Impact of obstetric history on spontaneous preterm birth
The obstetric history: personal and family M Varner University of Utah, Salt Lake City, UT, USA Linked article: This is a mini commentary on Kazemier BM, Buijs PE et al., pp. 1197–1208 in this issue. To view this article visit http://dx.doi.org/10.1111/1471-0528.12896. Published Online 5 June 2014. It is well known that the best single predictor of spontaneous preterm birth (SPTB) in a given pregnant women is a personal history of a SPTB. This review emphasises the point that the recurrence risk in a given pregnancy varies substantially based on the circumstances of the penultimate gestation. Not surprisingly, recurrence risks vary by whether the preceding and current pregnancies are singleton or twin gestations. Obstetric care providers need to know these data in order to provide appropriate counselling on risks and care recommendations, both during antepartum care and immediately after a preterm birth. This reviewer suspects that the majority of obstetric care providers have encountered the scenario of recurrent preterm birth in which the woman and her family state that either no one talked to them about recurrence risks or that they were told it was a random event without substantive recurrence risks. This article focuses on SPTB, which is the dominant contributor to the continuing preterm birth pandemic. The authors correctly acknowledge that indicated preterm birth (IPTB) is an important contributor to
overall preterm birth rates, and there is evidence that IPTB in a previous pregnancy increases a woman’s risk of overall preterm birth in her subsequent pregnancy(ies) (Laughton et al. AJOG 2014;210:131.e1–8), although to a lesser extent than a previous SPTB. Readers of BJOG are all aware of the multifactorial nature of SPTB. There is evidence that recurrence risks may be affected by whether the previous SPTB occurred with intact membranes or following preterm premature rupture of the membranes (Gonzalea-Quintero et al. AJOG 2011; 205:275.e1–5). Likewise, gestational age is a continuum and recurrence risks are also inversely related to the gestational age of the previous preterm birth. SPTB recurrences, at least among singletons, also tend to occur at similar gestational ages (Esplin et al. Obstet Gynecol 2008;112:516– 23). Although this review was not designed to address the recurrence issue beyond primiparous women (with a second viable pregnancy), there is also evidence that term deliveries between a previous SPTB and the current pregnancy progressively decrease the recurrence risk.
ª 2014 Royal College of Obstetricians and Gynaecologists
Finally, if a woman’s past obstetric history influences her risk of preterm delivery in the current pregnancy, what impact does the obstetric histories of her first-degree relatives have on her pregnancy outcomes? There are compelling data to suggest that women who themselves were born prematurely are more likely to have their babies prematurely (Porter et al. Obstet Gynecol 1997;90:63–7). Likewise, a history of preterm birth in a sister (full- or half-sister) increases a woman’s risk. Similar risk increases are recognised for other pregnancy complications (e.g. pre-eclampsia and operative delivery). This article should remind us both of the importance of an obstetric family history in identifying pregnant women at risk for preterm birth and other pregnancy complications, and of the value of potentially appropriate preventive measures (progesterone, cerclage, pessary, semi-synthetic corticosteroids) in improving pregnancy outcomes for these women and their families.
Disclosure of interests The author has no conflicts of interest to disclose. &
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The obstetric history: personal and family M Varner University of Utah, Salt Lake City, UT, USA Linked article: This is a mini commentary on Kazemier BM, Buijs PE et al., pp. 1197–1208 in this issue. To view this article visit http://dx.doi.org/10.1111/1471-0528.12896. Published Online 5 June 2014. It is well known that the best single predictor of spontaneous preterm birth (SPTB) in a given pregnant women is a personal history of a SPTB. This review emphasises the point that the recurrence risk in a given pregnancy varies substantially based on the circumstances of the penultimate gestation. Not surprisingly, recurrence risks vary by whether the preceding and current pregnancies are singleton or twin gestations. Obstetric care providers need to know these data in order to provide appropriate counselling on risks and care recommendations, both during antepartum care and immediately after a preterm birth. This reviewer suspects that the majority of obstetric care providers have encountered the scenario of recurrent preterm birth in which the woman and her family state that either no one talked to them about recurrence risks or that they were told it was a random event without substantive recurrence risks. This article focuses on SPTB, which is the dominant contributor to the continuing preterm birth pandemic. The authors correctly acknowledge that indicated preterm birth (IPTB) is an important contributor to
overall preterm birth rates, and there is evidence that IPTB in a previous pregnancy increases a woman’s risk of overall preterm birth in her subsequent pregnancy(ies) (Laughton et al. AJOG 2014;210:131.e1–8), although to a lesser extent than a previous SPTB. Readers of BJOG are all aware of the multifactorial nature of SPTB. There is evidence that recurrence risks may be affected by whether the previous SPTB occurred with intact membranes or following preterm premature rupture of the membranes (Gonzalea-Quintero et al. AJOG 2011; 205:275.e1–5). Likewise, gestational age is a continuum and recurrence risks are also inversely related to the gestational age of the previous preterm birth. SPTB recurrences, at least among singletons, also tend to occur at similar gestational ages (Esplin et al. Obstet Gynecol 2008;112:516– 23). Although this review was not designed to address the recurrence issue beyond primiparous women (with a second viable pregnancy), there is also evidence that term deliveries between a previous SPTB and the current pregnancy progressively decrease the recurrence risk.
ª 2014 Royal College of Obstetricians and Gynaecologists
Finally, if a woman’s past obstetric history influences her risk of preterm delivery in the current pregnancy, what impact does the obstetric histories of her first-degree relatives have on her pregnancy outcomes? There are compelling data to suggest that women who themselves were born prematurely are more likely to have their babies prematurely (Porter et al. Obstet Gynecol 1997;90:63–7). Likewise, a history of preterm birth in a sister (full- or half-sister) increases a woman’s risk. Similar risk increases are recognised for other pregnancy complications (e.g. pre-eclampsia and operative delivery). This article should remind us both of the importance of an obstetric family history in identifying pregnant women at risk for preterm birth and other pregnancy complications, and of the value of potentially appropriate preventive measures (progesterone, cerclage, pessary, semi-synthetic corticosteroids) in improving pregnancy outcomes for these women and their families.
Disclosure of interests The author has no conflicts of interest to disclose. &
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