A quarter of stillbirths are preventable by increased obstetric surveillance

Placental insufficiency was identified as the lead cause of potentially preventable stillbirths, followed by medical complications of pregnancy and hypertensive disorders of pregnancy, reported the result of a small study conducted by Jessica M. Page, MD, of the University of Utah School of Medicine, and her colleagues. 

The stillbirth rate in the US was 5.96 per 1,000 births in 2013 and has remained stable since the last decade. Although it is much lower than the global rate of 18.4/1,000 births, it is higher than rates in other developed countries.

Currently, Finland has the lowest stillbirth rate of 2 per 1,000 births, while Pakistan has the highest rate of 43.1 per 1,000 births. Other countries with relatively low stillbirth rates included Norway, Denmark, and Singapore. 

The researchers conducted a secondary analysis of 512 stillbirths from the Stillbirth Collaborative Research Network with post-mortem data and placental histopathology. They identified 114 (22.3%) that were potentially preventable; 27 of those were included in more than one category, of which 23 fit into two categories and 4 fits into three categories.

In fact, one-third of stillbirths due to placental insufficiency had another cause identified as well. When the stillbirths due to placental insufficiency were analyzed further, it was seen that they increased with increasing gestational age, the most common window being after 37 weeks of gestation. The stillbirths due to other causes (potentially preventable and nonpreventable) did not increase with increasing gestational age.

But, the researchers did notice a significant increase in the proportion of potentially preventable stillbirths with increasing gestational age (P=.023). Notably, 39 out of 114 preventable stillbirths occurred after 37 weeks of gestation, when the risk of prematurity was at its minimal, had they been detected at risk of intrauterine death (IUD) and delivered.

When the researchers looked at the role played by race and ethnicity, they did not find any significant difference between various cohorts.

The majority of stillbirths in low resource setting can be preventable, while there is no clue regarding how to bring down the stillbirth rate in developed countries. There are few risk factors that increase the risk of stillbirths like smoking, obesity, advanced maternal age, and multiple gestations but it is not known that how far the risk can be lowered by modification of these factors.

Researchers are optimistic to get some clue regarding prediction of third-trimester stillbirths from data obtained from the Eunice Kennedy Shriver National Institute of Child Health and Human Development–sponsored Human Placenta Project.

The study has many limitations, but it also did include a large number of well-characterized stillbirths from racially, ethnic and geographically diverse population.

This study underscores the importance of close obstetric surveillance with nearly 25% of stillbirths deemed potentially preventable.

The study was published in February 2018 issue of Journal of Obstetrics and Gynecology and also presented as a poster at the Society for Maternal-Fetal Medicine’s 36th Annual Pregnancy Meeting, February 1–6, 2016, Atlanta, Georgia.

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Hypertension in pregnancy nearly doubles the risk autism spectrum disorder and intellectual disability.

A recent study presented at the International Meeting of Autism Research (IMFAR) 2016 shows a significant association between any form of hypertension during pregnancy, particularly in the presence of placental insufficiency and the risk of developing ASD in the offspring.

"Children born to women with preeclampsia, or placental insufficiency, or both are at risk for adverse neurodevelopmental outcomes, including intellectual disability and autism," principal investigator Cheryl Walker, MD, MIND Institute, University of California, Davis, in Sacramento told news media.

"Identification of these children might facilitate very early interventions and improved developmental outcomes at a time when the brain is most responsive to modification," she added.

The current research is an extension of Childhood Autism Risk from Genetics and Environment (CHARGE) study published in Published in JAMA Pediatrics in 2014.

Results of the CHARGE study shows that children who were diagnosed with ASD were twice as likely to be exposed to preeclampsia as compared to controls who showed a typical development(TD).

In the current study also conducted at University of California, Davis, the researchers Paula Krakowiak, PhD and her colleagues decided to dig deeper and study the effects of specific categories of hypertension with and without the presence of placental insufficiency.

The study subjects were drawn from large cohorts of children born in California from 1991 to 2008.

The different types of hypertension studied were chronic hypertension, preeclampsia, and hypertension superimposed on preeclampsia. Presence of Placental insufficiency was determined by signs of intrauterine growth restriction, inadequate amniotic fluid, and small-for-gestational-age birthweight.

Dr Krakowiak opined "Women with any type of hypertensive disorder had approximately a 20% increased risk for having a child with autism relative to the general population." While placental insufficiency alone was modestly associated with ASD risk.

In contrast, women with placental insufficiency and any type of preeclampsia or chronic hypertension has almost 40% increased risks of having a child with ASD.

Association were stronger between intellectual disabilities and preeclampsia. Women had twofold the risk of bearing a child with intellectual disability if she has hypertension and superimposed preeclampsia and the risk rises to threefold in placental insufficiency alone.

Dr Krakowiak observed that the association between hypertensive disorders and intellectual disability was stronger than that for ASD, noting that there is overlap between autism and intellectual disability in real life.

"Many children with autism have varying levels of cognitive impairments, and some children with intellectual disability have mild behavioral symptoms reminiscent of autistic features," she said.

It is postulated that the developing fetus falls short on oxygen and other nutrients in an environment complicated by placental insufficiency and inflammation leading to poor neurodevelopmental outcomes.  

Dr Cheryl Walker advises women to maintain a healthy weight and daily physical activity to improve placental function. Maternal supplementation with low dose aspirin and statins, have shown some promising results in recent studies in diminishing the cellular and end organ damage due to placental insufficiency probably due to improving perfusion.

References:

http://archpedi.jamanetwork.com/article.aspx?articleid=2020784

https://imfar.confex.com/imfar/2016/webprogram/Paper23118.html