Postterm births: are prolonged pregnancies too long?

Determinants of Meconium-Stained Amniotic Fluid at Hadiya Zone Hospitals, Southern Ethiopia; Unmatched Case-Control Study

Background

Meconium-stained amniotic fluid (MSAF) refers to an amniotic fluid that is green in color or mixed with meconium. MSAF leads to a serious maternal complication that increases the likelihood of operative delivery and poses a hazard to the fetus or the neonate. This in turn enhances the chances of maternal and neonatal mortality and morbidity. So, the identification of determinants helps to breach this vicious cycle. The current study aimed to assess the determinants of MSAF.

Methods

An institution-based, unmatched case-control study with a sample size of 363 participants (121 cases and 242 controls) was conducted on mothers who gave birth at Hadiya zone public hospitals between March and April 2020. A proportionate distribution was made to each facility depending on the volume of patients, and cases and control mothers were chosen sequentially. The data was gathered through in-person interviews and secondary data extraction. In multivariable logistic regression, variables with (p < 0.25) in bivariate analysis were included. After multivariable logistic regression was finished, statistical significance was declared at (p < 0.05).

Results

A total of 121 cases and 242 controls were included in this study Multivariable logistic regression analysis showed that gestational age ≥ 41 week (AOR = 3.44, 95% CI: 1.02–11.63), premature rupture of membrane (AOR = 3.71, 95% CI: 1.98–6.93) obstructed labor (AOR = 2.90, 95% CI: 1.15–7.33) preeclampsia (AOR = 4.16, 95% CI: 1.29–13.35) and non-reassuring fetal heart rate (AOR = 6.75, 95% CI: 3.45–13.19) were significantly associated with MSAF.

Conclusion

Advanced gestational age, an early membrane rupture, an obstructed labor, preeclampsia, and non-reassuring fetal heart rate all increase the incidence of meconium-stained amniotic fluid in laboring mothers. Making every effort to prevent, identify, and treat those obstetric determinants as early as feasible should be taken into consideration throughout follow-up of pregnancy, labor, and delivery could assist to lower the incidence of MSAF.

Association between postterm pregnancy and adverse growth outcomes in preschool-age children

BACKGROUND

Postterm pregnancy has been associated with higher risk of perinatal mortality and morbidity, but its long-term health effects on offspring are poorly understood.

OBJECTIVES

The aim of the study was to investigate the prospective associations between maternal postterm pregnancy and adverse growth outcomes in children.

METHODS

The Jiaxing Birth Cohort is part of a large population-based health surveillance system in China and recruited pregnant females resident in the Jiaxing area between 1999 and 2013; newborns were followed up for a median duration of 5.8 y until they went to school. Mother-child pairs with maternal gestational information and offspring's anthropometric data at 4-7 y old were included. Postterm pregnancy was defined as maternal gestational age ≥42 and <47 wk, and its associations with offspring obesity, overweight/obesity, and thinness during childhood were determined by using Poisson regression models.

RESULTS

Of the 101,505 included mother-child pairs, 2369 (2.3%) children were born at postterm. Children born at postterm had significantly lower BMI-for-age z score, weight-for-age z score, and height-for-age z score than those born at term; the mean difference (95% CI) was -0.11 (-0.15, -0.06), -0.17 (-0.21, -0.13), and -0.16 (-0.20, -0.12), respectively. When comparing postterm with term pregnancy, the multivariable-adjusted RRs and 95% CIs among preschool-age children were 0.87 (0.68, 1.11) for obesity, 0.82 (0.72, 0.94) for overweight/obesity, and 1.18 (1.09, 1.28) for thinness, respectively. These risk estimates were robust in sensitivity analyses, but were attenuated in several subgroups stratified by age, sex, mode of delivery, and fetal distress.

CONCLUSIONS

Postterm pregnancy was associated with a higher risk of thinness, and a lower risk of overweight/obesity, as well as lower growth parameters in preschool-age children. These findings imply that postterm pregnancy may impede the long-term growth of offspring.

Parity status and the relationship between antenatal rubella serology with obstetric outcome

Routine antenatal rubella serological testing is adopted in many countries. In a population covered by universal childhood rubella immunization for four decades, we have observed an association between pre-eclampsia with maternal rubella seronegativity among multiparous gravidae. This retrospective cohort study was further performed to elucidate the interaction between parity status and rubella seronegativity on obstetric outcome in singleton pregnancies carried to ≥ 24 weeks gestation managed from 1997 to 2019, with the data retrieved from a computerized database used for annual statistics and auditing. Of the 133,926 singleton pregnancies eligible for the study, the 13,320 (9.9%) rubella seronegative gravidae had higher mean booking weight and body mass index (BMI), but shorter height, and higher incidence of advanced age (≥ 35 years), high BMI, short stature, and lower incidence of nulliparas. Univariate analysis showed that adverse obstetric outcomes were more frequently found among the multiparas. On multivariate analysis, there was increased postdated (> 41 weeks) pregnancy irrespective of parity status, while nulliparas had reduced gestational hypertension (aRR 0.714, 95% CI 0.567-0.899) and gestational diabetes (aRR 0.850, 95% CI 0.762-0.950), and multiparas had increased pre-eclampsia (aRR 1.261, 95% CI 1.005-1.582), neonatal death (aRR 2.796, 95% CI 1.243-6.291), and perinatal death (aRR 2.123, 95% CI 1.257-3.587). In conclusion, in a population covered by universal childhood rubella immunization, antenatal rubella seronegativity is associated with increased pre-eclampsia and perinatal loss only in multiparas, suggesting that the rubella seronegativity in these women served as proxy for some form of altered immune response which increases adverse pregnancy outcome.

Increased Placental Cell Senescence and Oxidative Stress in Women with Pre-Eclampsia and Normotensive Post-Term Pregnancies

Up to 11% of pregnancies extend to post-term with adverse obstetric events linked to pregnancies over 42 weeks. Oxidative stress and senescence (cells stop growing and dividing by irreversibly arresting their cell cycle and gradually ageing) can result in diminished cell function. There are no detailed studies of placental cell senescence markers across a range of gestational ages, although increased levels have been linked to pre-eclampsia before full term. This study aimed to determine placental senescence and oxidative markers across a range of gestational ages in women with uncomplicated pregnancies and those with a diagnosis of pre-eclampsia. Placentae were obtained from 37 women with uncomplicated pregnancies of 37-42 weeks and from 13 cases of pre-eclampsia of 31+2-41+2 weeks. The expression of markers of senescence, oxidative stress, and antioxidant defence (tumour suppressor protein p16INK4a, kinase inhibitor p21, interleukin-6 (IL-6), NADPH oxidase 4 (NOX4), glutathione peroxidases 1, 3, and 4 (GPx1, GPx3, and GPx4), placental growth factor (PlGF), and soluble fms-like tyrosine kinase-1 (sFlt-1)) genes was measured (quantitative real-time PCR). Protein abundance of p16INK4a, IL-6, NOX4, 8-hydroxy-2'-deoxy-guanosine (8-OHdG), and PlGF was assessed by immunocytochemistry. Placental NOX4 protein was higher in post-term than term deliveries and further increased by pre-eclampsia (p < 0.05 for all). P21 expression was higher in post-term placentae (p = 0.012) and in pre-eclampsia (p = 0.04), compared to term. Placental P16INK4a protein expression was increased post-term, compared to term (p = 0.01). In normotensive women, gestational age at delivery was negatively associated with GPx4 and PlGF (mRNA and protein) (p < 0.05 for all), whereas a positive correlation was seen with placental P21, NOX4, and P16INK4a (p < 0.05 for all) expression. Markers of placental oxidative stress and senescence appear to increase as gestational age increases, with antioxidant defences diminishing concomitantly. These observations increase our understanding of placental health and may contribute to assessment of the optimal gestational age for delivery.

Circulating angiogenic profiles and histo-morphological placental characteristics of uncomplicated post-date pregnancies

INTRODUCTION

The objectives of this study were to describe the histo-morphology of post-date placentas in clinically uncomplicated pregnancies without adverse delivery outcomes and the association with maternal circulating pre-delivery Placental Growth Factor (PlGF) and soluble fms-like tyrosine kinase-1 (sFlt-1), as well as the sFlt-1/PlGF ratio.

METHODS

Post-date placentas (gestational week ≥40⁺², n = 87) were macroscopically and histo-morphologically assessed according to the international, standardized Amsterdam Workshop Consensus Group criteria. Inter-rater agreement was evaluated by percentage of agreement. PlGF and sFlt-1 concentrations were available from maternal serum sampled close to delivery, and were compared by Mann-Whitney U test. Linear regression analyses were adjusted for predefined potential confounders.

RESULTS

The majority of the post-date placentas showed morphological signs of delayed maturation. About half of the placentas showed increased syncytial knotting and fibrin. In placentas with increased presence of intervillous fibrin, median maternal PlGF level was significantly lower (p = 0.004), median sFlt-1 level higher and sFlt-1/PlGF ratio significantly higher (p = 0.002) compared to those with normal fibrin amounts. Increased placental syncytial knotting was associated with lower levels of PlGF, higher sFlt-1 and higher sFlt-1/PlGF ratio compared to those with normal knotting.

DISCUSSION

Our standardized morphological study of post-date placentas in clinically healthy women with uncomplicated pregnancies and delivery outcomes revealed delayed maturation in the majority of placentas. Increased pre-delivery circulating anti-angiogenic profile was associated with increased intervillous fibrin and syncytial knotting. We propose that circulating maternal angiogenic biomarkers may be of future use in clinical post-date pregnancy assessment, as they reflect important aspects of placental health and function.

Stability of Executive Functioning of Moderately-Late Preterm and Full-Term Born Children at Ages 11 and 19: The TRAILS Cohort Study

Moderately-late preterm-born children (MLPs, 32-36 weeks gestational age, GA) have poorer executive functioning (EF) at primary school age than full-term children (FTs). Evidence is lacking on their EF in adolescence, but for early preterm-born children, this has been shown to be much poorer. We, therefore, compared EF of MLPs and FTs at ages 11 and 19 and assessed development between these ages. We obtained data from TRAILS, a community-based prospective cohort study in the northern Netherlands, on 98 MLPs and 1832 FTs. We assessed EF by the Amsterdam Neuropsychological Tasks (ANT) at ages 11 and 19 years and computed gender-specific z-scores on reaction time and accuracy. We compared baseline speed, pattern search, working memory, sustained attention, inhibition, and attentional flexibility of MLPs and FTs crude, and adjusted for small-for-GA status, socioeconomic status, and estimated intelligence. MLPs and FTs performed similarly on all EF components at ages 11 and 19, except for the speed, but not the accuracy measure of attentional flexibility. This was slightly poorer for MLPs than FTs at age 19 (adjusted B 0.25; 95% confidence interval: 0.00 to 0.50; p = 0.047), but not at age 11 (adjusted B -0.02; -0.19 to 0.22; p = 0.87). Differences in EF between MLPs and FTs did not change significantly from age 11 to 19. MLPs had comparable EF on most components as FTs, with only attentional flexibility at age 19 developing slightly poorer for MLPs than for FTs. These findings suggest the effects of MLP birth on long-term EF to be small.

Exercise capacity and cardiac function in adolescents born post-term

There is some evidence that children born post-term (≥42 weeks of gestation) have metabolic abnormalities that may be associated with an increased risk of adverse health outcomes in adulthood. However, there are no data as to whether adolescents born post-term display alterations in aerobic capacity or cardiovascular function. We studied 48 adolescents (56% males) in Auckland (New Zealand) with a mean age of 14.3 years (SD = 1.7): 25 born post-term and 23 born at term (37-41 weeks of gestation). Assessments included metabolic markers in blood, whole body DXA scans, 24-hour ambulatory blood pressure monitoring, maximal exercise capacity, as well as cardiac MRI scan at rest and during submaximal exercise. Exercise capacity was lower in the post-term than in control participants (44.5 vs 47.8 ml/kgffm/min; p = 0.04). There were no differences in left ventricular volumes at rest and during exercise between groups. The 24-hour ambulatory blood pressure monitoring also showed no differences between the two groups. Being born post-term was associated with reduced exercise capacity, but with no observed differences in central cardiac function. We speculate that the reduction in exercise capacity may be due to changes in the peripheral vascular system.

Body Mass Index, Overweight, and Obesity in Swedish Women Born Post-term

BACKGROUND

There is increasing evidence that post-term birth (≥42 weeks of gestation) is associated with adverse long-term outcomes. We assessed whether women born post-term displayed increased risk of overweight and obesity in adulthood.

METHODS

Data were collected at first antenatal visit (~10-12 weeks of gestation) on singleton Swedish women aged ≥18 years in 1991-2009 (mean age 26.1 years), who were born post-term (n = 27 153) or at term (37-41 weeks of gestation; n = 184 245). Study outcomes were evaluated for continuous associations with gestational age. Stratified analyses were carried out comparing women born post-term or at term. Analyses were also run with a 2-week buffer between groups to account for possible errors in gestational age estimation, comparing women born very post-term (≥43 weeks of gestation; n = 5761) to those born within a narrower term window (38-40 weeks of gestation; n = 130 110).

RESULTS

Increasing gestational age was associated with greater adult weight and body mass index (BMI). Stratified analyses showed that women born post-term were 0.5 kg heavier and had BMI 0.2 kg/m(2) greater than those born at term. Differences were more marked between women born very post-term (≥43 weeks) vs. a narrower term group (38-40 weeks): 1.0 kg and 0.3 kg/m(2) . The adjusted relative risks of overweight/obesity and obesity in women born very post-term were 1.13 and 1.12 times higher, respectively, than in those born at term.

CONCLUSIONS

Post-term birth is associated with greater BMI and increased risk of overweight and obesity in adulthood, particularly among women born ≥43 weeks of gestation.

Preterm birth and behavioural outcomes at 8 years of age: a nationwide survey in Japan

OBJECTIVE

To analyse the effect of different preterm birth categories on behavioural outcomes.

DESIGN

Prospective cohort design.

SETTINGS

The Japanese Longitudinal Survey of Babies in the 21st Century was used for the study.

SUBJECTS

Neonates born in 2001 in Japan (n=34,163) and followed up at the age of 8 years. Post-term births were excluded and the sample was divided into four groups according to gestational age: <34 weeks, 34-36 weeks, 37-38 weeks and 39-41 weeks.

OUTCOME MEASURES

Seven behavioural outcomes were examined: three attention problems and four delinquent/aggressive behaviours.

RESULTS

Logistic regression was used to estimate adjusted ORs and 95% CIs for each outcome. Positive associations were found between preterm birth (<37 weeks) and adverse behavioural outcomes compared with full-term birth (39-41 weeks). For attention problems, the OR for 'inability to wait his/her turn' was increased by 1.72 (95% CI 1.22 to 2.43) for gestational age <34 weeks and by 1.28 (95% CI 1.03 to 1.59) for 34-36 weeks' gestation. For delinquent/aggressive behaviour, the OR for the outcome 'destroying books/toys' was increased by 1.46 (95% CI 1.07 to 1.99) for gestational age <34 weeks, while the outcome 'disturbance in public' was increased by 1.20 (95% CI 1.04 to 1.38) for 34-36 weeks' gestation.

CONCLUSIONS

Children who are born <34 weeks, but also between 34 and 36 weeks, are at increased risk of behavioural problems related to attention and delinquent/aggressive behaviour when 8 years old.