Do patients who deliver at term after being hospitalized for preterm contractions have an increased risk for obstetrical complications?

Further Evidence that an Episode of Premature Labor Is a Pathologic State: Involvement of the Insulin-Like Growth Factor System

INTRODUCTION

Approximately 47% of women with an episode of preterm labor deliver at term; however, their infants are at greater risk of being small for gestational age and for neurodevelopmental disorders. In these cases, a pathologic insult may disrupt the homeostatic responses sustaining pregnancy. We tested the hypothesis of an involvement of components of the insulin-like growth factor (IGF) system.

METHODS

This is a cross-sectional study in which maternal plasma concentrations of pregnancy-associated plasma protease (PAPP)-A, PAPP-A2, insulin-like growth factor-binding protein 1 (IGFBP-1), and IGFBP-4 were determined in the following groups of women: (1) no episodes of preterm labor, term delivery (controls, n = 100); (2) episode of preterm labor, term delivery (n = 50); (3) episode of preterm labor, preterm delivery (n = 100); (4) pregnant women at term not in labor (n = 61); and (5) pregnant women at term in labor (n = 61). Pairwise differences in maternal plasma concentrations of PAPP-A, PAPP-A2, IGFBP-1, and IGFBP-4 among study groups were assessed by fitting linear models on log-transformed data and included adjustment for relevant covariates. Significance of the group coefficient in the linear models was assessed via t-scores, with p < 0.05 deemed a significant result.

RESULTS

Compared to controls, (1) women with an episode of premature labor, regardless of a preterm or a term delivery, had higher mean plasma concentrations of PAPP-A2 and IGFBP-1 (each p < 0.05); (2) women with an episode of premature labor who delivered at term also had a higher mean concentration of PAPP-A (p < 0.05); and (3) acute histologic chorioamnionitis and spontaneous labor at term were not associated with significant changes in these analytes.

CONCLUSION

An episode of preterm labor involves the IGF system, supporting the view that the premature activation of parturition is a pathologic state, even in those women who delivered at term.

Long-term childhood outcomes for babies born at term who were exposed to antenatal corticosteroids

BACKGROUND

Antenatal corticosteroids improve neonatal outcomes when administered to infants who are at risk of preterm delivery. Many women who receive antenatal corticosteroids for threatened preterm labor proceed to deliver at term. Thus, long-term outcomes should be evaluated for term-born infants who were exposed to antenatal corticosteroids in utero.

OBJECTIVE

This study aimed to compare long-term outcomes between term-born children aged ≥5 years who were born to women who received antenatal corticosteroids for threatened preterm labor and children whose mothers were also evaluated for threatened preterm labor but did not receive antenatal corticosteroids.

STUDY DESIGN

We performed a retrospective cohort study of children born at ≥37 weeks' gestation, aged ≥5 years, and born to mothers diagnosed with threatened preterm labor during pregnancy. The primary exposure of interest was receiving antenatal corticosteroids. Among the collected childhood medical conditions, the primary outcome of interest was a diagnosis of asthma.

RESULTS

Of the 3556 term-born children aged ≥5 years, 629 (17.6%) were exposed to antenatal corticosteroids (all betamethasone), and 2927 (82.3%) were controls whose mothers were evaluated for threatened preterm birth but did not get antenatal corticosteroid injections. Women receiving antenatal corticosteroids had higher rates of maternal comorbidities (diabetes mellitus, hypertension; P≤.01). Antenatal corticosteroid-exposed children had no difference in diagnosis of asthma (12.6% vs 11.6%), attention deficit disorder, or developmental delay (P=.47, .54, and .10, respectively). Controlling for maternal and neonatal characteristics, asthma was not different between those exposed to antenatal corticosteroids and controls (odds ratio, 1.05; 95% confidence interval, 0.79-1.39). The odds of the child's weight percentile being <10% were increased for antenatal corticosteroid-exposed children born at term (odds ratio, 2.00; 95% confidence interval, 1.22-3.25).

CONCLUSION

Children born at term who were exposed to antenatal corticosteroids may have increased odds of being in a lower growth percentile than those not exposed. However, rates of diagnoses such as asthma, developmental delay, and attention deficit disorders were not different.

Are infants born after an episode of suspected preterm labor at risk of attention deficit hyperactivity disorder? A 30-month follow-up study

BACKGROUND

An episode of suspected preterm labor may be by itself a pathologic event that may alter the normal course of pregnancy and the offspring's neurodevelopment. Certainly, the association between preterm birth and neurodevelopmental disorders can only be partially explained by the immaturity of the nervous system, as evidenced by the increased risk of attention deficit hyperactivity disorder in late-preterm infants without any neurologic alteration.

OBJECTIVE

This study aimed to examine whether infants born after suspected preterm labor may be at an increased risk of developing attention deficit hyperactivity disorder. Moreover, potential obstetrical, perinatal, and psychosocial risk factors associated with attention deficit hyperactivity disorder in this population are examined.

STUDY DESIGN

A prospective cohort study of 120 mother-infant pairs was conducted from the moment the mothers received a diagnosis of suspected preterm labor until the infants' 30 months of life. Infants were divided according to the prematurity status: full-term infants born after a suspected preterm labor (n=28; born at ≥37 weeks of gestation), late-preterm infants (n=56; born between 32 and <37 weeks of gestation), very-preterm infants (n=36; born before <32 weeks of gestation). At-term infants born without obstetric complications served as a control group (n=46). Infants' attention deficit hyperactivity disorder symptoms were assessed at the age of 30 months. Furthermore, obstetrical, perinatal, and psychosocial risk factors were recorded.

RESULTS

All groups of infants born after a suspected preterm labor showed more attention deficit hyperactivity disorder symptoms at the age of 30 months than the control group. Concretely, very-preterm infants showed higher restless or impulsive behaviors, whereas full-term infants born after a suspected preterm labor and late-preterm infants showed higher emotional lability behaviors. Among potential risk factors, male sex and maternal experience of posttraumatic stress symptoms predicted the severity of attention deficit hyperactivity disorder symptoms in infants born after a suspected preterm labor.

CONCLUSION

Infants born after a suspected preterm labor had a higher risk of developing attention deficit hyperactivity disorder symptoms, including those born at term. Infants born after a suspected preterm labor showed a distinctive phenotype and shared specific risk factors suggesting that they conform an undescribed population at risk of attention deficit hyperactivity disorder.

Severe maternal infectious morbidity during the second half of pregnancy is an independent risk factor for a small for gestational age neonate

OBJECTIVE

The effect of severe maternal infectious morbidity on fetal growth during the second half of pregnancy is under debate. Preliminary evidence suggests that such association may be plausible. The objectives of this study were to determine: 1) The association between severe maternal infectious morbidity and adverse pregnancy outcome; and 2) The effect of maternal infection during pregnancy on fetal growth.

STUDY DESIGN

This retrospective population - based cohort study included 4771 women who gave birth at our medical center during the study period. Parturients were allocated into two groups: 1) patients with severe maternal infection during the second half of pregnancy (n = 368); and 2) control group comprised of normal pregnant women who were matched to the study group by maternal age, gravidity and parity (n = 4403).

RESULTS

The severe maternal infection group included women with pneumonia (n = 198), pyelonephritis (n = 131), and viral pneumonitis (n = 39). In comparison to the normal patients group: 1) having had pneumonia during the second half of pregnancy was associated with increased rates of fetal growth restriction, placental abruption, fetal demise (P < 0.001, for all comparisons) and preeclampsia (P = 0.041); 2) Pyelonephritis during the second half of gestation was associated with higher rates of fetal growth restriction (P < 0.001), placental abruption (P = 0.006) and labor induction (P = 0.039). As a group, women with severe maternal infection had higher rates of small for gestational age neonates compared to normal parturients (P < 0.001). Among women with infections, only those who had pyelonephritis (P = 0.032) or pneumonia (P = 0.008), had a higher rate of small for gestational age neonates than those in the control group. After adjustment to confounding factors, maternal infection (OR = 1.42, 95% CI 1.085-1.85) and previous delivery of a small for gestational age neonate (OR = 2.54, 95% CI 2.02-3.19), were independent risk factors for the delivery of a small for gestational age neonate.

CONCLUSION

Severe maternal infectious morbidity during the second half of pregnancy is an independent risk factor for the delivery of a small for gestational age neonate and is associated with adverse pregnancy outcomes. Both, pneumonia and pyelonephritis, during the second half of gestation affect fetal growth and are related to higher rates of small for gestational age neonates.

Can 17 hydroxyprogesterone caproate (17P) decrease preterm deliveries in patients with a history of PMC or pPROM?

BACKGROUND

A history of spontaneous preterm birth (sPTB) is a significant risk factor for recurrence. Intra-muscular-7α-hydroxyprogesterone caproate (17P) has been the preventive treatment of choice until the recent "Prolong study" that reported no benefit.

OBJECTIVE

To determine the benefit of (17P) treatment in preventing reoccurrence of sPTB, by evaluating two presenting symptoms of the first sPTB: premature contractions (PMC) and preterm premature rupture of membranes (pPROM).

STUDY DESIGN

This retrospective study included 342 women with a previous singleton sPTB followed by a subsequent pregnancy. sPTB were either due to PMC (n = 145) or pPROM (n = 197). During the subsequent pregnancy, 90 (26.3%) patients received 250 mg 17P IM. Each presenting symptom-PMC or pPROM-was evaluated within itself comparing treated vs. untreated groups. Data were analyzed using t-test, Chi-square and Fisher's exact test. Logistic regression analysis was also performed.

RESULTS

Patients treated with 17P in the subsequent pregnancy had delivered earlier in the previous pregnancy (33.4w vs. 35.3w in the PMC group, and 34.1w vs. 35.7w in the pPROM group, p<0.001). In the following pregnancy, they had higher admission rates due to suspected preterm labor (31.7% vs. 10.9% in the treated vs. untreated PMC group (p = 0.003) and 26.1% vs. 5.4% in the treated vs. untreated pPROM group (p<0.001). In both groups, but more prominently in the previous PMC group, treatment compared to non-treatment in the subsequent pregnancy significantly prolonged it (4.3w vs. 2.6w in the PMC group (p = 0.007), and 3.7w vs. 2.7w in the pPROM group (p = 0.018)). The presenting symptom of sPTB in the following pregnancy tended to recur in cases of another sPTB, with a significantly greater likelihood of repeating the sPTB mechanism in cases with PMC, regardless of receiving 17P (69% in the PMC cohort and 60% in the pPROM cohort, p<0.001).

CONCLUSIONS

17P might delay preterm delivery in patients with a previous sPTB on an individual level (prolongation of the pregnancy for each patient compared to her previous delivery). Therefore, our results imply that 17P can decrease potential premature delivery complications for patients with a previous sPTB due to PMC or pPROM.

Perceived stress and its predictors in women with threatened preterm labour: A cross-sectional study

AIM

To determine prevalence and predictors of perceived stress in women with threatened preterm labour.

DESIGN

Cross-sectional.

METHODS

We recruited 409 women with threatened preterm labour, hospitalized at two tertiary hospitals. We assessed their socio-demographic and obstetrics characteristics, and their perceived stress, perceived social support, experience of violence using validated scales. Multiple linear regression was used to determine the predictors.

RESULTS

Data from all recruited women were analysed. Most of them had borderline (36%) or high (42%) level stress. Overall, 17 predictors were identified explaining 89.5% of variation in the stress score. Predictors of the higher stress score included: urban living, experience of sexual and psychological violence, perceived insufficient social support, experience of vaginal bleeding during current pregnancy, abnormal results in initial pregnancy tests, having multiple roles at home, being less than 28 weeks pregnant, being parous, sleep disorders, history of health problems, insufficient income and unwanted pregnancy.

The association between threatened preterm labour and perinatal outcomes at term: a population-based cohort study

OBJECTIVE

To estimate the association between threatened preterm labour (TPTL) and perinatal outcomes of infants born at term.

DESIGN

A population-based cohort study of perinatal outcomes following TPTL <37 weeks of gestation with delivery at term.

SETTING

Nova Scotia, Canada.

POPULATION

All non-anomalous, singleton pregnancies ≥37 weeks of gestation without antepartum haemorrhage from 1988 to 2019.

METHODS

Using data from the Nova Scotia Atlee Perinatal Database, TPTL was defined as pregnancies with a hospital admission between 20 and 37 weeks of gestation, with a diagnosis code denoting TPTL with administration of antenatal corticosteroids, or with administration of any tocolysis. Poisson regression models were used to estimate the risk ratios (RR) with 95% CI of maternal and perinatal outcomes in women who had an episode of TPTL relative to those who did not.

MAIN OUTCOME MEASURES

Birthweight for gestational age below the tenth centile and a composite of perinatal mortality or severe perinatal morbidity.

RESULTS

Of 256 599 term deliveries meeting the inclusion criteria, 2278 (0.9%) involved TPTL. The risks of the primary outcomes were higher among those with TPTL relative to those without: birthweight for gestational age below the tenth centile (RR 1.24, 95% CI 1.11-1.39) and the composite of perinatal mortality/severe perinatal morbidity (RR 1.33, 95% CI 1.15-1.54).

CONCLUSIONS

Although the prevalence of TPTL in term deliveries is low, affected pregnancies are at increased risk for adverse perinatal outcomes. Increased fetal surveillance should be considered in the management of pregnancies affected by TPTL.

Altered DNA methylation in human placenta after (suspected) preterm labor

Aim: The aim of this study was to determine if alterations in DNA methylation in the human placenta would support suspected preterm labor as a pathologic insult associated with diminished placental health. Methods: We evaluated placental DNA methylation at seven loci differentially methylated in placental pathologies using targeted bisulfite sequencing, in placentas associated with preterm labor (term birth after suspected preterm labor [n = 15] and preterm birth [n = 15]), and controls (n = 15). Results: DNA methylation levels at the NCAM1 and PLAGL1 loci in placentas associated with preterm labor did differ significantly (p < 0.05) from controls. Discussion: Specific alterations in methylation patterns indicative of an unfavourable placental environment are associated with preterm labor per se and not restricted to preterm birth.