5 • • • Miscarriage FearsRead - Expecting Better: Why the Conventional Pregnancy Wisdom is Wrong and What You Really Need to Know by Emily Oster

5 •   •   • Miscarriage FearsRead more at location 1167

Note: 5@@@@@@@@@@@@@ Edit

8 •   •   • Antenatal Screening and TestingRead more at location 1555

Note: la decisione sui test a cui sottoporsi è soggettiva dipende dall età e dai valori xsonali e dalla curiosità di solito la scelta è tra test nn invasivi e invasivi... di solito si fanno i primi e a seconda dell esito e dei rischi aggiornati si decide sui secondi oggi si offre l amnio alle ultra 35 xchè? xchè il rischio di aborto è inferiore al rischio di down. asurdo: 1 si trascurano i valori 2 con gli screening preliminari il rischio down varia molto Rischio post traslucenza (rischio iniziale, casi individuati e falsi positivi) Rischio aborto nella traslucenzaEdit

Note: 8@@@@@@@@@@@@@ Edit

There is one major medical decision to be made in the first trimester of pregnancy: antenatal screening.Read more at location 1557

Note: PROBLEMA: COSA FARE CON TEST PRENATALI Edit

thinking about these pluses and minuses for you, personally. I’d argue that no two people will think about this decision quite the same way. Which is why even having a “standard” recommendation here makes so little sense to meRead more at location 1565

Note: L ELEMENTO SOGGETTIVO È ENORME Edit

The goal of all antenatal screening and testing is the same: to learn whether your baby has a chromosomal abnormality.Read more at location 1568

Note: LO SCOPO DEL TEST Edit

Human DNA has 23 pairs of chromosomes. The vast majority of chromosomal problems are caused by having three copies of a chromosome rather than the normal amount of just two.Read more at location 1569

Note: IL PROB DEI CROMOSOMI Edit

By far, the most common of these is Down’s syndrome, which is caused by having three copies of chromosome 21.Read more at location 1572

Note: DOWN Edit

The two other common ones are Edward’s syndrome (three copies of chromosome 18) and Patau syndrome (three copies of chromosome 13). These are more severe than Down’s syndrome;Read more at location 1573

Note: ALTRE DUE TARE Edit

The risk to your baby of any of these conditions depends on your age.Read more at location 1575

Note: L ETÀ È FONDAMENTALE Edit

I was 31 when Penelope was born. This put my risk around 1 in 700. This means that of 700 women my age who get pregnant, on average 1 of them will carry a baby with Down’s syndrome.Read more at location 1577

Note: ES 31 ANNI Edit

amniocentesis)Read more at location 1580

Add a note

This test accurately detects Down’s syndrome and the other chromosomal abnormalities, but carries a small risk of miscarriage. Because of the relationship between these problems and maternal age, it was common to offer this test only to women over 35.Read more at location 1581

Note: AMNIO Edit

Note: OVER 35 Edit

Risk of Down’s Syndrome by Age . . . Age Chance of Down’s syndrome 20–24 1 in 1488 25–29 1 in 1118 30–34 1 in 746 35 1 in 374 36 1 in 289 37 1 in 224 38 1 in 173 39 1 in 136 40 1 in 106 41 1 in 82 42 1 in 63 43 1 in 49 44 1 in 38 45 1 in 30 . . . and some comparisons Car accident within next year: 1 in 50 Audited within next year: 1 in 200 Injury with fireworks within next year: 1 in 19,000 Winning Powerball: 1 in 80 millionRead more at location 1583

Note: TAVOLA DEI RISCHI Edit

in the last 20 years doctors have made enormous progress on antenatal screening. This screening uses information from an ultrasound and from a blood test in addition to information about your age to make a more precise guess about the chance that your baby has a chromosomal problem. The advantage to the screening option is that it carries no miscarriage risk. The disadvantage is that it cannot tell you for sure whether your baby is affected.Read more at location 1622

Note: NUOVI ESAMI MENO INVASIVI MA MENO SICURI Edit

Option 1: Do nothing.Read more at location 1627

Add a note

Option 2: Start with the antenatal screening.Read more at location 1629

Add a note

Option 3: Skip right to the invasive testingRead more at location 1631

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the non-invasive testing goes well, what will the remaining risk be?Read more at location 1640

Note: * Edit

I asked my doctor. She had recommended the screening test (the non-invasive option), so I asked a simple form of my question. If that test went well, what would my risk be? I was told it would be “very low”. “How low?” I asked. “One in a thousand? One in ten thousand? One in thirty thousand?” “Yes,” was the response, “something like that.” I am willing to accept that I’m perhaps a little more neurotic about exact numbers than most people, but this seemed extremely vague: 1 in 1,000 and 1 in 30,000 are quite different.Read more at location 1645

Note: IL DOTTORE STA SUL VAGO Edit

I realised that if I wanted an answer to either of these questions I’d have to do some digging on my own.Read more at location 1660

Note: NN RESTA CHE FAR DA SOLI Edit

Spoiler alert: in the end, I felt optimistic about everything. The non-invasive screening tests are really good. After a good result, my remaining risk would probably be something like 1 in 6,000, which, even by my high standards, is very small.Read more at location 1662

Note: SPOILER SU TEST NN INVASIVI CON EZSITFO POSITIVO SU 31ENNE Edit

The invasive testing has also got hugely better over time. The CVS test (clearly the better option) carries only a tiny risk of miscarriage, much lower than the 1 in 200 figure that was suggested.Read more at location 1664

Note: RISCHIO DI ABORTO SU TEEST INVASIVO Edit

Non-invasive Antenatal ScreeningRead more at location 1666

Note: t Edit

try to figure out whether the fruit is ripe by looking at things you can see on the outside. What colour is it? How does it smell? People have all sorts of tricks for doing this.Read more at location 1672

Note: I TEST NN INVASIVI: GIUDICO DA QUEL CHE VEDO Edit

Take the colour. On average, melons that have some green rind are less likely to be ripe.Read more at location 1675

Note: c Edit

In the case of Down’s syndrome, there are three markers the doctor is looking for in the first trimester screen. The most useful of these is a measurement of the amount of fluid behind the baby’s neck (called the nuchal translucency, or NT). Foetuses who have Down’s syndrome are much more likely to have a lot of fluid behind the neck. Doctors also measure two hormones in Mum’s blood (PAPP-A and HCG). Women who are carrying foetuses with Down’s syndrome also tend to have different hormone levels than those whose babies have normal chromosomes.Read more at location 1686

Note: LA MARCA DEL DOWN NELLA TRASLUCENZA Edit

Why use both hormones and the fluid scan rather than just one or the other? Simple: if you have more signals, you can learn more.Read more at location 1694

Note: c Edit

After doing all these measurements, your doctor will tell you a new level of risk. This risk will be based on these new measurements and also on your age. Your old risk was based only on your age,Read more at location 1700

Note: AGGIORNAMENTO DEL RISCHIO Edit

This new risk is a number.Read more at location 1703

Add a note

Based on your age and the blood test and the ultrasound, your foetus has a 1 in 500 (or 1,000 or 10,000) risk of having a chromosomal problem.Read more at location 1704

Note: ESEMPIO Edit

If your final risk is higher than 1 in 250 (say, 1 in 200), you’ll be told that you should undergo more extensive testing.Read more at location 1709

Note: RACCOM UFFICIALI. FARE ALTRI TEST SE I RISCHI SONO SUP A Edit

I needed to know how accurate these tests were at detecting chromosomal problems. If my final risk was above the cut-off and they told me “Everything is great, do nothing!” how confident could I be?Read more at location 1724

Note: QUANTO È AFFIDABILE IL TST Edit

The answer to my first question about detection rates: about 90 percent. That is, doctors can detect 9 out of 10 Down’s syndrome cases using this screening procedure.Read more at location 1729

Note: c Edit

Among the best is 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.Read more at location 1732

Note: LO STUDIO DECISIVO Edit

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.Read more at location 1734

Note: c Edit

detection rates and false positiveRead more at location 1736

Add a note

detection rate: what percentage of Down’s syndrome cases will be identified by this test?Read more at location 1740

Note: CONCETTI. DETECTION E FALSO POSITIVO Edit

false positive (i.e., you are told the screen is positive, but, in fact, your baby is healthy).Read more at location 1741

Note: c Edit

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.** You know, somewhere between the chance of a midwife delivery and the risk of blanket injury, but just a bit more precise.Read more at location 1798

Note: L ESEMPIO DI UNA 31ENNE Edit

Second Trimester ScreeningRead more at location 1802

Note: t Edit

at this point in the pregnancy, most women are not showing and may not have told many people they are expecting. This may lessen the burden of making a difficult choice about continuing the pregnancy.Read more at location 1803

Note: PERCHÈ LE DONNE FANNO TUTTO NEL PRIMO TRIMESTRE Edit

Other ConditionsRead more at location 1813

Note: t Edit

this same screening procedure is also effective at detecting trisomy 18 and trisomy 13 (Edward’s and Patau syndromes, respectively). These conditions are much rarer – trisomy 18 occurs in about 1 out of 5,000 live births and trisomy 13 in 1 out of 10,000 – and both are typically fatal within the first year of life. The risk of these conditions also varies by age.Read more at location 1814

Note: ALTRE PATOLOGIE Edit

The screening test for these diseases works just like described above, only better: detection rates are very good (much better than for Down’s syndrome) and false positives are rare.Read more at location 1818

Note: QUI LO SCREENING È ANCHE MIGLIORE Edit

The Bottom Line: Part 1 • First trimester screening can detect about 90 percent of Down’s syndrome cases. • The success of this screening varies with age, from around 82 percent in women age 20 to almost 98 percent in women over 40. • False positives also vary with age, from 3 percent for someone in her early twenties to 50 percent for someone in her mid-forties.Read more at location 1823

Note: RIASSUNTINO PRIMA PARTE Edit

Invasive Antenatal Testing: CVS and AmniocentesisRead more at location 1827

Note: t Edit

Both of these tests would allow my doctor (or, more accurately, some lab) to actually sequence our daughter’s DNA and would tell us for sure if she was healthy.Read more at location 1830

Note: AMNIOCENTESI E CVS Edit

the doctor extracts from the uterus a sample of the baby’s cells. The two differences are where those cells come from and at what stage of pregnancy the procedure is performed.Read more at location 1833

Note: IL METODO Edit

This procedure is typically performed between sixteen and twenty weeks of pregnancy (doing it much earlier appears to increase the risk of club foot, so is generally avoided).Read more at location 1837

Note: TEMPI CONSIGLIATI Edit

Amniocentesis has been around for decades. CVS is newer – it was introduced in the early 1980s – but has become increasingly popular over the past ten years. In a CVS test, the cells are taken from the placenta. Again, the doctor goes in with a needle, either through the abdomen or through the cervix and grabs a few placenta cells.Read more at location 1839

Note: CVS. NUOVA PROCEDURA Edit

CVS is performed much earlier in the pregnancy, typically between ten and twelve weeks, before the end of the first trimester.Read more at location 1842

Note: TEMPI Edit

accuracy is, of course, the big plus of these tests relative to the screening. On the negative side is the possibility that the tests could cause a miscarriage. In principle, sticking needles into the uterus could certainly carry some danger.Read more at location 1850

Note: PRO E CONTRO Edit

Common numbers are a 1 in 100 risk of miscarriage from CVS and 1 in 200 from amniocentesis.Read more at location 1853

Note: RISCHIO. SENTITO DIRE Edit

two conclusions. Firstly, the CVS test is transparently a better option than amniocentesis. Recent evidence shows that it carries the same risk of miscarriage and it can be done much earlier in pregnancy. Secondly, the risks from either of these procedures are much lower than 1 in 200. They are so low that it’s hard even to put a figure on it, but my best estimate was about 1 in 800.Read more at location 1854

Note: DATI REALI 800 Edit

The 1 in 200 figure is based on a study from the 1970s that considered about 1,000 women who underwent amniocentesis and 1,000 matched controls.Read more at location 1859

Note: DA DOVE VIENE IL 200? STUDI VECCHI E LIMITATI Edit

In the amniocentesis group, 3.5 percent of the women had a miscarriage. In the control group, it was 3.2 percent. This difference was not statistically significant and disappeared completely when corrected for maternal age.Read more at location 1860

Note: ALTRI VIZI: NN SI CONTROLKA CON L ETÀ Edit

a study in the 1980s that did a better job in various ways and suggested a similar risk. But even this study is hard to learn from, in large part because it is old.10 And, in fact, this “old study” problem is also likely responsible for the impression that CVS is riskier than amniocentesis. Old studies are not always useless. Some things do not change much over a period of 30 years. But some things do and the technology for doing these tests is definitely in that category.Read more at location 1863

Note: ALTRO STUDIO SVIANTE Edit

The biggest changes have to do with the use of ultrasound during these procedures. The most significant risk of these tests is that you accidentally hit the foetus with the needle; a related risk is the needle going through the placenta, which can also cause problems.Read more at location 1867

Note: MA COSA È CAMBIATO NEL TEMPI? Edit

Today, doctors typically watch what they are doing the entire time on the ultrasound.Read more at location 1870

Note: c Edit

What was the true risk if 1 in 200 was too high? The simplest way to figure this out is to compare miscarriage rates for women who have CVS to similar women who have no screening. There are very few studies like this. I did find one and it was very reassuring. It compared 5,000 women who had CVS to 5,000 women who did not.14 The authors found miscarriage rates of 3.3 percent for women who had no procedure and 2.7 percent for women who had the CVS.Read more at location 1889

Note: COMPARARE IL TASSO DI ABORT SPONTANEO TRA CVS E NO SCREENING Edit

Of course, there is no reason to think CVS would be protective; what this study demonstrates is that it is plausible that the risk from the procedure is very small, maybe even zero.Read more at location 1893

Note: c Edit

One good one is the FASTER trial.Read more at location 1897

Note: RISCHIO AMNIO. CVS SIMILE Edit

The chance of pregnancy loss before 24 weeks was 0.94 percent in the control (no amniocentesis) group and 1.0 percent in the treatment (amniocentesis) group. This difference is very smallRead more at location 1900

Note: ESITO Edit

Two other recent studies used a similar design, comparing women who had an amniocentesis to similar women who did not and found the same results.Read more at location 1903

Note: CONFERME Edit

we can’t reject the claim that there is no increase in risk from the procedure. If we take the magnitude of their estimates seriously, they suggest a procedure-related risk between 1 in 600 and 1 in 800.16Read more at location 1905

Note: CONCL Edit

The Bottom Line: Part 2 • Miscarriage risks from CVS and amniocentesis are indistinguishable, making the earlier-in-pregnancy CVS test the clear winner. • A reasonable estimate of procedure-related miscarriage risk from CVS is about 1 in 800 but . . . • . . . most studies are not large enough to allow us to reject the claim that there is no increased risk from this procedure.Read more at location 1907

Note: RIASSUNTINO Edit

Decision TimeRead more at location 1912

Note: t Edit

This recommendation assumes that everyone thinks that having a child with a chromosomal problem is exactly as bad as having a miscarriage. That’s the logic under which comparing the probabilities is enough. This cannot be correct; it might not even be correct for the average person and it’s certainly not correct for every person. It seems extremely likely that for some women and families, they would much prefer to have a child with Down’s syndrome than to lose a healthy baby.Read more at location 1923

Note: RACCOMANDAZIONE DI TEST SOPRA I 35. PEECHÈ A QUEL PUNTO LE PROB SONO SIMILI. TRA L ALTRO PROB SBAGLIATE Edit

Let’s say you are 31. With a good result on the non-invasive screen, the baby’s risk of having Down’s syndrome is around 1 in 7,000. The risk of miscarriage from the CVS test is around 1 in 800. What you need to decide for yourself is whether having a baby with Down’s syndrome unexpectedly would be more than eight times worse than having a miscarriage. If yes, then do the CVS. If no, then stick with the non-invasive screen.Read more at location 1934

Note: IL PROBLEMA RIASSUNTO Edit

We ultimately decided I would undergo the non-invasive screening. Yes, there would be some remaining risk, but it would be very small. The testing went well, we stopped there and Penelope was born healthy.Read more at location 1938

Note: LA DECISIONE Edit

Of course, the absolute best of both worlds would be if you could get the baby’s DNA without going anywhere near the baby. Is this possible? It turns out yes. When you are pregnant, some of the baby’s DNA circulates in your bloodstream – this is called “cell-free foetal DNA”. If doctors could separate out the DNA that belongs to the baby from that which belongs to you, they could effectively “see” the baby’s DNA without seeing their cells.Read more at location 1946

Note: IL FURURDO: TEST A RISCHIO ZERO Edit

science moves fast and when Penelope was about 18 months a newly pregnant friend called me up asking about a test called “MaterniT21” that does exactly this procedure.Read more at location 1950

Note: c Edit

Fumo e caffè in gravidanza

Caffeine + TABACCO - Expecting Better: Why the Conventional Pregnancy Wisdom is Wrong and What You Really Need to Know by Emily Oster

Cosa bere in gravidanza? Dopo l’alcol, passiamo al caffè.

Il consiglio dell’ostetrica…

… My obstetrician said some coffee was fine, but I should stick to less than two cups (again, that’s a 235-millilitre cup)…

Assunzione di caffè e aborti spontanei…

… The big concern with caffeine and pregnancy is that it might lead to higher rates of miscarriage…

Il processo biologico attraverso il quale la caffeina puo’ agire sul feto è piuttosto misterioso…

… Caffeine can cross the placenta and it’s not clear how the foetus processes it. In addition, researchers have speculated that caffeine can inhibit foetal development by limiting blood flow to the placenta. This is a case where the biological story on its own is not very compelling; although there is speculation about these effects, they have not been proven…

Studi su gatti e topi: caffè dannoso se in dosi iperabbondanti…

… What has been shown in a well-controlled way is that very high doses of caffeine do cause miscarriage in mice and rats. But these doses are much, much higher than what people consume. In order to produce pregnancy problems in rats, researchers require something like 250 milligrams of caffeine per kilogram per day. Translated to a human of 10 stone, 10 pounds? That’s a bit more than 60 cups of coffee per day.18 I challenge you to even find the time to drink that much!…

Esperimenti randomizzati sono impossibili per questioni etiche :-(

Tutti gli studi sul caffè hanno un problema: come neutralizzare il fattore nausea? Vediamo meglio in cosa consiste e perché è fondamentale…

… Studies of the impact of caffeine on miscarriage have another problem, one that makes caffeine even harder to study than alcohol: nausea. Nausea is an unpleasant part of early pregnancy, one that most women experience. But (more on this later) it’s also a really good sign about the health of the pregnancy. Women who experience nausea in early pregnancy are less likely to miscarry (it is not clear why this is the case; nausea may reflect hormone levels, but that’s just speculation). Why is this a problem?… We know that nausea is a sign of a healthy pregnancy. At the same time, it also causes women to avoid coffee. But this means that women who drink a lot of coffee are probably those who are not experiencing nausea. These women are more likely to miscarry. But you might be wrong to conclude that coffee causes miscarriage;… Researchers try to “adjust” for this – asking women whether they experienced any nausea, for example – but this is hard to do. Nausea isn’t a yes-or-no thing… fully adjusting for this is basically impossible…

Anche con questo vizio di fondo gli studi di qualità ci dicono che dosi moderate non danneggiano il feto…

… Even with this nausea issue, many studies suggest that in moderation there is no strong link between caffeine and miscarriage…

E 4 tazzine al giorno?

Gli studi migliori cercano di tracciare le abitudini della futura mamma fin da prima del concepimento…

… Perhaps my favourite study of this question is a recent one from the University of Maryland published in 2010. The researchers followed a group of women starting when they tried to get pregnant. They collected daily diaries of their diets, including caffeine….

Uno studio del genere non rinviene alcun collegamento… ma il campione è piccolo…

… This study found no relationship between caffeine and miscarriage. The big drawback, however, is the sample size: with data on only 66 pregnant women means this study is suggestive but not conclusive…

Studi simili con campioni più ampi…

… Consider one covering about 2,400 women published in the journal Epidemiology in 2008.20 Women enrolled in the study either while they were trying to get pregnant or at their first antenatal check-up. Information on coffee consumption was collected at 16 weeks of pregnancy and miscarriage was recorded up to 20 weeks…

Esito…

… Among the women who reported drinking no coffee, the miscarriage rate was about 10 percent. Women who consumed a half cup to two cups a day had a slightly higher rate, but this difference is small. It’s also not statistically significant…. Women who consumed even more coffee (more than two cups a day and more than three and a half cups a day) had, if anything, lower rates of miscarriage…

Studio danese: caffè a volontà per tutti…

… This isn’t the only study to come to this conclusion – one in Denmark with almost 100,000 women similarly found no impact from up to three cups of coffee a day.22…

Attenzione: in California uno studio simile con risultati differenti…

… Around the same time this 2008 study came out, a similar study was released in California. The study design was very close: researchers recruited women early in pregnancy, interviewed them about how much coffee they drank and measured miscarriage up to 20 weeks. However, despite the similar design, the researchers came to somewhat different conclusions… researchers found no difference in miscarriage rates between women who drank no coffee and those who drank up to two cups a day. However, they did find higher miscarriage rates for those who drank more than two cups a day…

Ma la differenza è probabilmente da imputare all’effetto nausea…

… For some women and for the American Congress of Obstetricians and Gynecologists, this study may be enough to conclude that pregnant women should stick to less than two cups a day. For me, however, there were enough aspects of the study that gave me pause and suggested that perhaps this is just the nausea story all over again….

Ricordo che la nausea è sintomo di gravidanza eccellente ma fa anche passare la voglia di bere caffè.

Nello studio californiano sembra che conti la riduzione del consumo più che il livello assoluto. Chiaro indizio che l’effetto nausea interferisce…

… For one thing, the authors found no effect of coffee among women who reduced their consumption, regardless of what their final consumption level was. Taken literally, this means that it doesn’t matter how much coffee you drink, as long as you reduce from your starting level…

Altro indizio sospetto: perché il caffè fa male e la Coca no? Anche la Coca contiene caffeina, senonché la nausea non ne inibisce il consumo…

… As I poked around this research, there were a few other things that made me think the nausea story might be quite important. One was that other common sources of caffeine – tea and cola – are less consistently linked with miscarriage.25 These contain caffeine (although less than coffee), but tend to be easier on the stomach, so the confounding relationship with nausea is limited…

Terzo indizio: perché mai il decaffeinato dovrebbe essere pericoloso quanto il caffè normale?…

… I also found one clever study that showed that decaffeinated coffee was as strongly linked to miscarriage as caffeinated coffee. Decaf coffee has the same nausea problem, but no caffeine…

Conclusione:

… I decided the three to four cups a day I was having was fine…

Sondiamo le evidenze su un altro possibile danno procurato dal caffè: la crescita rallentata del feto.

Qui esiste uno studio random trial…

… The evidence is better for the simple reason that there is at least one randomised controlled trial (I guess it’s not impossible to get this by an ethical review board, just difficult). Researchers in Denmark recruited 1,207 pregnant women who were coffee drinkers (at least three cups a day). They were asked to be in the study before 20 weeks of pregnancy and the researchers recorded the birth weight of their babies and whether they were premature….

L’esperimento…

… Now here is the experiment: women were given free instant coffee. Half of them were given free caffeinated instant coffee and half were given free decaffeinated instant coffee. The women did not know which type of coffee they received (the boxes looked the same). They were asked to replace their usual coffee with the instant coffee from the study…

Esito: nessun effetto negativo…

… The caffeinated-coffee women had babies of the same weight and length after the same number of days of gestation and with the same head size. Other, non-randomised studies have reached similar conclusions…

E per consumi molto alti (più di 4 tazzine al giorno)?

L’effetto è segnalato ma “alti consumi”, “alta ingerenza” dell’effetto nausea…

… The first thing to note is that studies of women at this higher level of consumption are, if anything, even more subject to the concerns about nausea. If you are feeling at all nauseous, at any time of the day, you are probably not having eight cups of coffee. Perhaps for this reason – or, perhaps, because too much coffee really is a problem – studies are more consistent at showing a link…

Riassuntino:

… The Bottom Line • In moderation, coffee is fine. • All evidence supports having up to two cups. • Much of the evidence supports having three to four cups. • Evidence on more than four cups a day is mixed; some links are seen with miscarriage, but it is possible that they are all due to the effects of nausea….

***

Passiamo al fumo.

Fumare fa sempre male e fa sempre male anche al feto. Qui non c’è moderazione che tenga…

… If you smoke, your doctor has presumably encouraged you to quit. But quitting is hard and most smokers have tried at one time or another. The question in the case of pregnancy: is there any extra reason to quit while pregnant? The answer is a resounding yes. Smoking, even in moderate amounts, is bad for your baby…

Danni…

… low-birth-weight… higher risk for SIDS (sudden infant death syndrome, often called cot death)…

Il processo biologico all’opera…

… Tobacco contains a number of chemicals, but the two important ones are nicotine and carbon monoxide. Both of these restrict oxygen to the foetus. Less oxygen means less growth. Additionally, the blood vessel constriction caused by nicotine exposure can damage the placenta, which is the source of many pregnancy complications…

Mega studio in Missouri…

… Consider a representative study that analysed all births in Missouri, USA, between 1989 and 2005 (this amounted to more than one million babies).31 The authors in this study simply looked at whether women said they smoked during pregnancy and compared women who smoked to those who did not…

Effetti…

… Women who smoke are more likely to be anaemic and are much more likely to have problems with the placenta and to have pre-term labour or stillbirths. The impacts on birth weight are huge: if you smoke you are more than twice as likely to have a baby who is very small…

La moderazione non salva…

… Maybe moderate smoking is okay? No, it is not. The study in Missouri showed that women smoking one to nine cigarettes a day had just has many extra complications as those smoking more than a pack….

Conta smettere “durante”? In effetti chi molla ha qualche beneficio…

… Does it matter when during pregnancy you smoke? A study from the Netherlands published in 2008 looked at the timing of smoking.32 These authors found that smoking later in pregnancy had the largest effects on birth weight… Women who smoked more than nine cigarettes a day after 25 weeks had babies about 200 grams smaller than those who did not smoke; this is a 6 percent reduction in body weight! This means, among other things, that even if you smoke at the start of pregnancy, there are still huge benefits to quitting later on…

SIDS: più rischi per chi fuma…

… A study in the United Kingdom described differences in the risk of cot death in children of mothers who smoked and those who did not.33 Children of mothers who smoked one to nine cigarettes a day during pregnancy were more than four times as likely to die of cot death as those whose mothers did not smoke. Children of mothers who smoked 20 or more cigarettes a day were almost nine times as likely to die. Here is another way to look at it: 86 percent of cot deaths in the UK were among children of mothers who smoked…

E il fumo passivo? Conta anche quello…

… Second-hand smoke exposure (for example, from fathers or grandparents) also leads to many of the same negative outcomes. A 2010 review article found that babies of mothers who were exposed to second-hand smoke during pregnancy were about 57 grams lighter at birth than babies who were not.34 It’s worth saying that the women in these studies were exposed to a lot of smoke, like the amount that would come from living with a partner who smokes. Very occasional contact (a night with smokers, or walking by someone smoking on the street) is not a big deal…

Il fumo fa talmente male che in queste ricerche è possibile organizzare esperimenti random trial convincendo alcune future madri a smettere. Non tentare di convincere le altre mamme sembra eticamente tollerabile…

… precisely because people are convinced that smoking is bad and because it is hard to stop, there are randomised trials that do exactly the opposite: encourage women to quit smoking. Typically, these studies take a group of pregnant smokers and randomly assign half of them to some treatment that will hopefully reduce their smoking. If some of the women do quit smoking, we can learn about the impacts of smoking by comparing their babies with the babies of women in the control groups…

Esito…

… A 2008 review article summarised 64 studies just like this,36 16 of which also collected information on the babies. One thing we learn is that it’s really hard to quit smoking: of these 16 trials, only five actually got a significant number of women to quit. But among those studies we see benefits for the baby: women who were encouraged to quit had babies who were about 57 grams heavier… The impact of not smoking must be very large if we can see differences in average birth weight… The impacts on pre-term labour are even more striking…

Riassuntino…

… The Bottom Line Smoking during pregnancy is dangerous for your baby. *It’s hard to know why this is. As foetal alcohol syndrome is typically a result of binge drinking, it is possible that it could be due to the United States having more inequality in drinking – a lot of people not drinking at all and a few engaging in binge drinking – as opposed to European countries where most people drink moderately. **This graph reports co-efficients adjusted for maternal demographics and weight. ***This particular study observed a lot of information about children – including information on the drinking behaviour of the father – and after adjusting for everything about the child, they still found that test scores were unaffected by maternal drinking in pregnancy. ****These figures take the miscarriage rate for zero cups as the baseline and calculate the higher-intake groups by multiplying this baseline by the adjusted hazard ratio. You can read this as saying: if the group drinking eight cups of coffee was similar on all the other variables to the zero cups group, their miscarriage rate would be 1.9 percent, versus 1.2 percent in the zero cups group…