Tamiflu, placental positioning, pitocin and SSRIs

Welcome to the weekly ZIP - your Zenith Informed Pregnancy!

Read on for a quick zip through 3 of the week’s most popular pregnancy questions, and the evidence behind them. Plus - bonus content on the latest & greatest in the world of pregnancy research. 

This week's top pregnancy questions:

1️⃣ Can I use Tamiflu?

2️⃣ I have an anterior placenta - what does that mean, and can it change?

3️⃣ Risks and benefits of pitocin for labor induction?

Can I use Tamiflu?

Unfortunately, despite the best efforts of many to stay healthy and prepare for flu season with the vaccine, influenza cases are on the rise in many states - so what can moms do if they end up with the flu? “Is Tamiflu safe” topped this week’s most popular questions, so here’s what the data shows. 

📚The tl;dr from the evidence:  Multiple large studies have demonstrated that Tamiflu does not increase the risk of major adverse outcomes (like miscarriage, birth defects, preterm birth, or low birth weight). In fact, guidance from major health organizations like ACOG states that doctors should get pregnant patients on the treatment as soon as symptoms begin, ideally within 48 hours. Treating the flu is especially important during pregnancy, given that pregnant women are more likely than non-pregnant people to experience flu-related severe illness, complications, or hospitalization – all of which carry more risk than Tamiflu based on the data. 

Tamiflu, or oseltamivir, is an antiviral medication used to keep the flu virus from multiplying and reduce symptoms – it’s not a substitute for the flu shot in terms of prevention, but can be used at the earliest onset of symptoms. Other antivirals are also considered safe during pregnancy based on the research, but oseltamivir has the most/best data. 

Studies have also shown that Tamiflu is safe to use while breastfeeding, as the amount that passes through breastmilk to the infant is very low – and infants as young as 2 weeks may even be prescribed Tamiflu directly if the need arises, at much higher doses than would pass through breastmilk.  

👀 Read Penny’s full summary of the evidence for more on tamiflu and influenza

I have an anterior placenta - what does that mean, and can it change?

Hearing the term “anterior placenta” at a second trimester ultrasound can spark a lot of confusion and questions - but know that you’re not alone, as studies estimate up to nearly 50% of women have an anterior placenta! Read on for what this placental positioning means and how it might change over time. 

📚The tl;dr from the evidence:  An anterior placenta just means that the placenta is attached to the front wall of your uterus, rather than the back wall (otherwise known as a posterior placenta). The placement of the placenta is due to normal variance, and an anterior placenta has no impact on the health of your baby – it still functions exactly the same way, providing oxygen and nutrients.

Since an anterior placenta sits between your belly and the baby, it may be harder to feel kicks or movement, particularly earlier on in pregnancy. This means that you might not feel the baby move for the first time until 20 weeks or after. 

As the uterus expands and grows normally as pregnancy progresses, it’s common for the placenta to shift higher, or appear to “move up”. This may make it easier to feel movement, but otherwise doesn’t generally affect your pregnancy or labor unless your placenta was low-lying initially (which refers to its proximity to the cervix, rather than front/back positioning). Moving up is common and good news for an anterior low-lying placenta, as complications like placenta previa (where the placenta covers the cervix) become less likely. 

👀 Read Penny’s full summary of the evidence for more on placental positioning

Risks and benefits of pitocin for labor induction

Pitocin (a synthetic form of the hormone oxytocin, the hormone that stimulates uterine contractions) is one of the most common interventions used to start or speed up labor. And like most induction-related topics, it comes with plenty of opinions, solicited or otherwise! Here’s what we know about pros and cons from the research, so you can make an informed decision aligned with your preferences and goals. 

📚The tl;dr from the evidence:  Pitocin can be very beneficial and effective in starting labor when there is a medical reason for induction – e.g. when there might be health risks to mom & baby if pregnancy continues (going past 41-42 weeks, diabetes, high blood pressure, infection, or the like). Studies show that pitocin is effective in inducing and/or speeding up labor, which can help lower these risks. Practically speaking, it can also allow for more predictability on delivery timing. 

One risk with pitocin is that contractions may be more intense - more frequent, stronger, or painful - than naturally occurring contractions. It can cause what’s called “uterine hyperstimulation”, which is not common (occurring in ~1-5% of inductions) but means that contractions are too strong or close together, increasing the risk of fetal distress. Pitocin is also associated with an increase in the likelihood of rare complications like uterine rupture or heavy bleeding, which occur infrequently but are serious if they do occur.  

The presence of these risks can also lead to several knock-on effects that affect moms’ preferences: for example, the potential risks increase the need for continuous fetal monitoring, which may in turn limit movement and laboring positions. Due to the higher intensity of contractions, pitocin is also associated with higher rates of pain management interventions like an epidural. Considering these downstream effects is important as you make your full birth plan and preferences – additional interventions aren't a guarantee (many moms have positive & empowering experiences with or without additional interventions!), but always are a possibility.

It’s always appropriate to ask why pitocin is being suggested, what alternatives may exist, and what to expect during and following the induction – it can be a helpful and safe tool in both elective and medically necessary inductions, but like any other intervention, needs your informed consent to proceed.  

👀 Read Penny’s full summary of the evidence for more on pitocin inductions

🤓 Zenith's top read of the week

Bonus: what the Zenith team found interesting this week. Think cool pregnancy research or recently published studies, news in pregnancy health and policy, and more!

Untangling the Risks of Antidepressants in Pregnancy (Krista Huybrechts, Ph.D. et al, NEJM) -  This past July, a controversial FDA panel focused on the use of SSRIs (antidepressant medications) during pregnancy, and casted some doubt on their safety. While many maternal mental health experts, including ACOG, immediately and publicly disagreed with these doubts, a fog of uncertainty has continued to plague moms who are newly pregnant or trying to conceive – how to make sense of all of the different headlines and information and ultimately make a decision that's best for both their baby and themselves?

This new perspective piece, published a few weeks ago in the prestigious New England Journal of Medicine by leading researchers from Harvard, ultimately argues that there should be less controversy about this topic. The piece explores why the best-designed studies and observational data we have available today suggests that there is less risk than the panel indicated, and it’s great to see researchers breaking down the actual data and bringing clarity to a nuanced topic. 

Key excerpt:

“Despite ongoing controversy, data from studies explicitly addressing confounding by indication suggest that SSRI use during pregnancy carries little or no risk for the most serious adverse outcomes."