Recurrence of Preterm Birth and Early Term Birth

Abstract

OBJECTIVE To examine recurrent preterm birth and early term birth in women’s initial and immediately subsequent pregnancies. METHODS This retrospective cohort study included 163,889 women who delivered their first and second liveborn singleton neonates between 20 and 44 weeks of gestation in California from 2005 through 2011. Data from hospital discharge records and birth certificates were used for analyses. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using logistic regression models adjusted for risk factors. RESULTS Shorter gestational duration in the first pregnancy increased the risk of subsequent preterm birth (both early, before 32 weeks of gestation, and later, from 32 to 36 weeks of gestation) as well as early term birth (37–38 weeks of gestation). Compared with women with a prior term birth, women with a prior early preterm birth (before 32 weeks of gestation) were at the highest risk for a subsequent early preterm birth (58/935 [6.2%] compared with 367/118,505 [0.3%], adjusted OR 23.3, 95% CI 17.2–31.7). Women with a prior early term birth had more than a twofold increased risk for subsequent preterm birth (before 32 weeks of gestation: 171/36,017 [0.5%], adjusted OR 2.0, 95% CI 1.6–2.3; from 32 to 36 weeks of gestation: 2,086/36,017 [6.8%], adjusted OR 3.0, 95% CI 2.9–3.2) or early term birth (13,582/36,017 [37.7%], adjusted OR 2.2, 95% CI 2.2–2.3). CONCLUSION Both preterm birth and early term birth are associated with these outcomes in a subsequent pregnancy. Increased clinical attention and research efforts may benefit from a focus on women with a prior early term birth as well as those with prior preterm birth.

Are risk factors for preterm and early-term live singleton birth the same? A population-based study in France

“…The strongest single predictor of both preterm and early-term delivery was a previous preterm birth (overall and by mode of onset of delivery), as confirmed in other population-based studies 31 32 and a recent systematic review which showed a 30% risk of recurrent sPTB following sPTB in singleton pregnancies. 33 In contrast, first-time mothers were more likely to deliver preterm, but not early term indicating that the shape of the risk distribution for early delivery in primiparae may slightly differ from the overall GA distribution which peaks around 38–40 weeks of gestation.…”

Risk of preterm birth in a twin pregnancy after an early‐term birth in the preceding singleton pregnancy: a retrospective cohort study

“…Our findings are consistent with these results: women with a spontaneous singleton early‐term birth are at greater risk of PTB in a subsequent twin pregnancy than are women with a prior full‐ or late‐term birth, and this association persisted after adjustment for potential confounders. Our data and those of Yang et al show that the dichotomy between previous preterm and term birth is artificial for the risk of subsequent PTB: the risk is a continuum, and the lowest risk is observed only among women with a previous full‐ or late‐term birth.…”

“…Furthermore, this higher risk exists after both spontaneous and indicated PTBs . Yang et al recently reported that a shorter gestational duration in the first singleton pregnancy increases the risk of subsequent singleton PTB and early‐term birth; in particular, women with a prior early‐term birth are at higher risk of subsequent PTB than are women with a prior full‐ or late‐term birth. Our findings are consistent with these results: women with a spontaneous singleton early‐term birth are at greater risk of PTB in a subsequent twin pregnancy than are women with a prior full‐ or late‐term birth, and this association persisted after adjustment for potential confounders.…”

Prediction of preterm birth with and without preeclampsia using mid-pregnancy immune and growth-related molecular factors and maternal characteristics

“…It will also be important to examine how this test behaves in identifying pregnancies that deliver early term (37 and 38 weeks). Given mounting data demonstrating that early term babies are at increased risk for both short- and long-term morbidity [ 47 ] and that these women are more likely to deliver preterm in the next pregnancy [ 48 ] it would be advantageous to be able to identify these women early in pregnancy in an effort to extend gestation.…”