Medication not uncommonly used in women of reproductive age

Note: This list is not exhaustive.

Reliable and accurate information is freely available to women and their partners though the UK Teratology Information Service (UKTIS) on line resource ‘bumps’
Their information leaflets summarise the available scientific information in a way that is understandable to everyone, helping women and their partners make informed decisions in conjunction with their healthcare provider about the use of a medicine in pregnancy.
It should be stressed to patients that the risks from drugs identified as teratogenic can be small but it is important to seek preconception advice since some effects can be very serious and it is likely alternative safer treatments are available.
The ‘bumps’ website also allows all pregnant women to create their own ‘my bumps’ password protected record. The information entered is stored anonymously by the UKTIS and reviewed periodically to help better understand the effects of medicines, lifestyle or illness on fetal developmental.
The following is intended as a guide and is only correct at the time this guidance was updated. UKTIS – Evidence-based safety information about medication, vaccine, chemical and radiological exposures in pregnancy will provide evidence-based information on fetal risk following pharmacological and other potentially toxic pregnancy exposures.

Analgesia

Paracetamol has been used for many years without any obvious harmful effects on the developing baby. For this reason paracetamol is usually recommended as the first choice of pain killer for pregnant women.
Non-steroidal anti-inflammatory drugs (NSAIDs) use in pregnancy has been associated with increased risks of various congenital malformations, including cardiovascular defects and oral clefts, as well as an increased risk of spontaneous abortion. Women using NSAIDs under specialist care should be referred back to their specialist to explore the perceived benefits of continuing/discontinuing treatment, reducing dose or changing medication.

Antibiotics

Penicillins, erythromycin and cephalosporins have no proven harmful effects for the pregnancy or the developing baby.
Antibiotics to be avoided include streptomycin and the tetracycline family. Trimethoprim should be avoided in the 1st trimester.

Anticoagulants

Women on anticoagulants including warfarin should be accessing specialist services prior to conception.
Warfarin exposure in pregnancy should be avoided where ever possible.
Fetal warfarin syndrome (FWS) or warfarin embryopathy is a well recognised complication following warfarin exposure in pregnancy.
The critical period for the development of FWS has not been defined, although data suggests that the risk period covers gestational weeks 6-12.
Exposure to warfarin later in the pregnancy can lead to internal bleeding in the fetus.
Warfarin can also cause bleeding behind the placenta which may reduce fetal growth, placental abruption, and stillbirth.
There is also an increased risk of preterm delivery.
Babies exposed to warfarin in utero are also at increased risk of behavioural or learning problems.
Most women who take warfarin and who are planning a pregnancy, or who have discovered they are pregnant, will be switched to a different anticoagulant. However, for some women (particularly those with mechanical heart values), continued treatment with warfarin may be considered the safer option.

Antiepileptic drugs (AED)

Most AEDs are teratogenic, although the risk is reduced with monotherapy.
Some AEDs are potentially less likely to cause problems, but the risk to the fetus needs to be balanced with the risk of seizures in the mother which puts both the mother and the baby at possible.
Women with seizure disorders should be accessing specialist services prior to conception.

Antifungals for thrush

Most pregnant women with vaginal thrush will be advised to try clotrimazole first. Some studies suggest that miscarriage may be more common following fluconazole use in pregnancy (<21 weeks), and it also been suggested that babies exposed to fluconazole may have a slightly higher chance of having rare heart defects (<13 weeks).
Fluconazole use later in pregnancy would not be able to cause these problems.

Drugs to treat hepatitis C

Current hepatitis C treatment options are unsuitable for use in pregnancy due to concerns over teratogenicity.
In addition women should not conceive for four months after ribavirin treatment ends.
Pregnancy also needs to be avoided for up to seven months following paternal use of ribavirin.
Women (and their partners) need to explore their plans for conception with their specialist.

Drugs used for diabetes

The available data does not show an increased risk of congenital malformations or other adverse pregnancy outcome with insulin and/or metformin use.
Other medicines used for control of blood sugar and other aspects of diabetes such as blood pressure and lipids need discussion with specialists within medical obstetric services.
Women with pre-exisiting diabetes should be accessing specialist services prior to conception.

Drugs used in hypertension

Any women taking an angiotensin-converting enzyme (ACE) inhibitor who is planning a pregnancy should speak to her GP or specialist to discuss the possibility of switching to a different medication before she conceives.
Some women with certain illness may need to take an ACE inhibitor in the first trimester.
Use in the second and third trimester is not generally advised but may occasionally be considered necessary for treatment of some very serious conditions. Second and third trimester use can cause significant problems such as renal tubular aplasia and intra uterine growth retardation.
Current guidelines on diseases for which statins are frequently prescribed recommend that women wishing to become pregnant stop use of statins three months prior to attempting to conceive.

Drugs used in rheumatological conditions and autoimmune diseases

Leflunomide is detectable in plasma up to 2 years after discontinuation of the drug. For this reason the fetus could have in utero exposure to leflunomide up to 2 years after the end of treatment unless a ‘wash out’ process has been used to achieve undetectable plasma levels.
Other drugs need to be avoided for up to twelve months.
Because of the way some of these drugs work they theoretically may also damage sperm.
Women (and their partners) need to explore with their specialist the perceived benefits of continuing/discontinuing treatment, reducing dose, changing medication prior to conception.
Women (and their male partners) on treatment for rheumatological/autoimmune conditions with an accidental pregnancy should seek urgent specialist advice for a careful evaluation of foetal risk and for advice on the appropriate maternal dose of folic acid.

Hayfever treatment

Women should be advised to avoid or limit their exposure to pollen.
If treatment is needed first line would be an antihistamine or corticosteroid nasal or eye drops since the amount of drug that enters the blood stream is very small.
Patients requiring oral antihistamines should seek medical advice since there is more safety information available for some antihistamines compared to others.
Sprays, drops or oral medication containing decongestants should not be used at any stage because they could reduce the blood flow in the placenta.

Herbal medications

Do not assume safety of products labelled as herbal, natural or alternative.

Lithium

It is not known whether it is safe or not to take lithium in pregnancy.
Women need to explore with their mental health specialists the perceived benefits of discontinuing treatment, reducing dose, changing medication against the risk of maternal relapse during pregnancy or post partum to mother and child.
For some women treatment with lithium in pregnancy maybe necessary.

Selective serotonin reuptake inhibitors (SSRI)

Used in the management of anxiety and depression.
Data is conflicting as to whether these are associated with spontaneous abortion, preterm delivery, low birth weight, fetal malformation, and persistent pulmonary hypertension of the newborn and subsequent impairment of neurodevelopement.
Women need to explore with the GP or mental health care specialists the perceived benefits of discontinuing treatment, reducing dose, changing medication against the risk of maternal relapse during pregnancy or post partum to mother and child.
Remaining well is particularly important in pregnancy and while caring for a baby, and for some women treatment with an SSRI in pregnancy may be necessary.

Last reviewed: 30/09/2021

Next review date: 30/09/2025

Author(s): West of Scotland Managed Clinical Network for Sexual Health Clinical Guidelines Group .

Version: 3.1

Approved By: West of Scotland Managed Clinical Network in Sexual Health