Safe Breathing Techniques During Pregnancy: What Helps, What to Avoid, and Why

Pregnancy produces some of the most significant physiological changes the human body undergoes at any point in life — and several of those changes directly affect how breathing feels and how breathing techniques should be adapted. The growing uterus progressively compresses the diaphragm, reducing lung capacity. Blood volume increases by 40 to 50 percent, increasing the cardiovascular demand on each breath. Progesterone levels rise dramatically and directly stimulate the respiratory centre in the brainstem, causing many pregnant women to feel naturally short of breath even at rest.

Understanding these changes is the starting point for understanding which breathing techniques are safe and beneficial during pregnancy, and which carry risks that do not exist in the non-pregnant state. This guide is organised by trimester because the relevant physiological changes and safety considerations evolve significantly across the three stages of pregnancy.

Important note: Always inform your obstetrician or midwife before beginning any new breathing practice during pregnancy. The guidance in this article is general wellness information, not medical advice, and individual circumstances vary significantly.

What changes in breathing during pregnancy

The most clinically significant change is the progressive upward displacement of the diaphragm by the growing uterus — reaching approximately 4 centimetres of upward displacement by the third trimester. This reduces functional residual capacity (the amount of air remaining in the lungs after a normal exhale) and can make deep diaphragmatic breathing feel more effortful than usual, particularly in the third trimester when the displacement is greatest.

Simultaneously, progesterone — the hormone that maintains the pregnancy — acts directly on the brainstem's respiratory control centre to increase breathing drive. This produces a 40 to 50 percent increase in tidal volume (the amount of air moved with each breath) and a mild respiratory alkalosis — a slight increase in blood pH due to the enhanced exhalation of carbon dioxide. This is physiologically normal and adaptive during pregnancy, but it means that breathing techniques which further lower carbon dioxide (rapid breathing or forceful exhalations) can exacerbate the alkalosis and produce lightheadedness, tingling in the extremities, or fetal distress in severe cases.

The absolute contraindications during pregnancy

The following techniques should be completely avoided throughout pregnancy:

Kapalabhati: The rapid forceful abdominal contractions of Kapalabhati generate significant intra-abdominal pressure with each exhalation. During pregnancy, this pressure is transmitted directly to the uterus. Beyond the mechanical concern, the rapid breathing produces hypocapnia (excessive CO₂ exhalation) which causes vasoconstriction — including in the uterine circulation — potentially reducing blood flow to the placenta. Kapalabhati is contraindicated in all trimesters.

Bhastrika (bellows breathing): Similar to Kapalabhati in mechanism and contraindication. The forceful rapid breathing is not appropriate during pregnancy.

Breath holds (kumbhaka) beyond a brief pause: Breath retention reduces oxygen delivery to the fetus. Extended breath holds — as found in the standard versions of box breathing and some advanced pranayama — should be modified by removing all holds. Brief natural pauses at the end of the exhale (less than two seconds) are generally acceptable, but deliberate extended holds are not recommended.

Prolonged lying flat on the back (supine) after 20 weeks: Not specific to breathing techniques, but relevant because many relaxation and breathing practices are done lying down. After 20 weeks, the weight of the uterus can compress the inferior vena cava when lying flat, reducing blood return to the heart and potentially causing lightheadedness, nausea, and reduced fetal blood flow. Practise breathing techniques in a side-lying position (left side preferred) or seated after 20 weeks.

First trimester (weeks 1 to 12): establishing the foundation

The first trimester is the period of most rapid fetal development and the period when nausea, fatigue, and anxiety about the pregnancy are most intense. Breathing techniques that address these symptoms safely can make a significant difference to quality of life during what is often the most difficult trimester experientially despite being the least externally visible.

Diaphragmatic breathing: The foundational technique and the safest. Practised seated or lying on the left side, belly breathing calms the nervous system, reduces nausea in many women (the slow, rhythmic movement of the diaphragm has a direct effect on gastric motility), and begins training the respiratory efficiency that will be increasingly valuable as the pregnancy progresses. Ten minutes daily is the recommended starting point.

Modified Anulom Vilom (without holds): Alternate nostril breathing without any breath retention is safe in the first trimester and produces the same autonomic balancing benefits as in the non-pregnant state. The alternating nostril pattern is particularly valuable for pregnancy-related anxiety — common in the first trimester as women process the reality and implications of the pregnancy. Use the ratio 4 inhale : 8 exhale, with no holds at either end.

Second trimester (weeks 13 to 27): the most comfortable period for practice

The second trimester is generally the best period for establishing a more substantial breathing practice. Nausea has typically resolved, energy is improved, and the uterus has not yet grown large enough to significantly restrict the diaphragm. This is the trimester in which the benefits of regular breathing practice — reduced anxiety, improved sleep, lower blood pressure — are most accessible.

Ujjayi breathing (ocean breath): A gentle pranayama technique involving a slight constriction of the glottis (back of the throat) that produces a soft, ocean-like sound with each breath. Ujjayi naturally slows the breath to approximately 4 to 6 breaths per minute, creating coherent breathing-range heart rate variability benefits. It is also the primary breathing technique used during active labour in many natural birth traditions — learning and practising it during the second trimester means it is available as a trained response during the intense demands of labour. No breath holds are involved; it is simply a textured slow breath.

Bhramari (humming bee breath): Safe and particularly valuable during the second trimester. The vagal stimulation and nitric oxide release from Bhramari's humming exhalation are beneficial for both maternal cardiovascular regulation and, interestingly, for fetal awareness — fetuses from approximately 18 to 20 weeks can hear sounds from outside the uterus, and the gentle vibration of Bhramari is one of the earliest ways some mothers begin communicating with their developing baby. Do not use the ear-closing mudra (Shanmukhi) if it produces any sense of pressure; simply hum with hands resting on knees.

Third trimester (weeks 28 to 40): preparing for labour

The third trimester presents the greatest physiological challenge for breathing practice — the diaphragm is significantly compressed, capacity is reduced, and many positions become uncomfortable. However, it is also the trimester where breathing techniques have the most direct application to the immediate upcoming event: labour and delivery.

Labour breathing preparation: Research consistently shows that women who have practised specific breathing patterns during pregnancy access them more effectively during labour — when pain, intensity, and physiological demand make learning new skills impossible. The two most evidence-supported labour breathing techniques are: (1) slow diaphragmatic breathing at approximately 6 to 8 breaths per minute during contractions — reducing pain perception by activating the parasympathetic system and reducing the cortisol response to pain; and (2) the physiological sigh (double inhale followed by long exhale) between contractions, which produces rapid recovery and reduces accumulated tension between contractions.

Positioning: In the third trimester, all lying-down practices should be done on the left side with a pillow between the knees. Seated upright on a chair, birthing ball, or firm cushion is generally the most comfortable and physiologically optimal position. The open chest position available on a birthing ball — leaning slightly forward with hands on knees — maximises available respiratory capacity in the third trimester by reducing diaphragmatic restriction.

Postpartum breathing practice

The immediate postpartum period — particularly the first six weeks — involves significant physiological recovery regardless of delivery method. The diaphragm returns to its pre-pregnancy position, blood volume normalises, and the respiratory alkalosis of pregnancy resolves. Most breathing techniques can be resumed fully after the six-week postnatal check, though women who delivered by caesarean section should avoid any abdominal-activation techniques (including Kapalabhati) until cleared by their surgeon.

Postpartum anxiety and mood disturbances affect a significant proportion of new mothers — estimates suggest 15 to 20 percent experience clinically significant postpartum anxiety or depression. Regular breathing practice, particularly Anulom Vilom and slow diaphragmatic breathing, during the postpartum period supports the physiological regulation that underpins emotional stability during this demanding transition. If you are experiencing significant mood symptoms postpartum, please speak with your healthcare provider — breathing techniques are a valuable complement to professional support, not a substitute for it.