Book notes for “Expecting Better”, Why the Conventional Pregnancy Wisdom is Wrong and What You Really Need to Know
A very interesting book, it is reassuring to know the actual source behind many recommendations during pregnancy, and a reminder that in many cases it can be important to check for yourself if conventional wisdom applies to your own situation and values, or if conventional wisdom is even based in fact. Often with medical matters we tend to rely entirely on our doctor, but having more knowledge (as long as it is based in fact) can only empower us to make better decisions.
After this book I moved on to some post-pregnancy books. Unfortunately there are none by this author at the moment.
Insights, lessons learnt:
It is worth spending time to research things, and look at the data directly, since often people make descisions for you (see: cosleeping, alcohol in pregnancy) because they believe the outcomes for that recommendation to be better at a population level. If you make decisions for yourself, you can optimise.
Highlight Loc. 343-49 | Added on Monday, February 29, 2016, 10:57 PM The main research on this uses data from the 19th century (it’s old, but the technology hasn’t changed much!). Here is the idea: prior to the modern era, couples would pretty much get down to business right after the wedding and there were limited birth control options. So you can figure out how fertility varies with age by looking at the chance of having children at all for women getting married at different ages. Researchers found that the chance of having any children was very similar for women who got married at any age between 20 and 35. Then it began to decline: women who got married between 35 and 39 were about 90 percent as likely to have a child as those who got married younger than 35; women who got married between 40 and 44 were only about 62 percent as likely; and women who got married between 45 and 49 were only 14 percent as likely.
Highlight Loc. 391-93 | Added on Monday, February 29, 2016, 11:00 PM Obese women have more pregnancy complications, as the graph on the next page illustrates. One example: 23 percent of normal-weight women have a C-section, versus almost 40 percent of obese women. The risk of pre-eclampsia, a serious pregnancy complication, is more than three times as high if you are obese.
Drinking cannot harm baby in first 2 weeks!
Highlight Loc. 631-35 | Added on Wednesday, March 02, 2016, 07:01 AM For the period between fertilisation (around ovulation or a day or two later) and your missed period, your baby is a mass of identical cells. Any of these cells could develop into any part of the baby. If you do something that kills one of these cells (such as heavy drinking or some kind of really bad prescription drug use), another cell can replace it and do exactly the same thing. The resulting baby is unaffected. However, if you kill too many of these cells, the embryo will fail to develop and you will not wind up pregnant at all. It’s an all-or-nothing thing.
Highlight Loc. 645-47 | Added on Wednesday, March 02, 2016, 07:01 AM In the 1920s, doctors identified a hormone, hCG, that is secreted in the urine of pregnant women. A test was developed based on this, but it wasn’t very user-friendly. It required injecting the urine into the ear of a live rabbit that was subsequently killed and dissected. It wasn’t until the 1960s that doctors figured out how to test for this hormone without the rabbit.
Highlight Loc. 664-65 | Added on Wednesday, March 02, 2016, 07:03 AM Some researchers suggest that as many as 50 percent or more of fertilised eggs do not result in pregnancy; of course, not all of these fertilisations are detected even with very sensitive tests.
Highlight Loc. 1309-11 | Added on Saturday, March 05, 2016, 01:34 AM If you are seen at six weeks and things look normal, what is the overall chance that you will have a miscarriage? The data suggests about 11 percent. If you are seen later, say, at eight weeks and things look normal at that point, then the chance of miscarriage is lower, about 6 percent. By the eleventh week, it has dropped to less than 2 percent.
Highlight Loc. 1313-15 | Added on Saturday, March 05, 2016, 01:34 AM A study in England showed that the chance of first-trimester miscarriage was around 4 to 5 percent for first pregnancies or women with a previous successful pregnancy. But for those with a previous miscarriage, it was around 25 percent.
Highlight Loc. 1318-20 | Added on Saturday, March 05, 2016, 01:35 AM A second factor is age. Older women are more likely to miscarry (this is likely related to a higher rate of chromosomal problems). These effects are large. In one study the miscarriage rate was 4.4 percent for women under 20, 6.7 percent for women 20 to 35 and almost 19 percent for women over 35.
Highlight Loc. 1534 | Added on Sunday, March 06, 2016, 08:45 AM Averaging across a few studies, researchers found that a 1 microgram/gram increase in mercury level led to a decrease of 0.7 IQ points.
Highlight Loc. 1547-48 | Added on Sunday, March 06, 2016, 08:46 AM increasing your DHA intake by 1 gram per day would increase your child’s IQ by, on average, 1.3 points.
Highlight Loc. 1558-67 | Added on Sunday, March 06, 2016, 08:48 AM The fish in the top right quadrant are the best: these are fish that are high in omega-3s but low in mercury, such as herring and sardines (small, oily fish) and salmon. Eating more of these fish can be nothing but good. Eighty-five grams of sardines a day would have a huge impact on your omega-3 intake, but virtually no effect on mercury level. Other fish - those on the bottom left - are obviously bad. Take something like orange roughy (not a super common choice, but not totally unknown): not a lot of omega-3s and a whole load of mercury. Sadly, my favourite choice of tinned tuna is in this area, as well. And then there are those in the middle. The fish on the bottom right - tilefish, swordfish, sushi-grade tuna - are ambiguous. Although they are high in mercury, they also have a lot of omega-3s. You make your kid a little less smart with the mercury and a little smarter with the omega-3s. They’re obviously not as good as the herring and sardines, but they’re a lot better than the grouper and the orange roughy. Faced with a choice between tinned tuna and sushi tuna, the sushi-grade tuna is, surprisingly, probably a better choice. It’s a little higher in mercury, but a lot higher in DHA.
Highlight Loc. 1614-18 | Added on Sunday, March 06, 2016, 08:57 AM Almost 90 percent of women report some symptoms of nausea and more than half report some vomiting as well. This tends to peak at around eight or nine weeks of pregnancy and fall off after that. The graph below gives you a sense of how many women report being sick by week of pregnancy. 2 Almost 50 percent of the women in this study reported vomiting at some point in weeks five to eight of pregnancy, but it was less than 15 to 20 percent by seventeen weeks.
Highlight Loc. 1630-34 | Added on Sunday, March 06, 2016, 08:59 AM The average pregnant woman starts to feel bad at around six weeks (that’s two weeks after her missed period). She starts feeling better at around thirteen or fourteen weeks, a couple of weeks into the second trimester. During this time, she may or may not throw up at all. If she does, it will typically be concentrated in just a few days (although those days might be quite bad). If you are throwing up every day for a month, that is unusual: in these studies, only about 5 percent of women report nausea that severe.
Highlight Loc. 1643-44 | Added on Sunday, March 06, 2016, 09:00 AM one study showed that the overall risk of first-trimester miscarriage was 30 percent for women without nausea versus just 8 percent for those who were nauseated.
Highlight Loc. 1877-81 | Added on Sunday, March 06, 2016, 10:04 AM a study in England of about 57,000 pregnancies. This study found that the first trimester screening could detect 91 percent of Down’s syndrome cases. This study also answered my second question. The researchers reported a 6.3 percent false positive rate. This means that for every 100 women tested, about 6 of them were told they were positive but in fact their babies turned out to be perfectly healthy.
Highlight Loc. 1930-31 | Added on Sunday, March 06, 2016, 10:07 AM I was 31. My initial risk was about 1 in 700. If I did this screening, about 89 percent of Down’s syndrome cases would be detected. Taking into account the few false positives, my final risk would go down by about almost a factor of 10, to about 1 in 6,000.
Highlight Loc. 2485-86 | Added on Sunday, March 06, 2016, 01:44 PM The authors collected data from 500 women, about half of whom had a girl and half a boy. The average female heart rate was 151.7, and the average male heart rate was 154.9. These were not significantly different
Highlight Loc. 2638-41 | Added on Sunday, March 06, 2016, 01:58 PM Women who do Kegels regularly are significantly less likely to have urinary leakage. Of course, this is just like any other exercise: it works by building up your muscles. So there is no reason not to start even before you are pregnant, although these studies show you can get the benefits of the exercise even if you start midway through the pregnancy.
Highlight Loc. 2641-43 | Added on Sunday, March 06, 2016, 01:58 PM A review article from 2009 suggests that women who are encouraged to do these exercises are less than half as likely as control women to experience any urinary incontinence during late pregnancy or in the post-natal period. This is especially true for women having their first baby.
Highlight Loc. 2725-26 | Added on Sunday, March 06, 2016, 02:03 PM Most evidence suggests that restrictions on back sleeping are overblown, although one recent study disagrees. Concrete guidance is limited.
Highlight Loc. 2810-11 | Added on Sunday, March 06, 2016, 02:12 PM Although there are no randomised trials in pregnant women, the evidence on the safety of paracetamol is vast, which is why it deserves the Category B ranking.
Highlight Loc. 3026-30 | Added on Sunday, March 06, 2016, 09:49 PM There is a bit of randomised controlled trial evidence on this. In a study of 1,200 women with singleton pregnancies and threatened pre-term labour, about 400 of them were put on bed rest and the other 800 were not. Bed rest was not effective at preventing pre-term birth (7.9 percent of the bed rest group and 8.5 percent of the control group had their babies prematurely). 7 There’s more randomised evidence for multiple gestations and again, there is no evidence that women put on bed rest had fewer pre-term deliveries or better general outcomes.
Highlight Loc. 3253-55 | Added on Thursday, March 10, 2016, 02:24 AM You are most likely to have your baby in your 39th week of pregnancy: close to 30 percent of babies are born in this week. The next most common week is week 38 (18 percent), followed by the 40th week (17 percent). About 70 percent of babies are born before their due date. This includes all births; first births and those that are not induced tend to be a bit later.
Highlight Loc. 3279-82 | Added on Thursday, March 10, 2016, 02:25 AM If you get to your due date without a baby, there is a 60 percent chance you’ll have the baby in the next seven days. If you haven’t had the baby by 41 weeks, there is about a 60 percent chance you’ll go into labour spontaneously. At 42 weeks the vast majority of doctors will induce labour.
Highlight Loc. 3299-3303 | Added on Thursday, March 10, 2016, 02:28 AM The most precise data I could find on this comes from one study in the United Kingdom that measured this effacement by ultrasound at 37 weeks and then recorded the chance of going into labour by the due date. The graph below shows the results. For women who were more than 60 percent effaced (that means shortened about halfway) at 37 weeks, almost all of them (something like 98 percent) went into labour before their due date. On the other hand, for women who were less than 40 percent effaced, almost none of them (less than 10 percent) went into labour before their due date.
Highlight Loc. 3362-67 | Added on Thursday, March 10, 2016, 02:31 AM researchers find that women who are induced with Syntocinon are more likely to use an epidural; increased use of pain relief probably points to increased pain (at least before the epidural was administered!). Secondly, there is both direct and indirect evidence that induction can increase the risk of a C-section. This seems to be most true when Syntocinon is used alone. Of course, C-sections are safe and common, but recovery from them still tends to be harder than recovery from a vaginal delivery.
Highlight Loc. 3623-26 | Added on Thursday, March 10, 2016, 07:36 AM Caesareans are generally safe and they are common (about 25 percent of births in the United Kingdom). But obstetricians generally agree, for good reason, that they are not the preferred mode of delivery. A Caesarean is major abdominal surgery. Recovery varies across women, but is generally slower than after a vaginal delivery.
Highlight Loc. 3649-50 | Added on Thursday, March 10, 2016, 07:38 AM But large randomised studies have shown that vaginal delivery of breech babies is slightly riskier than a planned Caesarean.
Highlight Loc. 3700-3701 | Added on Thursday, March 10, 2016, 08:41 PM The epidural is extremely popular: it was used in about two-thirds of births in the United States in 2008 and in the UK, about 30 percent of women have an epidural.
Highlight Loc. 3734-36 | Added on Thursday, March 10, 2016, 08:44 PM Primary conclusion: from the standpoint of the baby, the epidural mostly doesn’t matter. Babies who are born to mums who have an epidural are no more likely to spend time in the NICU and no more likely to have low APGAR scores (meaning they are not more likely to be “lethargic”, which is one concern that is bandied about).
Highlight Loc. 3756-61 | Added on Thursday, March 10, 2016, 08:49 PM Negative impacts: Greater use of instruments (forceps or vacuum in delivery), greater use of Caesarean for foetal distress, longer pushing time (15 minutes), higher chance of baby facing up at birth, greater use of Syntocinon in labour, greater chance of low maternal blood pressure, less able to walk after labour, greater chance of needing a catheter, increased chance of fever during labour No differences: Overall Caesarean rate, length of dilation period of labour, vomiting during labour, long-term backache
Highlight Loc. 3961-64 | Added on Thursday, March 10, 2016, 10:28 PM An older study, published in 1991, showed similar impacts. Women in this study were randomly assigned to have either a supportive doula or an observer in the room who did not help. Women with a doula were less than half as likely to have an epidural, had shorter labour, were about half as likely to have a Caesarean and were half as likely to have forceps used in delivery.
Highlight Loc. 4014-17 | Added on Thursday, March 10, 2016, 10:34 PM Based on this evidence, both this review and the most commonly used obstetrics textbook suggest that continuous monitoring isn’t necessary or even a very good idea for most women. It seems like what is happening is that doctors overreact to patterns they see in the heart rate when the baby is not actually in distress. It’s almost as if there is too much information. You might imagine that every baby, no matter how well the birth is going, has a few moments when her heart rate dips.
Highlight Loc. 4133-35 | Added on Thursday, March 10, 2016, 10:41 PM Syntocinon after birth: Useful in preventing postnatal haemorrhage. Recommended.