Pregnancy and COVID-19

Pregnancy and COVID-19

Updated 1 Jun 2020

Author: Dr Andrew Dickson, Occupational Health Physician

Source: Royal College of Obstetricians and Gynaecologists + Royal College of Midwives

Reference document:


Effect on pregnant women: For viral infections in general, changes to the immune system in pregnancy can be associated with more severe symptoms, particularly towards the end of pregnancy. With Covid-19, however pregnant women do not seem to be at higher risk than non-pregnant women of developing complications requiring hospital admission or of dying from the infection. A UK study, however found that the following subsets of pregnant women with Covid-19 infection were more likely to require hospital admission: from a black or other ethnic minority (more than 4 times more likely), existing health condition (1.52 times more likely), aged over 35 (1.35 times more likely), overweight or obese (1.91 times more likely).

Pre-term birth: In other types of coronavirus infection (SARS, MERS), the risks to pregnant women appear to increase in particular during the last trimester of pregnancy. In at least one study, there was an increased risk of preterm birth being indicated for maternal medical reasons after 28 weeks’ gestation. [Note that this relates to other coronavirus infections].

Deep vein thrombosis and pulmonary embolism: Pregnancy is known to be a hypercoagulable state (the mother’s blood clots more easily). Emerging evidence also suggests that individuals admitted to hospital with COVID-19 infection are also hypercoagulable. It, therefore seems likely that infection with COVID-19 will be associated with an increased risk of maternal venous thromboembolism (deep vein thrombosis leading to blood clots in the lung).

Miscarriage: There are currently no data suggesting an increased risk of miscarriage or early pregnancy loss in relation to COVID-19. Case reports from early pregnancy studies with SARS and MERS do not demonstrate a convincing relationship between infection and increased risk of miscarriage or second trimester loss.

Preterm birth: There are case reports of preterm birth in women with COVID-19, but it is unclear whether this was necessary due to the virus. There is at least one report of foetal compromise and prelabour preterm rupture of the membranes associated though it is unclear whether this was necessarily caused by COVID-19 infection.

Can the infection spread to the foetus?  Only two cases have been reported where tests suggest this may have occurred though there may be other explanations. Previous case reports from China reported no evidence of Covid-19 in amniotic fluid, cord blood, neonatal throat swabs, placental swabs, genital fluid or breast milk.

Potential for foetal defects: There is no evidence currently that the virus is teratogenic (causes birth defects).

Infant feeding: Studies to date suggest that Covid-19 virus is not present in breast milk.



Source: Royal College of Obstetricians and Gynaecologists + Royal College of Midwives

Reference document:–health–advice–for–employers-and–pregnant-women.pdf


It is reassuring that there is as yet no robust evidence that pregnant women are more likely to become infected with COVID-19 than other healthy individuals.

It is known from other respiratory infections (e.g. influenza, SARS) that pregnant woman who contract significant respiratory infections in the third trimester (after 28 weeks) are more likely to become seriously unwell. This may also lead to preterm birth of their baby.

Given these additional considerations for pregnant women who become seriously unwell in the later stages of pregnancy, the Government has taken the precautionary approach to include pregnant women in a vulnerable group.

Currently, there is no evidence to suggest that COVID-19 causes problems with a baby’s development or causes miscarriage. With regard to vertical transmission (transmission from woman to baby antenatally or intrapartum), emerging evidence now suggests that vertical transmission is probable. There have been case reports in which this appears likely, but reassuringly the babies were discharged from hospital and were well. In all other reported cases of COVID-19 in babies, infection was found at least 30 hours after birth. The proportion of pregnancies affected by vertical transmission and the significance to the neonate is not yet known. No previous coronavirus has been shown to cause foetal abnormalities and, while COVID-19 is new, there are no reports of an increased incidence of foetal abnormality at routine scans in Asia, indicating this is likely to be the same for the novel coronavirus.

In the UK, significant protections in law for pregnant healthcare workers already exist. These must be followed in relation to COVID-19. Employers should do everything possible to maintain the health of their pregnant employees. The central aspect of this protection is based on risk assessment of each individual pregnant worker’s working environment and the role they play.


Every pregnant healthcare worker should have a risk assessment with their manager, which may involve occupational health. Employers should modify the working environment to limit contact with suspected or confirmed COVID-19 patients to minimise the risk of infection as far as possible. In the light of the limited evidence, pregnant women can only continue to work in direct patient-facing roles if they are under 28 weeks’ gestation and if this follows a risk assessment that recommends they can continue working, subject to modification of the working environment and deployment to suitable alternative duties.


Prior to 28 weeks’ gestation, following a risk assessment with their employer and occupational health, pregnant women should only be supported to continue working if the risk assessment advises that it is safe for them to do so. This means that employers must remove any risks (that are greater in the workplace than to what they would be exposed to outside of the workplace), or else they should be offered suitable alternative work.

Some working environments (e.g. operating theatres, respiratory wards and intensive care/high dependency units) carry a higher risk of exposure to the virus for all healthcare staff, including pregnant women, through the greater number of aerosol-generating procedures (AGPs) performed. Where possible, pregnant women are advised to avoid working in these areas with patients with suspected or confirmed COVID-19 infection.


For pregnant women from 28 weeks’ gestation, or with underlying health conditions such as heart or lung disease at any gestation, a more precautionary approach is advised. Women in this category should be recommended to stay at home.

Healthcare staff in this risk group who have chosen not to follow government advice and attend the workplace must not be deployed in roles where they are working with patients.

Additional factors in pregnancy: Some pregnant women are at very high risk and should ‘shield’. These include pregnant women with significant heart disease (congenital or acquired) or any individuals with specific cancers, severe respiratory conditions (such as cystic fibrosis and severe asthma) and those with rare diseases and inborn errors of metabolism that significantly increase the risk of infections (such as sickle cell disease).

Specific recommendations regarding going to work have been published separately on the RCOG website.

Occupational Health Note: The guidance from RCOG is advisory, and does not distinguish between ‘hazard’ and ‘risk’. It notes for example that some pregnant women should not work in patient-facing roles. It would be better to consider the risk in any role; some patient-facing roles carry no risk because of the control systems in place, while other roles that do not involve patients but may for example involve close contact with others (such as in primary teaching or even travel on public transport) may carry a much higher risk than working in a healthcare setting. Contracting COVID-19 just before or at the time of birth would bring substantial challenges to all involved that are best avoided.


Vulnerability levels

Very high (Red)

Risk of severe illness or death if contracts COVID-19. Read more

High (Orange)

Likely to need hospitalisation if contracts COVID-19, with protracted illness and heavy NHS burden. Read more

Increased/Moderate (Yellow)

Increased risk compared with healthy individual but should recover.

Low/Standard (Green)

No greater risk than healthy individual.