Is there a link between autism and PCOS?

August 21, 2018

A study that tested the hypothesis that polycystic ovary syndrome (PCOS) is linked with autism may inform new interventions for PCOS and autism. PLUS: Does smoking exposure deter breastfeeding? ALSO: Does race play a role in maternal outcomes for older women?

In a three-pronged study, UK investigators tested the hypothesis that polycystic ovary syndrome (PCOS) is linked with autism because both conditions are associated with elevated prenatal testosterone levels. Their findings, which may help inform new interventions for PCOS and autism, were published in Traditional Psychiatry

The researchers obtained anonymized electronic medical records from the UK-based primary care Clinical Practice Research Datalink (CPRD) database. The population was restricted to females aged 21 years or older at the end of the study period who were registered in the CPRD between January 1, 1990 and December 31, 2014 with at least 3 months of recorded medical history prior to autism diagnosis. 

Three matched case-control studies were conducted to test various aspects of the hypothesis. Study 1 (n=971, controls=4,855) examined risk of PCOS in women with autism compared to those without autism. Study 2 (n=26,263, controls=130,717) examined risk of autism in women with PCOS compared to those without PCOS. Study 3 (n=8,588, controls=41,127) examined risk of autism in first-born children of mothers with PCOS compared to first-born children of mothers without PCOS. 

In Study 1, the authors found that a significantly higher percentage of women with autism were diagnosed with PCOS than the controls (2.3% vs 1.1%; unadjusted OR: 2.01, 95% CI 1.22-3.30). In Study 2, autism was almost two times more prevalent in PCOS cases than in controls (0.10% vs 0.05%; unadjusted OR: 2.01, 95% CI 1.26-3.20). In Study 3, mothers with PCOS had higher odds of having a child with autism than the controls (unadjusted OR: 1.60, 95% CI 1.28-2.00).

The authors acknowledge a few limitations to their study. Only first-born children of women with PCOS were included. Previous studies have shown a decreased prevalence of autism in first-born children which may have led to underestimation of rates of autism in the general public. The researchers also did not control for marital status, alcohol use, specific hormone or infertility treatments, and socioeconomic background, since these data were not recorded in CPRD. The data source also requires continuous registration with GPs, which may have limited the availability of children for follow-up autism diagnosis. 

The authors believe that while their findings illustrate an association between PCOS and autism, the chance of having a child with autism is still very rare and should not be overstated. 

 

Does smoking exposure deter breastfeeding?

A prospective study by Chinese investigators shows that having smokers in the household may have a negative impact on a mother’s likelihood of breastfeeding. And the impact may be magnified, depending on how many people in the family smoke.

Published in Breastfeeding Medicine, the results reflect outcomes in 1,240 mother-infant pairs in Hong Kong who were followed up after hospital discharge for 12 months postpartum or until the mothers stopped breastfeeding. The researchers collected demographic data; information on maternal, paternal, and household smoking habits; and data on other potential confounding variables via self-reported questionnaires while the mothers were hospitalized. Women who stopped breastfeeding during the follow-up period were asked to report the total duration (in weeks) of any and exclusive breastfeeding.

All of the infants were born after 37 weeks’ gestation, had Apgar scores of eight or higher at 5 minutes, weighed at least 2,500 g, had no severe medical conditions or congenital malformations, and were not placed in the special care nursery for more than 48 hours after birth or in the intensive care nursery after birth. Confounding variables evaluated by the authors were maternal age, maternal education, household income, length of residence in Hong Kong, return to work postpartum, and partner’s infant feeding preferences. They did not assess for body weight, height, diet, or occupational exposures.

Of the mothers, 2.5% were smokers themselves, 29.2% had partners who smoked, and 11.3% had another smoker living in their home. The authors found that maternal and other family members’ smoking predicted breastfeeding cessation. Mothers exposed to two or more family members who smoked had approximately a 30% higher risk of breastfeeding cessation than the women who had nonsmoking families (adjusted hazard ratio = 1.31; 95% CI 1.01-1.68).

Women who smoked were more likely to be younger and have less education and family income and to be less likely to return to work postpartum. The same characteristics were seen in participants with smoking partners and those partners were more likely to prefer infant formula or mixed feeding for the infant.

The authors noted that their study was not population-based and new mothers with more breastfeeding confidence may have been more likely to participate. The data on smoking status and breastfeeding outcomes also may have been subject to recall bias. The researchers recommended that practitioners “assess the smoking patterns of pregnant women and their family members to provide smoking cessation education and support this high-risk group.”  

Does race play a role in maternal outcomes for older women?

The number of women aged 40 year and older giving birth nearly doubled between 1990 and 2014. Results of a recent retrospective study in Obstetrics & Gynecology show steady increases in maternal morbidity during that period-and race may have played a role in those outcomes.

Using data from the National Inpatient Sample from the Agency for Healthcare Research and Quality for the years 1998 to 2014, the researchers tracked trends in severe maternal morbidity and comorbid risks in women aged 40 to 54. Race and ethnicity were self-reported and were categorized as non-Hispanic white, non-Hispanic black, black, Asian or Pacific Islander, Native American, other, and unknown. ICD-9-CM diagnosis codes were used to identify the trends. The primary outcome of the study was severe maternal morbidity as defined by the Centers for Disease Control and Prevention (21 diagnoses including stroke, shock, and heart failure among others, identified by ICD-9-CM codes). 

The analysis reflected information on more than 1.7 million deliveries by women aged 40 to 54. Births to women in that age group increased over the study period, from 73,946 in 1998 to 110,710 in 2014. Black women had the highest overall risk of severe maternal mortality with unadjusted risk 104% higher than white women (adjusted risk ratio [RR] 2.04, 95% CI 1.98-2.04). Hispanic women (RR 1.28, 95% CI 1.98-2.04), Asian or Pacific Islander women (RR 1.29, 95% CI 1.24-1.34) and Native American women (RR 1.20, 95% CI 1.03-1.39) also were at higher risk than white women. 

Risk of severe morbidity also increased during the study period, from 1.6% in 1998 to 2000 (95% CI 1.5%-1.7%) to 3.0% in 2012 to 2014 (95% CI 2.9-3.1%, < .01). Black women had the greatest risk at the beginning (2.4% in 1998-2000, 95% CI 2.2-2.6%) and the end of the study (4.9% in 2013-2014, 95% CI 4.7-5.1%). 

Overall, there were 231 maternal deaths in the study, including 71 deaths among white women (8.6/100.000, 95% CI 6.9-10.9) 64 among black women (40.5/100,000, 95% CI 31.7-51.7), 48 among Hispanic Women (18.5/100,000, 95% CI 13.9-24.5) and 11 among Asian or Pacific Islander women (11.3/100,000, 95% CI 5.4-17.4). Risk of death was 371% greater for black women than white women (RR 4.71, 95% CI 3.36-6.61) and more than twice as high for Hispanic women (RR 2.13, 95% CI 1.48-3.07) compared to white women. 

Comorbid risk based on medical conditions and other factors increased both overall and individually by race during the period the authors studied. Black women had the absolute highest increase from 1998 to 2003 to 2010 to 2014 in risk for acute renal failure (< .01), disseminated intravascular coagulation (P< .01), transfusion (< .01), and hysterectomy (< .01). 

Rates of pregnancy complications including cesarean delivery, preeclampsia, and gestational diabetes rose for black, white, and Hispanic women. Black women were more likely than non-black women to develop preeclampsia (9.1% vs 5.3%, < .01) and undergo cesarean delivery (50.2% vs 44.8%, < .01). Asian or Pacific Islander and Hispanic women were most likely to develop gestational diabetes and saw the largest absolute increases in risk over the study period (absolute increases of 13.7-22.4% for Asian or Pacific Islander women and 11.2%-19.3% for Hispanic women between 1998 and 2014).

The authors noted a few limitations to their study. Data were missing on race among some of the cohort (labeled as “unknown”) as were data on hospital resources, infrastructure, and staffing. They also could not evaluate outpatient management, coding was unavailable for use of assisted reproductive technology, and condition severity is not specified by diagnosis codes. The researchers said, however, that it is important for obstetricians to recognize disparities between maternal outcomes by race and to treat their patients accordingly, especially black mothers who are at a much higher risk for adverse maternal outcomes. The findings illustrate that an improved understanding of failure to rescue may be vital to reducing these disparities.