Most of us, if we have taught yoga for any length of time, have had an errant pregnant student wander into our classes. Whether you are teaching beginner’s yoga, or one-armed levitating bad-ass yoga. If it hasn’t happened to you yet, be assured, it will.

Why? Because on the one hand, first-time pregnant practitioners may not know what classes are appropriate for them  and on the other hand, even serious yoga practitioners have babies. As for the teacher: What follows is usually a tribe of inner yoga teacher voices running around in our heads screaming “What do I do, what do I do…?!”  I’ve been there, truly. It’s what caused me to seek out my first prenatal training in the first place; the desire to better equip myself to teach the occasional prenatal student in the context of my regular classes. What I eventually found was that prenatal yoga would be a passion for me, both teaching students and training teachers alike.

The average 200 hour training does not teach prenatal yoga in depth, if at all, and many teachers are severely lacking in this education. Because of this, I have heard so many well-meaning but erroneous tips, that range from the overly-protective (no inversions, no downdog after the first trimester, no lying on your stomach, no lying on your back, no twists, no no no…) to just plain dangerous: (Bikram even though you’ve never done it before? Inversions even though you’ve never done them either? Sure! ).

So what do you do with that prenatal student?

The first thing to ask is how long and consistently they have been practicing. A beginner is a beginner, pregnant or not. If this is the case, it is not a good time to “advance” your practice. Many people know that pregnancy causes hyper-flexibility in muscles and tissues and as such, may want to use this time to open up those pesky, tight hamstrings. But this is not a good idea. The hormones that open the pelvis in anticipation of birth are not discriminating. They also cause laxity in valves and veins, causing indigestion, heartburn, varicose veins and hemorrhoids. More importantly to the context of yoga, they cause laxity in joints, which, if not taught properly, can cause the yogi to over-extend the connective tissues in the pelvis, knees, shoulders and hips that will lead to long-term injury.

For this reason, it is best to err on the side of caution. The prenatal student, whether beginner or advanced,  should take care not to hyperextend the joints, and for this reason is encouraged, for instance,  to keep a micro-bend in the knees during forward bends, both in flexion and when coming out of them.

Second, even though the prenatal student might be experiencing a higher range of flexibility, it is often the case that the hamstrings are very tight, maybe even more so than usual. The reason for this is two-fold: One: the hamstrings are harder to stretch with a pregnant belly in the way (although there are many excellent variations to accomodate this) and Two: the hamstrings are the muscles that hold one upright. As the belly grows and the weight is thrown forward, the hamstrings have to work extra hard to hold her upright. This is a normal and expected part of pregnancy.

Now what about those other common cautions about lying on your back or front, or inversions or twists? It’s all about the ability of the practitioner. A strong yogi who has been practicing inversions can practice them as long as she feels comfortable in them, right up until birth. The Bikram student can continue as long as she feels okay (although I have some reservations about it as a teacher: the fetus can’t sweat and so can’t cool itself with a rising internal temperature, but it’s best to let the pregnant student be her own voice of authority as much as possible). It’s not, however  a good idea to take up a heated practice if you haven’t already done so. The same goes for lying on the front or back: do it as long as you feel comfortable. The pregnant body has wisdom and does not need the yoga teacher  to tell it when to stop. When a woman feels dizzy on her back, or hot, or light-headed, she will roll over. That is a sign it is time to give up prone positions. For some women it happens early in the pregnancy, for others it may never happen.

Most women will adjust their practices as they need to as they progress through their trimesters. It is handy to outfit yourself with knowledge of modifications for forward bends (using chairs, widening the legs to make room for the belly) and for inversions (using walls and chairs, or other variations if applicable).

Twists such as Ardha Matsyendrasana should be avoided, as they are “deep” twists that cross the belly over the leg and can cause cramping.  So-called “open” twists, and those that leave the belly open but twist the thoracic spine are fine, and encouraged. The belly should always feel open, round and soft. Don’t squish the baby, in other words.

Hip openers are a wonderful way to ease tension in the hips and pelvis. Poses like cat/cow and downward dog can help ease the weight of the baby both in the pelvis and on the pelvic floor. But know how to modify downdog for growing, heavy bodies: with bent knees, blocks under the hands or using the wall.

Traditional “ab” work is ill-advised, as is Boat pose (although boat pose is a hip flexor pose and, not strictly speaking, an abdominal pose) as they can cause hernia. Tightening of the abdominals, as in table balance is encouraged, however, to help keep some tone.

Backbends such as setu bandha sarvangasana (bridge) are okay for all stages of pregnancy, but full bridge/upward bow (urdhva danurasana) should be approached cautiously, as it can cause over-stretching of the abdominals and even risks tearing the placenta.

Students in the first trimester are likely to feel dizzy, tired and nauseous. Watch transitions such as coming up from forward bends and in backbends and encourage them to take child’s pose or other time-outs as often as necessary. All prenatal students should be encouraged to eat before class to keep up their blood sugar, to bring plenty of water and a snack for after class, and to take as many bathroom breaks as necessary.

Students in the second trimester usually feel fabulous. For this reason it is called the “honeymoon” trimester: they feel renewed energy. This is a good time for a stronger, yet careful and mindful practice.

In the third trimester, students will likely begin to feel heavy and tired and need modifications as they approach the due date. But even those cautions being said, there is no one-size-fits-all pregnant student. Some feel great, some love pregnancy, other feel terrible the whole time and hate the whole thing, and every experience in between. There is no one practice for all of them.

It is my opinion that learning how to teach prenatal yoga makes a teacher a better over-all teacher. Why? Because it demands that you have a wide variety of modifications in your yoga-tool belt. It also demands that you teach a wide variety of ability in the context of one class, and that you can teach a class to each individual student with finesse and ease, watching for signs of discomfort without breaking stride.

Above all else, it is best to let the prenatal student be her own voice of authority. Let her tell you how she feels in the poses, what works and what doesn’t, and when it is time to stop. Be compassionate, be caring, and be careful.

Finally, what are your experiences teaching prenatal students? Do you have an interesting story, challenge or success to share?