How safe is it to take medication during pregnancy?

A telephone helpline for pregnant women closed for good this week, and obstetricians aren’t happy about it.

Motherisk, operated by Toronto’s SickKids Hospital since 1985, provided advice to women on which medications were safe to use in pregnancy, and which weren’t.

The hospital closed it down partly due to a lack of funding, it said in a statement.

Doctors were alarmed by the announcement, saying that many hospitals don’t have specialists in this field, and health care workers also used the helpline as a resource to advise their patients.

“It would be an incredibly important resource to preserve,” said Dr. Jennifer Blake, CEO of the Society of Obstetricians and Gynaecologists of Canada. Some physicians are signing petitions to save the helpline.

Although an estimated nine in 10 women take some kind of medication during pregnancy, obstetrical care providers are often “without adequate information regarding the safety, efficacy and proper doses of many commonly used medications,” according to a recent editorial in the New England Journal of Medicine.

The gaps in knowledge are “huge,” said Dr. Wee Shian Chan, an obstetrical medicine specialist and head of medicine at B.C. Women’s Hospital.

To start with, most clinical drug trials don’t include pregnant women. That means that those women are using medication “in the absence of relevant clinical trial data confirming the potential benefits and harms,” according to a recent book on the subject. Many doctors are trying to change this and get more pregnant women included in drug trials.

And where there is data, said Chan, it often doesn’t go far enough. “We usually focus on gross abnormalities,” she said, things like whether the baby has the correct number of fingers and toes. “What we don’t know about most drugs, which require longer studies, are neurodevelopmental issues.”

So, for example, doctors don’t always know whether the impact of a given medication doesn’t show up until the child is 10 years old, she said.

That doesn’t mean that you should refrain from all medications during pregnancy.

“If you’ve got a medical condition, it’s important that that medical condition be treated — whether it’s mental health or any other kind of health problem,” Blake said.

Tweet This Click to share quote on Twitter: "If you've got a medical condition, it's important that that medical condition be treated — whether it's mental health or any other kind of health problem," Blake said.

“And the medication that you’re on, it may or may not be the ideal one, but if you’ve got a medical problem needing care, it’s not going to go away just because you’re pregnant.”

Some medications — like the acne drug Accutane, for example — are very unsafe to use during pregnancy and might even require that a woman be using effective birth control while she takes them.

But if you have a pre-existing condition and are taking medication to control it, you should talk to your doctor about options, Blake said. “Your family doctor can set that up with an obstetrician who can go through your medication list and give you advice on medications that might be an alternative, a safer option for you.”

In those consultations, Chan said, “We will often have to get an understanding of their underlying chronic condition and the importance of medication to maintain that condition.”

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They will then give some advice. “We base it on our understanding of that medical condition and how it can change during pregnancy. And we anticipate the changes. And then we also base it on our understanding of the safety of medications and the harm of medications at various stages of pregnancy.”

Some medications are dangerous only during a specific trimester, she said, or some medical conditions present a higher risk to the mother only at specific times during her pregnancy. So, doctors might be able to tailor medications to fit a patient’s needs.

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They get their information from studies, patient registries and long-term research conducted by organizations like MotherToBaby, a U.S. group that was partnered with Canada’s Motherisk to disseminate information on medication use. These studies follow women and their children over time to check for problems, Chan said.

Doctors like her will most often recommend medications with a long history of use, she said.

“If you need to be on a medication, the vast majority of medications are safe. And while we may not have a randomized controlled trial, we have plenty of experience to build on,” said Blake.

Some women are comfortable taking medication and some don’t even want to take prenatal vitamins while pregnant, Chan said. Whatever their decision, “Our job is to support women’s choices in pregnancy.”

— With a file from Shallima Maharaj