Pregnant women getting the Pfizer/BioNTech vaccine against Covid-19 should be given it between the 14th and 33rd weeks of their pregnancy, Irish medical experts have advised.
"If the second dose is not given by 33 completed weeks, it should be delayed until after delivery," according to information from the Institute of Obstetricians and Gynaecologists and the National Immunisation Advisory Committee.
“This will avoid confusion that may arise if a fever develops following the second dose.”
Dr Cliona Murphy, chair of the institute, said it was important that women seek trusted information about the vaccines and assess their risks with regards to Covid-19 and the jab with their healthcare providers.
Pregnant women are at a similar risk of contracting Covid-19 as the rest of the female population, the two groups say. Most who become infected will experience only mild to moderate symptoms and the risk of passing the virus on to the baby is low.
However, pregnant women showing symptoms may be more likely to be admitted to hospital, to need care in an ICU, and to die when compared with other women.
There may be an increased rate of preterm birth and stillbirth among pregnant patients.
"We have seen a higher rate of hospitalisation and high dependency care in Ireland but thankfully no maternal death from Covid in 2020," the information says.
Not excluded
Pregnant women are “not excluded” from getting the Pfizer/BioNTech vaccine, known as Comirnaty, the obstetricians say.
It is recommended that pregnant women who are at high risk of severe Covid-19 and pregnant healthcare workers talk to their obstetrics care provider about having the vaccine.
“They should discuss their risk of getting Covid-19 in light of their particular circumstances. Based on this they can consider getting the vaccine balancing the small unknown risks related to the vaccine against the serious risks associated with Covid-19.”
For pregnant women, vaccines will reduce the chance of becoming severely unwell. They may also reduce the chance of pregnancy complications, such as preterm birth, which are associated with severe Covid-19 illness.
A three-week interval is recommended between the two doses of Comirnaty. The information says pregnant women should get the first at or after 14 weeks and the second by 33 weeks.
Common side effects include fatigue, headache, sore arm, fever and muscle or joint pains, and are more common after the second dose.
Fever after vaccines usually resolves within two days without treatment but can be managed with paracetamol. Pregnant women should not take ibuprofen and should seek medical advice if feeling unwell after a getting a vaccine to rule out other reasons.
Safety data
There is limited data on the safety of Covid-19 vaccines in pregnancy and breastfeeding but they are not expected to have any effect on the foetus, according to the information.
Breastfeeding is advised for mothers who got the vaccine while pregnant and may give some protection to the baby. Currently breastfeeding mothers can also get the vaccine.
There is no need to leave any interval before getting pregnant again, or to start fertility treatment and there is no evidence the vaccine affects fertility, according to the advice.
“However, you may wish to defer it until you have completed the full course (of fertility treatment), in view of the risk of side effects such as fever in the 48 hours following the vaccine, especially the second dose.”
The information refers specifically to the Pfizer/BioNTech vaccine but further advice will be published as more vaccines become available.
