Inside Story

Pregnancy: guidelines and timelines

Two accounts of getting, and being, pregnant tell only part of the story about conception and childbirth

Jacinta Halloran 6 November 2014 2047 words

Stephanie Wunderlich/Ikon Images/Corbis

Expecting Better: Why the Conventional Pregnancy Wisdom Is Wrong – and What You Really Need to Know
By Emily Oster | Orion | $22.99

The Big Lie: Motherhood, Feminism, and the Reality of the Biological Clock
By Tanya Selvaratnam | Prometheus Books | $38


On a glorious spring Saturday recently, hundreds of midwives, GPs and obstetricians sat in a vast conference room, curtains drawn against the sun, listening to expert speakers from one of Melbourne’s large public obstetric hospitals expounding the latest treatment protocols for pregnancy and intrapartum care. Professor Michael Permezel, the president of the Royal Australian and New Zealand College of Obstetrics and Gynaecology, or RANZCOG, outlined new guidelines for screening for gestational diabetes, under which all pregnant women will now be offered an oral glucose tolerance test, rather than the simpler oral glucose challenge test, in the second trimester.

While the simpler test is less expensive and more patient-friendly – there’s no need to fast, for instance – it is less than ideally sensitive. Up to a quarter of cases of gestational diabetes, a significant condition with health implications for mother and baby, are missed by the current two-step process, in which hospitals only administer the more sophisticated test if the first test picks up abnormally high blood sugar. Diagnosis and treatment of gestational diabetes is delayed, sometimes beyond thirty weeks, because of delays in arranging and performing a follow-up test, and some women don’t ever get the second test. This new guideline, backed by research from several large multicentre clinical trials, was reached by consensus among representatives of nine health bodies made up of specialist doctors, public health researchers, nursing staff, allied health professionals and consumers.

In her pregnancy self-help manual, Expecting Better, Emily Oster, mother of one, promises to take a new broom to the “tired old myths” of pregnancy care. She’s also prepared to tackle a couple of consensus guidelines, though diabetes screening is left untouched. The subtitle of her book, “Why conventional pregnancy wisdom is wrong – and what you really need to know,” invites the question, “Why should Oster, albeit an economics professor with a PhD, know more about antenatal care than, say, the American College of Obstetrics and Gynaecology or RANZCOG?” Call me a curmudgeonly medico, but the premise of Oster’s book implies a conspiracy of misinformation, or at the very least silence, on the part of obstetricians and midwives everywhere. Indeed, she portrays her own obstetrician as a fairly wooden and unforthcoming doctor who, when pressed, provides incorrect or woolly answers. Oster seems to suggest that definitive information is lacking simply because no one has bothered to evaluate the evidence properly. This isn’t true.

Take, for instance, her stance on alcohol. After looking at some large prospective studies (two of which were Australian) on alcohol consumption in pregnancy and subsequent behavioural problems and IQ in offspring, Oster concludes that “there is no good evidence that light drinking during pregnancy impacts your baby. This means up to one drink a day in the second and third trimesters and one to two drinks a week in the first trimester.” (These conclusions are stated under the heading “The Bottom Line,” a summary of Oster’s recommendations that appears at the end of every chapter.) Now, compare Oster’s advice with that of RANZCOG:

Alcohol is a teratogen [a substance that can cause birth defects]. The sensitivity of the fetus to the adverse effects of alcohol varies between women and between the different stages of gestation. Internationally there is no consensus on the safe level of alcohol during pregnancy and breast-feeding.

There is good quality evidence that drinking excessive amounts of alcohol during pregnancy can damage fetal development. However, the minimum or threshold level at which alcohol begins to pose a significant threat to pregnancy is not known. The likelihood of an adverse fetal effect increases with increased volume and frequency of alcohol consumption. Until better evidence is available, RANZCOG currently recommends that women avoid intake of alcohol during pregnancy.

The RANZCOG working party involved in establishing alcohol guidelines will have examined the same research as Oster (and probably more besides) and come to a different conclusion about alcohol consumption in pregnancy: that is, to avoid it altogether until better evidence comes to hand. Conservative? Yes, but understandably so, given the responsibility of the task. Doctors everywhere see medical practice guide- lines, obstetric or otherwise, as up-to-date, best-practice resources for guiding patient care. (I should add here that guidelines, while valuable, are not meant to be strictly prescriptive: patient preferences and values, clinician values and experience, and the availability of resources must also be included in the mix.) Guidelines are, by their very nature, firmly evidence-based: if there isn’t good evidence for a safe level of drinking in pregnancy, the guidelines must reflect that lack of assurance.

“No amount of alcohol has been proven safe” is the phrase to which Oster most objects. Her counter-argument is that “too much of anything can be bad.” She cites two examples: Tylenol (the US trade name for acetaminophen, which we call paracetamol) and carrot juice (potentially causing Vitamin A toxicity if massive quantities were consumed). I find this choice of examples confusing: while Vitamin A, a retinoid, is known to be teratogenic at high levels, there’s no evidence that acetaminophen is, although it will cause liver failure in overdose.

“The statement that occasional drinking has not been proven safe could be applied to virtually anything in pregnancy,” Oster adds. I don’t agree. Alcohol is a known teratogen, at least at higher doses. Surprising as it may seem, not many readily ingested substances are.

Oster devotes 272 pages of her book to the common, almost universal aspects of conception, pregnancy and birth, at least in the Western world. Timing of conception; folate intake; the vices (her word) of caffeine, alcohol and tobacco; foods to avoid; nausea in pregnancy; prenatal genetic screening; options in labour – these issues and more are discussed in depth, the relevant studies analysed, Oster’s conclusions drawn. Eight pages out of 280 are given to the rarer and more concerning events of pregnancy: premature labour and high-risk pregnancy. In this chapter Oster includes eight conditions, each explained with a few bullet points, but interestingly doesn’t include her own Bottom Line recommendations.

Ultimately, after all the hype of the front cover is stripped away, Oster’s recommendations don’t differ much at all from those of most health professionals in this country. And she equivocates too, as well she might, when she tries to interpret studies that include few participants or are not well-designed, showing small yet significant correlations, say between different maternal sleeping positions and risk of stillbirth. So much information, and much of it difficult to interpret – which is why clinical practice guidelines are written in the first place.

Would I recommend this book to my pregnant patients? Perhaps, but only to those who are very keen to be inform-ed at every level (and by that I mean to the point of deliberating over decisions such as whether to have a glass of champagne at their best friend’s wedding). Oster’s book wouldn’t be enough of an antenatal resource itself, as no mention is made of foetal growth and development, routine antenatal testing (though she does include an informative and sensible chapter on genetic screening) or stages of labour. Oster has a likeable, chirpy style and has clearly done loads of research, and she focuses her attention on the common antenatal concerns that, at times, it must be said, doctors don’t spend as much time discussing with their healthy pregnant patients as might be desired. But an obstetrician’s day is still only twenty-four hours long, and adequate time must be given to the pointy end of pregnancy: women in labour, and those with significant and serious obstetric conditions, such as those mentioned in the eight pages of Oster’s 280-page book.


Like Expecting Better, Tanya Selvaratnam’s The Big Lie is both personal journey and crash course in medical facts and figures, but this time the cited research is on the sobering topic of infertility. Unlike Oster’s book, The Big Lie takes a broader sociopolitical approach to its subject matter. The big lie of the title relates to the feminist goal of “having it all”: that is, motherhood and career. For women of Selvaratnam’s milieu – middle-class, educated women born in the seventies and raised in the invigorating wash of feminism’s second wave – this goal has been deeply internalised.

Selvaratnam’s treatment of the motherhood/career dichotomy is largely temporal. In the author’s words, “The Big Lie is that women can do what they want on their own timetables.” Her point is not that women lose out by juggling family and work, but that women who want both need to be mindful, very mindful, of the ticking biological clock. More mindful, indeed, than the author, for this, dear readers, is a cautionary tale. Selvaratnam relates the joy of finding the right man at age thirty-seven, the shock of her first miscarriage and the grief of two more. At age forty she and her husband are about to commence IVF when she is diagnosed with an uncommon gastrointestinal cancer and requires extensive surgery. And soon after that her husband leaves her. At the end of the book Selvaratnam is divorced and childless, but optimistic that she’ll have a child, biologically or otherwise. There’s a sad, generous but somewhat amorphous wisdom she imparts at the end of this rather harrowing journey, a wisdom summed up in six maxims (or what she calls Action Items):

Share your stories.
Know your fertility.
Free yourself from convention.
Strategize for your goals.
Don’t be afraid of feminism.
Advocate for a better future.

The stress that both infertility and its treatment place on couples is well-recognised, I think, at least here in Australia. Sadly, Selvaratnam and her husband were not offered psychological support during the time of her miscarriages and IVF treatment, and this omission no doubt had significant bearing on the breakdown of their relationship. But she doesn’t make this point emphatically enough. If her book is supposed to be instructive, I would like to have seen more practical advice of this nature.

Selvaratnam provides a lot of factual information about infertility, and interviews many women who’ve experienced it, but the predominant narrative, her own, seems out of kilter with her broader message. This is partly because she doesn’t actually undergo IVF treatment – the cancer diagnosis and surgery intervene, and then her relationship breaks down – so the highs and lows of treatment are never explored at a personal level. And the academic information she imparts is not new. Her central point – delaying motherhood is a risk because fertility declines with age – is hardly a well-kept secret in 2014. Selvaratnam regrets her ignorance of this fact, but is unsure how she could have remedied it. “Like most women,” she writes, “I grew up without every really learning the most basic facts about the impact of delaying motherhood. I could have educated myself, but how was I supposed to look for information?”

I think the information was there for Selvaratnam to find, at least by the time she was in her mid thirties, but her lack of knowledge probably points not to lack of access to advice, but to the likelihood that pregnancy was not top of her mind. And therein lies the rub: information on age-related fertility is useful and empowering, but it only goes so far. Many other factors – the right partner (or any partner at all), financial security, completion of studies, personal health, one’s friends having children – all commonly feed into the decision about whether and when to have a baby. Personal chronology is only one of many factors.

Selvaratnam is at pains not to blame feminism for the perpetration of the “lie” that one can have it all at one’s own pace. Hers is a collaborative and information-seeking approach, and for that I commend her. •