye. Pat O’Brien's co-authors include Asma Khalil, Peter von Dadelszen, Laura A. Magee, Tim Draycott, Shamez Ladhani, Edward P. Morris, Erkan Kalafat, Kirsty Le Doaré, Shakila Thangaratinam and Russell Viner and has published in prestigious journals such as JAMA, Nature Communications and SHILAP Revista de lepidopterología.

In The Last Decade

Pat O’Brien

41 papers receiving 2.5k citations

Hit Papers

5 papers align trajectories

What are hit papers?

Hit papers significantly outperform the citation benchmark for their cohort. A paper qualifies if it has ≥500 total citations, achieves ≥1.5× the top-1% citation threshold for papers in the same subfield and year (this is the minimum needed to enter the top 1%, not the average within it), or reaches the top citation threshold in at least one of its specific research topics.

Effects of the COVID-19 pandemic on maternal and perinatal outcomes: a systematic review and meta-analysis

2021 631 citations B Chmielewska, Rosemary Townsend et al. The Lancet Global Health profile →
Coronavirus in pregnancy and delivery: rapid review

2020 340 citations Pat O’Brien, Edward P. Morris et al. Ultrasound in Obstetrics and Gynecology profile →
Change in the Incidence of Stillbirth and Preterm Delivery During the COVID-19 Pandemic

2020 317 citations Asma Khalil, Peter von Dadelszen et al. profile →
COVID-19 vaccination during pregnancy: coverage and safety

2021 264 citations Helena Blakeway, Smriti Prasad et al. profile →
SARS-CoV-2 infection in pregnancy: A systematic review and meta-analysis of clinical features and pregnancy outcomes

2020 227 citations Asma Khalil, Erkan Kalafat et al. EClinicalMedicine profile →
Systematic review and meta-analysis of the effectiveness and perinatal outcomes of COVID-19 vaccination in pregnancy

2022 166 citations Smriti Prasad, Erkan Kalafat et al. Nature Communications profile →

Peers — A (Enhanced Table)

Peers by citation overlap · career bar shows stage (early→late) cites · hero ref

Name	h						Papers	Cites
Pat O’Brien United Kingdom	17	2.0k	1.2k	1.0k	330	280	43	2.6k
Rosemary Townsend United Kingdom	18	1.3k 0.6×	1.1k 0.9×	521 0.5×	112 0.3×	104 0.4×	48	1.8k
Léo Pomar Switzerland	18	886 0.4×	453 0.4×	813 0.8×	253 0.8×	206 0.7×	57	2.3k
Juanjuan Guo China	8	1.8k 0.9×	613 0.5×	724 0.7×	482 1.5×	72 0.3×	20	2.7k
Maria Laura Costa Brazil	29	1.7k 0.8×	1.8k 1.6×	741 0.7×	58 0.2×	54 0.2×	154	2.9k
Tara C. Jatlaoui United States	22	770 0.4×	924 0.8×	1.7k 1.7×	41 0.1×	232 0.8×	42	2.5k
Guillaume Favre Switzerland	14	656 0.3×	260 0.2×	313 0.3×	255 0.8×	132 0.5×	34	1.6k
Élie Azria France	27	1000 0.5×	1.1k 0.9×	582 0.6×	40 0.1×	57 0.2×	162	2.4k
Sharon Cameron United Kingdom	32	1.5k 0.7×	1.4k 1.2×	2.4k 2.4×	82 0.2×	42 0.1×	186	3.5k
Li Min Lim Singapore	7	730 0.4×	291 0.3×	357 0.4×	133 0.4×	51 0.2×	14	1.1k
Leila Katz Brazil	20	1.0k 0.5×	897 0.8×	460 0.5×	88 0.3×	42 0.1×	104	1.6k

Countries citing papers authored by Pat O’Brien

Since Specialization

Citations

This map shows the geographic impact of Pat O’Brien's research. It shows the number of citations coming from papers published by authors working in each country. You can also color the map by specialization and compare the number of citations received by Pat O’Brien with the expected number of citations based on a country's size and research output (numbers larger than one mean the country cites Pat O’Brien more than expected).

Fields of papers citing papers by Pat O’Brien

Since Specialization

Physical SciencesHealth SciencesLife SciencesSocial Sciences

This network shows the impact of papers produced by Pat O’Brien. Nodes represent research fields, and links connect fields that are likely to share authors. Colored nodes show fields that tend to cite the papers produced by Pat O’Brien. The network helps show where Pat O’Brien may publish in the future.

Co-authorship network of co-authors of Pat O’Brien

This figure shows the co-authorship network connecting the top 25 collaborators of Pat O’Brien. A scholar is included among the top collaborators of Pat O’Brien based on the total number of citations received by their joint publications. Widths of edges represent the number of papers authors have co-authored together. Node borders signify the number of papers an author published with Pat O’Brien. Pat O’Brien is excluded from the visualization to improve readability, since they are connected to all nodes in the network.

All Works

Sort: Min cites: Since: Top N: Style:

20 of 20 papers shown

Kua, Justin, Pervez Sultan, Brendan Carvalho, et al.. (2025). Snapshot of Obstetric National Audit and Research Project (SONAR1): aprotocol for an international observational cohort study. BMJ Open. 15(6). e103525–e103525.

Engjom, Hilde, Rema Ramakrishnan, Nicola Vousden, et al.. (2024). Perinatal outcomes after admission with COVID-19 in pregnancy: a UK national cohort study. Nature Communications. 15(1). 3234–3234. 8 indexed citations

Khalil, Asma, Athina Samara, Pat O’Brien, & Shamez Ladhani. (2023). Listeria outbreaks cause maternal and perinatal mortality and morbidity: we must do better. The Lancet Microbe. 4(4). e206–e207. 3 indexed citations

Khalil, Asma, Athina Samara, Pat O’Brien, & Shamez Ladhani. (2023). Treatment and prevention of mpox in pregnant people and young children. The Lancet Infectious Diseases. 23(4). 396–397. 9 indexed citations

Khalil, Asma, Athina Samara, Pat O’Brien, & Shamez Ladhani. (2023). Do not forget pregnant and post-partum women during group A streptococcal disease outbreaks. The Lancet Microbe. 4(6). e382–e383. 2 indexed citations

Khalil, Asma, Athina Samara, Pat O’Brien, et al.. (2022). Monkeypox and pregnancy: what do obstetricians need to know?. Ultrasound in Obstetrics and Gynecology. 60(1). 22–27. 31 indexed citations

Prasad, Smriti, Erkan Kalafat, Helena Blakeway, et al.. (2022). Systematic review and meta-analysis of the effectiveness and perinatal outcomes of COVID-19 vaccination in pregnancy. Nature Communications. 13(1). 2414–2414. 166 indexed citations breakdown →

Khalil, Asma, Athina Samara, Pat O’Brien, & Shamez Ladhani. (2022). Monkeypox in children: Update on the current outbreak and need for better reporting. The Lancet Regional Health - Europe. 22. 100521–100521. 5 indexed citations

Khalil, Asma, Athina Samara, Pat O’Brien, & Shamez Ladhani. (2022). Call for a unified approach to Monkeypox infection in pregnancy: Lessons from the COVID-19 pandemic. Nature Communications. 13(1). 5038–5038. 12 indexed citations

10.

Chmielewska, B, Rosemary Townsend, Erkan Kalafat, et al.. (2021). Effects of the COVID-19 pandemic on maternal and perinatal outcomes: a systematic review and meta-analysis. The Lancet Global Health. 9(6). e759–e772. 631 indexed citations breakdown →

11.

Townsend, Rosemary, B Chmielewska, Erkan Kalafat, et al.. (2021). Global changes in maternity care provision during the COVID-19 pandemic: A systematic review and meta-analysis. EClinicalMedicine. 37. 100947–100947. 115 indexed citations

12.

Khalil, Asma, Erkan Kalafat, Can Benlioğlu, et al.. (2020). SARS-CoV-2 infection in pregnancy: A systematic review and meta-analysis of clinical features and pregnancy outcomes. EClinicalMedicine. 25. 100446–100446. 227 indexed citations breakdown →

13.

Khalil, Asma, et al.. (2020). COVID-19 screening of health-care workers in a London maternity hospital. The Lancet Infectious Diseases. 21(1). 23–24. 34 indexed citations

14.

O’Brien, Pat, et al.. (2015). Prenatal diagnosis and obstetric management. Seminars in Pediatric Surgery. 24(5). 203–206. 7 indexed citations

15.

O’Brien, Pat, et al.. (2008). Pregnancy and multiple sclerosis. Journal of Neurology Neurosurgery & Psychiatry. 79(12). 1308–1311. 31 indexed citations

16.

O’Brien, Pat, et al.. (2005). Smart card product development in an internet-based CRM environment. 56. 1 indexed citations

17.

El‐Refaey, Hazem, et al.. (2000). The misoprostol third stage of labour study: a randomised controlled comparison between orally administered misoprostol and standard management. BJOG An International Journal of Obstetrics & Gynaecology. 107(9). 1104–1110. 65 indexed citations

18.

O’Brien, Pat, et al.. (1997). A comparison between the pregnancy outcome of women with gestation diabetes treated with glibenclamide and those treated with insulin.. PubMed. 52(4). 377–81. 15 indexed citations

19.

Okonofua, Friday, et al.. (1991). Evaluation of the roll over test as predictor of gestational hypertension in African women. International Journal of Gynecology & Obstetrics. 35(1). 37–40. 2 indexed citations

20.

Baboonian, C., J. E. Grundy, Pat O’Brien, & Paul Griffiths. (1989). Responses to mitogenic stimulation of lymphocytes taken during and after pregnancy. FEMS Microbiology Letters. 47(4). 199–204. 3 indexed citations

Rankless uses publication and citation data sourced from OpenAlex, an open and comprehensive bibliographic database. While OpenAlex provides broad and valuable coverage of the global research landscape, it—like all bibliographic datasets—has inherent limitations. These include incomplete records, variations in author disambiguation, differences in journal indexing, and delays in data updates. As a result, some metrics and network relationships displayed in Rankless may not fully capture the entirety of a scholar's output or impact.

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