Bumpology: Just how painful is this going to be?
来源：未知 作者：明壕恹 时间：2019-03-01 10:08:01
By Linda Geddes Days to go: 27 Waist size: 103 centimetres (40.5 inches) With just four weeks to go until my due date, my thoughts are turning to the birth of our daughter, and more specifically just how much giving birth is going to hurt. Anecdotally, people say that once you hold your baby in your arms you forget all about the pain you have just endured. This seems unlikely, and I’ve struggled to find any evidence that childbirth induces some kind of immediate pain-related amnesia in women – but please feel free to correct me if I am wrong. It does seem, though, that the memory of labour pain fades with time – at least in women who had a positive experience of childbirth. Past studies have suggested that women who remember childbirth as a negative experience at two months after the birth have fewer subsequent children and take longer to have their next child than women who remember it as a positive experience. To investigate further, Ulla Waldenström and Erica Schytt at the Karolinska Institute in Stockholm, Sweden, asked 1383 women to rate their experience of labour pain on a seven-point scale at two months, one year and five years after the birth. “Women who had a very positive or positive memory of childbirth at two months changed their assessment of labour pain over time,” says Waldenström. “They remembered pain as less and less intense.” However, women who said childbirth was a negative or very negative experience did not change their assessment of labour pain as time passed. Whether women rated their childbirth experience as positive or negative didn’t seem particularly linked to the level of pain they remembered at two months. Instead it could be linked to other factors such as the level of support they received from their caregivers. Besides being nice to the midwives, and mentally preparing myself for labour, I’m not sure how easy it will be to guarantee that my experience of childbirth will be a happy one. But I have also been comforting myself with a study that suggests that women experience a rise in pain threshold during labour. That is perhaps just as well, given what my body is going to have to do. Iris Ohel and her colleagues at Soroka University Medical Center in Beer Sheva, Israel, used a tool called a dolorimeter to exert pressure at various tender points around the body, and measure at what pressure it became painful. They assessed 40 women at between 37 and 42 weeks of pregnancy, during active labour and after birth, and found a significant increase in pain threshold during the active phase of childbirth. The increase in pain threshold was also greater in women who had reached term – beyond 40 weeks of pregnancy. “We can only speculate that this is an expression of a maturation process peaking at term and leading the [woman] to an optimal status for delivery,” Ohel says. Other studies have suggested that labour can inhibit pain by activating inhibitory neurons in the brain. Priti Bajaj at Aalborg University in Denmark and her colleagues found that women’s pain threshold seemed to increase during the third trimester of pregnancy – and that the intensity of labour pain was lower in women who had recently experienced pelvic pain. It’s also possible that the natural opiates called endorphins, which are released during labour, may be dampening pain. Finally, other studies have suggested that a lack of family support can reduce the pain threshold, while giving birth during the morning seems to diminish women’s perception of pain. So perhaps the best strategy is to get a good night’s rest, a big hug from my husband, and hope for the best. Journal references: “A longitudinal study of women’s memory of labour pain” by Ulla Waldenström and Erica Schytt, British Journal of Obstetrics and Gynaecology, DOI: 10.1111/j.1471-0528.2008.02020.x “A rise in pain threshold during labor: A prospective clinical trial” by Iris Ohel, Pain, DOI: 10.1016/j.pain.2007.05.007 “Antenatal women with or without pelvic pain can be characterized by generalized or segmental hypoalgesia in late pregnancy” by Priti Bajaj and others, The Journal of Pain, DOI: 10.1054/jpai.2002.128065 Read previous Bumpology columns: Men go through pregnancy too, What you can teach a fetus, Fed up of the booze and cigs police, Why can’t my baby sleep when I do?, Choosing the sex of your child, Pregnant at the cheese and wine party, Is my baby making me forgetful?, What does an amniotic cocktail taste like?, My fetus is smarter than an earthworm, Ultrasound reveals breastfeeding mechanics. More on these topics: