Change in paternity and select perinatal outcomes: causal or confounded?

Risk factors for pre-eclampsia in clinical practice guidelines: Comparison with the evidence

OBJECTIVE

To compare pre-eclampsia risk factors identified by clinical practice guidelines (CPGs) with risk factors from hierarchical evidence review, to guide pre-eclampsia prevention.

DESIGN

Our search strategy provided hierarchical evidence of relationships between risk factors and pre-eclampsia using Medline (Ovid), searched from January 2010 to January 2021.

SETTING

Published studies and CPGs.

POPULATION

Pregnant women.

METHODS

We evaluated the strength of association and quality of evidence (GRADE). CPGs (n = 15) were taken from a previous systematic review.

MAIN OUTCOME MEASURE

Pre-eclampsia.

RESULTS

Of 78 pre-eclampsia risk factors, 13 (16.5%) arise only during pregnancy. Strength of association was usually 'probable' (n = 40, 51.3%) and the quality of evidence was low (n = 35, 44.9%). The 'major' and 'moderate' risk factors proposed by 8/15 CPGs were not well aligned with the evidence; of the ten 'major' risk factors (alone warranting aspirin prophylaxis), associations with pre-eclampsia were definite (n = 4), probable (n = 5) or possible (n = 1), based on moderate (n = 4), low (n = 5) or very low (n = 1) quality evidence. Obesity ('moderate' risk factor) was definitely associated with pre-eclampsia (high-quality evidence). The other ten 'moderate' risk factors had probable (n = 8), possible (n = 1) or no (n = 1) association with pre-eclampsia, based on evidence of moderate (n = 1), low (n = 5) or very low (n = 4) quality. Three risk factors not identified by the CPGs had probable associations (high quality): being overweight; 'prehypertension' at booking; and blood pressure of 130-139/80-89 mmHg in early pregnancy.

CONCLUSIONS

Pre-eclampsia risk factors in CPGs are poorly aligned with evidence, particularly for the strongest risk factor of obesity. There is a lack of distinction between risk factors identifiable in early pregnancy and those arising later. A refresh of the strategies advocated by CPGs is needed.

Parental age and preterm birth: a population-based cohort of nearly 3 million California livebirths from 2007 to 2012

PURPOSE

To assess the relationships between parental ages and preterm birth subtypes.

METHODS

A population-based cohort analysis of California livebirths 2007-2012. Associations between maternal and paternal age with spontaneous and medically indicated preterm birth were estimated from Cox proportional hazard models. Parental age was modeled with restricted cubic splines to account for nonlinear relationships.

RESULTS

Young paternal age was associated with increased hazard ratios for spontaneous and medically indicated preterm birth. Older fathers showed elevated hazards for preterm birth in crude analysis but after adjustment the relationship was generally not observed. Aging mothers showed increased hazard ratios for both preterm birth phenotypes.

CONCLUSIONS

After adjusting for parental demographics, births to younger fathers and older mothers had the highest risks for spontaneous preterm birth. The paternal influence on preterm birth was observed to be independent of maternal factors.

Risk factors for preeclampsia and eclampsia at a main referral maternity hospital in Freetown, Sierra Leone: a case-control study

BACKGROUND

In the African region, 5.6% of pregnancies are estimated to be complicated by preeclampsia and 2.9% by eclampsia, with almost one in ten maternal deaths being associated with hypertensive disorders. In Sierra Leone, representing one of the countries with the highest maternal mortality rates in the world, 16% of maternal deaths were caused by pregnancy-induced hypertension in 2016. In the light of the high burden of preeclampsia and eclampsia (PrE/E) in Sierra Leone, we aimed at assessing population-based risk factors for PrE/E to offer improved management for women at risk.

METHODS

A facility-based, unmatched observational case-control study was conducted in Princess Christian Maternity Hospital (PCMH). PCMH is situated in Freetown and is the only health care facility providing 'Comprehensive Emergency Obstetric and Neonatal Care services' throughout the entire country. Cases were defined as pregnant or postpartum women diagnosed with PrE/E, and controls as normotensive postpartum women. Data collection was performed with a questionnaire assessing a wide spectrum of factors influencing pregnant women's health. Statistical analysis was performed by estimating a binary logistic regression model.

RESULTS

We analyzed data of 672 women, 214 cases and 458 controls. The analysis yielded several independent predictors for PrE/E, including family predisposition for PrE/E (AOR = 2.72, 95% CI: 1.46-5.07), preexisting hypertension (AOR = 3.64, 95% CI: 1.32-10.06), a high mid-upper arm circumflex (AOR = 3.09, 95% CI: 1.83-5.22), presence of urinary tract infection during pregnancy (AOR = 2.02, 95% CI: 1.28-3.19), presence of prolonged diarrhoea during pregnancy (AOR = 2.81, 95% CI: 1.63-4.86), low maternal assets (AOR = 2.56, 95% CI: 1.63-4.02), inadequate fruit intake (AOR = 2.58, 95% CI: 1.64-4.06), well or borehole water as the main source of drinking water (AOR = 2.05, 95% CI: 1.31-3.23) and living close to a waste deposit (AOR = 1.94, 95% CI: 1.15-3.25).

CONCLUSION

Our findings suggest that systematic assessment of identified PrE/E risk factors, including a family predisposition for PrE/E, preexisting hypertension, or obesity, should be performed early on in ANC, followed by continued close monitoring of first signs and symptoms of PrE/E. Additionally, counseling on nutrition, exercise, and water safety is needed throughout pregnancy as well as education on improved hygiene behavior. Further research on sources of environmental pollution in Freetown is urgently required.

The mnemonic code of pregnancy: Comparative analyses of pregnancy success and complication risk in first and second human pregnancies

Obstetrical complications such as spontaneous abortion/miscarriage, fetal growth restriction, preeclampsia or preterm birth occur in approx. 15% of human pregnancies. Clinical experts often state that a previous uncomplicated pregnancy reduces the risk for complications in subsequent pregnancies. Vice versa, a prior pregnancy affected by obstetrical complications increases the risk for reoccurrence. However, published evidence directly underpinning these clinical statements is sparse. Considering that the maternal immune adaptation may be causally involved in determining the outcome of subsequent pregnancies, a comprehensive analysis of clinical data was long overdue. We here present a systematic analysis of clinical data using a PubMed-based approach to identify human studies with relevant information on birth weight and incidences of pregnancy complications in first and second pregnancies. From initially 18,592 publications, 37 studies were included in the quantitative data analysis. Women with a previous pregnancy affected by complications where a derailed immune response can be inferred have a 2.2-3.2-fold increased risk to be affected again in a subsequent pregnancy. Conversely, a normally progressing primary pregnancy reduced the risk for complications in a subsequent pregnancy by 35-65%. Moreover, an uncomplicated primary pregnancy was associated with a 4.2% increased birth weight in a following pregnancy without a difference in gestational age at delivery. In conclusion, the increased birth weight after previously uncomplicated pregnancies suggests that an immune memory is mounted during primary pregnancies. This immune memory may promote the successful outcome of subsequent pregnancies or - if missing or compromised - account for a risk perpetuation of pregnancy complications.

Risk of recurrent preterm birth among women according to change in partner

There is well-established literature indicating change in partner as a risk for preeclampsia, yet the research on the risk of preterm birth after a change in partners has been sparse and inconsistent. Using a population of California live born singletons, we aimed to determine the risk of preterm birth after a change in partner between the first and second pregnancies. The risk of preterm and early term delivery in the second pregnancy was calculated for mothers who did or did not change partners between births with the referent group as women who delivered both pregnancies at term and did not change partners. Adjusted odds ratios (ORs) and their 95% confidence intervals (CIs) were calculated. Relative to women who delivered at 39 weeks or later in the second pregnancy and did not change partners, preterm birth risks were somewhat lower for women who changed partners between the first and second pregnancies compared to those women who did not change partners. For example, 10.6% of women who did not change partners and delivered their second pregnancy before 34 weeks also delivered their first pregnancy before 34 weeks, while 8.5% of women who changed partners delivered before 34 weeks. Findings suggest partner change may alter the risk of preterm birth.

Association between gamete source, exposure and preeclampsia: A review of literature

Preeclampsia complicates 3%-5% of pregnancies and is one of the major causes of maternal morbidity and mortality. The pathologic mechanisms are well described but despite decades of research, the exact etiology of preeclampsia remains poorly understood. For years it was believed that the etiology of preeclampsia was the result of maternal factors, but recent evidence suggests that preeclampsia may be a couple specific disease where the interplay between both female and male factors plays an important role. Recent studies have suggested a complex etiologic mechanism that includes genetic imprinting, immune maladaptation, placental ischemia and generalized endothelial dysfunction. The immunological hypothesis suggests exaggerated maternal response against fetal antigens. While the role of maternal exposure to new paternal antigens in the development of preeclampsia was the initial focus of research in this area, studies examining pregnancy outcomes in pregnancies from donor oocytes provide intriguingly similar findings. The pregnancies that resulted from male or female donor gametes or donor embryos bring new insight into the role of immune response to new antigens in pathogenesis of preeclampsia. The primary goal of the current review is the role of exposure to new gametes on the development of preeclampsia. The objective was therefore to provide a review of current literature on the role of cohabitation length, semen exposure and gamete source in development of preeclampsia.