Giving birth

Your guide to pregnancy hormones

Pregnancy, labour and delivery depend on them—how hormones will change your body from before you pee on the stick to well after your baby is born.

By Lauren Ferranti-Ballem
Your guide to pregnancy hormones

Blamed for nausea, gas and unpredictable mood swings, pregnancy hormones have earned a pretty rough reputation. But they’re also responsible for some amazing feats too — from a gloriously shiny mane to that first loving eye lock you’ll share with your new little one. We’ve spoken to two OB/GYNs — Dr. Ahmed Ezzat, president of the Society of Obstetrician and Gynaecologists of Canada and Dr. Elaine Herer from Toronto’s Sunnybrook Hospital — for a rundown on the good, bad and the bizarre of pregnancy hormones.

During pregnancy Even before the moment you test your urine with that ubiquitous stick, hormones are hard at work. The nausea and extreme fatigue common in early pregnancy can be pinned on HcG, says Ezzat, while the physiological changes are due to rising estrogen and progesterone. Combine all of the physical and emotional upheaval, and it’s an intense time, says Herer. “It’s important to remember though that pregnancy is a temporary state. And at the end, you have a beautiful baby in your arms.” So with that happy vision in mind, here are some common hormone-driven changes you may experience.

• The inaccurately named morning sickness; nausea (and sometimes vomiting) can last all day long.

• Erratic emotional highs and lows.

• Cosmetic changes: the surge in blood volume could mean shinier hair and stronger nails that both grow more quickly than usual. Some women also experience acne, brittle nails, skin sensitivity (particularly in the sun) and increased pigmentation on the face, nipples and belly (a vertical line, called the linea negra, appears on some women).

• Constipation and gas, as progesterone slows digestion and relaxes muscles in the gastrointestinal tract.


• Shortness of breath.

• Runny/stuffy/occasionally bloody nose, due to thinning of mucous membranes.

• Increased vaginal secretions.

• Breast and abdominal soreness.

• Headaches and migraines.


After birth If you thought the changes during pregnancy were a lot to deal with, steel yourself. “It can be overwhelming — your body is shifting, healing and recovering, you’re now lactating, likely not sleeping a lot and trying to muddle through the first days of parenthood. Hormones are definitely at play, but there are so many other things going on,” Ezzat says. When you’re bleary eyed and have your spit up-covered T-shirt on backwards, it may help to know that these hormonal blips will pass.

• Immediately after delivery, oxytocin, the love hormone, peaks, helping to form the initial mother-child bond. Oxytocin is also responsible for uterine contractions and can be stimulated by affection from your partner during labour.

• Also during labour, endorphins, the body’s natural painkillers, are produced in the brain.

• Breastfeeding is brought to you by prolactin, a hormone secreted in the pituitary gland that supports the production of milk. Prolactin is also known as the relaxing, nurturing hormone — so don’t be surprised if it becomes habit to doze off as you nurse your newborn.

• With the rise in prolactin, estrogen takes a dive, suppressing ovulation (and likely your period) and resulting in night sweats and hot flashes (similar to menopause, Ezzat says), low libido and corresponding vaginal dryness, which can make sex quite uncomfortable, Herer says.


• Insatiable thirst during breastfeeding is not just related to the need to re-hydrate — the hormonal roller coaster produces in many women a sudden and insatiable urge to drink now, Herer says.

• Baby blues, a mild and short-lived emotional slump, is entirely common in the days after birth, says Ezzat. “The elation is wearing off, you’re sleep-deprived and trying to adjust to a new reality, plus hormones are not cooperating.” The real concern is postpartum depression (PPD), a more intense, longer-lasting crash that is due in part to hormones (the thyroid, for one), and in part to genetics, and is entirely common — it affects about 10 percent of women, according to Ezzat, and requires help and support. Some signs of PPD include unexplained crying, inability to sleep when you have the chance, disinterest in your baby and fantasies of self-harm, harm to your baby and/or suicidal thoughts. It’s crucial to speak to your doctor immediately if this persists beyond a week.

Finding help for postpartum depression

Best Start Resource Centre (800) 397-9567


Canadian Mental Health Association (613) 745-7750

Mood Disorder Society of Canada

Support Groups (604) 255-7999

This article was originally published on November 2010.

This article was originally published on May 07, 2016

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