In North America, between 1916 and the 1980s, a period of almost 70 years, giving birth vaginally after a caesarean was not encouraged. A caesarean was generally automatically repeated except when the birth took place so fast that there was no time to perform an elective caesarean. But it is not true that VBAC was never authorised in North American hospitals prior to the 1970s and 1980s. VBAC had always been practised in some hospitals, thanks to the presence of physicians who had been trained in Europe and who were used to considering VBAC as normal.
Many nurses as well as a physician, Dr Maurice Marinier, ex-chief of the Obstetrics Department of Ste-Jeanne-d’Arc Hospital in Montr´eal, have confirmed this to me.
However, after the 1970s and 1980s, VBAC was prohibited by obstetricians and gynaecologists. It was only following the American and Canadian consensus conferences on caesarean held, respectively, in 1979 and 1985 that hospitals began implementing policies favouring VBAC (Vadeboncoeur 1989).
‘Once a caesarean, always a caesarean’, misinterpreted?
In fact, the famous aphorism ‘Once a caesarean, always a caesarean’, pronounced by Dr Edward B. Craigin before his colleagues at a conference in New York in 1916, was not meant to be taken literally. Actually, what followed was that ‘Many exceptions occur’ (Craigin 1916). This implies that the speaker did not necessarily intend to establish a rule. In fact, as early as 1933, VBACs took place in a New York hospital. Moreover, in the 1950s, studies were published on the subject.
Meanwhile, there was a change in the type of uterine incision and as a result VBAC became safer, but as stated in 1966, ‘the medical profession as a whole appears profoundly reluctant to accept this’ (O’Connell 1966). An increasing number of studies were published in the following decade but in more than 99% of cases, repeat caesareans continued to be performed (Vadeboncoeur 1989).
Women’s demands
In the mid-1970s, women’s demands for VBAC began to increase, whereas the caesarean rate rose at breathtaking speed. Women’s groups were formed. At first, they emphasised the importance of giving information on caesarean births and on ways to prevent them. Later, at the beginning of the 1980s, VBAC support groups appeared. Then, works were published in the United States and Canada by women wishing to alert public opinion on the automatic repetition of caesareans (Cohen and Estner 1983; Koehler 1985; Baptisti Richards 1987).
Governments and medical associations take their positions
Meanwhile and probably as a result of the work of these groups, many official stands were taken in the 1980s in favour of VBAC. For the first time, in North America, it was officially stated that giving birth vaginally after a caesarean is safe and that risks are low if the uterine incision is of the type known as low transverse.
The World Health Organization (WHO) explored appropriate technology for birth at a conference held in Brazil in 1985. The following recommendation was then adopted unanimously:
There is no evidence that caesarean section is required after a previous caesarean section birth. Vaginal deliveries after a caesarean should normally be encouraged wherever emergency surgical intervention is available.
(World Health Organization 1985)
In the United States, a national consensus conference on caesareans held by the National Institute of Health in 1979 dealt for the first time with VBAC. The ACOG published its first guidelines on the subject in 1982. In Canada, the National Consensus Conference on Aspects of Caesarean Births held in 1985 recommended a ‘trial of labour’ for women who had a caesarean by low transverse incision provided it is a vertex presentation and that there is no absolute indication for a caesarean, for example, a placenta praevia. The first important research carried out over 3 years (1982–1985) had concluded that there was no difference in uterine rupture rate after one or more than one caesarean (Vadeboncoeur 1989). Finally, a study published in 1988 comes to the conclusion that ‘having more than one caesarean should not, therefore, prevent a woman from having a vaginal birth subsequently’ (Pruett et al. 1988). This is probably why the American College of Obstetricians and Gynaecologists reviewed its policies on VBAC the same year and declared that women should be encouraged to give birth vaginally after one or more caesareans. Moreover, the ACOG explicitly stated that no special measures are required for these births, none other than those existing everywhere for any birth, namely, the possibility to resort to a caesarean delivery within a 30-minute period.
The North American consensus conferences on caesarean and the subsequent positions taken by medical associations, in conjunction with women’s demands, without doubt contributed to the important rise of the VBAC rate. In Quebec, for example, between 1981 and 1997, it rose from 1.5% in 1981–1982 to 38.5% in 1997–1998 (Figure 3.1).
Fall in VBAC rate
Figure 3.1 shows that from 1997 to 1998, the VBAC rate decreased in Quebec. This phenomenon continues to date. It is consistent with the trend common to Canada and the United States. In fact, the VBAC rate in Canada between 1997–1998 and 2001–2002 has decreased from 35 to 27% (Canadian Institute for Health Information 2004), whereas in the United States it was a mere 9.2% (Rubin 2005) in 2004, having decreased by 67% since 1996 (Hoyert et al. 2006) (it reached a peak of 27.4% in 1997; Figure 3.2 [Martin et al. 2003]). What has occurred in North America to bring about such a drop in the VBAC rate even though North American medical associations supported this option and an increasing number of pregnant women favoured it? A VBAC rate decline has also been observed in the United Kingdom where, for instance, in Scotland the VBAC rate has gone down from 41 to 36% between 1991 and 1997.
0 5 10 15 20 25 30 35 40 45
1981–19821982–19831986–19871987–19881988–19891989–19901990–19911991–19921992–19931993–19941994–19951995–19961996–19971997–19981998–19991999–20002000–20012001–20022002–20032003–20042004–20052005–2006
Percentage
Figure 3.1 Evolution of VBAC rate in Quebec (1981–1982 to 2005–2006).
Source: Minist`ere de la sant´e et des services sociaux du Qu´ebec, Statistiques -Accouchements et naissances. www.msss.gouv.qc.ca. Reproduced with permission from Martin Renaud.
19890 5 10 15 20 25 30 35
Rate per 100
1991 1993 1995
VBC1
Total cesarean2 Primary cesarean3
1997 Year
1Number of vaginal births after previous cesarean per 100 live births to women with a previous cesarean delivery.
2Percentage of all live births by cesarean delivery.
3Number of primary cesare an deliveries per 100 live births to women who have not had a previous cesarean.
4Preliminary data.
1999 2001 2003 20044
Note : Due to changes in data collection from implementation of the 2003 revision of the US Standard Certificate of Live Birth, there may be small discontinuities in rates of primary cesarean delivery and VBAC in 2003 and 2004; see 'Technical Notes'.
Figure 3.2 Total and primary cesarean rate and vaginal birth after previous cesarean (VBAC): United States, 1989–2004.
Source: www.vbac.com. Reproduced with permission from Nicette Jukelevics.
Why has there been an important decline of the VBAC rate in the last decade?
VBAC started to be studied scientifically around the beginning of the 1980s: more studies were published in the 1990s, and this trend has not stopped since. The following section explores the contributions of the studies published in the 1980s and 1990s to what happened to VBAC.
Studies during the 1980s and 1990s
Most studies on VBAC are observational studies as opposed to experimental studies, also called controlled trials. Scientists consider randomised controlled trials (RCTs) the most valid type of studies. However, as noted by the author of a Cochrane publication, RCTs on VBAC do not exist. In their book on obstetrical practices, Enkin et al. (2000) had concluded that ‘in the absence of randomised trials, both patient choice and physician choice are involved’. It should be noted that no randomised trials on VBAC existed until recently probably because it was not considered ethically correct to oblige women to experience one or the other option. In Australia, an RCT is presently being done: the ACTOBAC (also called birth after caesarean), a collaborative RCT of birth after caesarean. Several hospitals have apparently begun recruiting pregnant women. Groups representing women or consumers have objected, questioning the ethics of randomly assigning healthy women with uncomplicated pregnancies to major surgery. They also question the investigation of babies’ health but not of women’s health, and wonder if the women recruited are given accurate and reliable information on the pros and cons of both options (http://www.canaustralia.net/?q=node/32). The RCT is conducted by University of Adelaide, North Adelaide, SA, Australia.
Even though many studies on VBAC are retrospective studies (carried out after the events concerned and based on obstetrical files, codified interventions, etc.), a small percentage – usually the more recent ones – are prospective, i.e. they were initiated prior to the events under study. In the latter case, the data collected are more reliable since everything is planned, well defined and conducted in accordance with a uniform procedure. Studies of this type are more difficult to carry out; they take more time and require additional resources: a very large number of births extending over many years or happening in several institutions are needed to obtain the variables to be measured for VBAC, especially the variables pertaining to maternal and perinatal mortality, relatively rare events.
On the other hand, with experimental studies such as RCT, it is possible to have more effective control on the validity and reliability of the data obtained.
Unfortunately, there is no consensus on the validity of studies on VBAC. Some believe that the level of scientific evidence of these studies is low or relatively low.
Others, like Enkin et al. (2000) think that VBAC should be encouraged because there is sufficient evidence of its safety. Outcomes of studies vary, however. Thus, according to the report of the Agency for Healthcare Research and Quality
In the best available studies, some outcomes were better in women who had a planned VBAC and some were better in those who had a planned repeat caesarean, whereas data were conflicting or insufficient for other outcomes.
(Guise et al. (2003), p. 633)
Sakala (2003), an expert in the field of scientific outcomes in the United States states that considering this report, every woman with a previous caesarean section should be given all the information she needs to make an enlightened choice and that research on this subject should continue.
On the other hand, the studies conducted to date are not without failings. Many of those quoted hereafter are criticised, even in the scientific reviews in which they are published. Thus, the American writer, Goer (2003), author of The Thinking Woman’s Guide to a Better Birth, talks of ‘Spin Doctoring the Research’, in the scientific publication Birth. Goer denounces not only the methodology employed for many of these studies – therefore questioning their conclusions – but also claims that the media propagated false outcomes. As a result, she says, not only health professionals but also pregnant women and couples expecting a baby were equally misled. This can be very harmful for the parents’ and their baby’s welfare.
This appears to have happened with a major study on VBAC, conducted by Lydon-Rochelle et al. (2001), which is discussed later in this chapter.