When we talk about pregnancy complications and infertility issues, we always tend to think of maternal age. That's not incorrect: Maternal age, especially up to age 35, has been directly linked to increased rates of miscarriage and chromosomal abnormalities.

However, paternal age and sperm abnormalities also may have a significant effect on newborn outcomes, as was recently observed in a study from Johns Hopkins University. The study found that the locations of epigenetic tags, which can be detected in paternal sperm, were statistically related to whether the father's child would show early signs of autism.

Researchers studied biological data from mothers and fathers who already had a child on the autism spectrum, based on previous studies that suggest autism may have a genetic link. They took biological data from the mothers, who were pregnant with another child, as well as from the fathers -- data that included a sperm sample. They then took biological data from their children after they were born. One year after the child's birth, doctors tested them for early signs of autism.

The study authors analyzed 44 fathers' epigenetic tags, which regulate gene activity, and found almost 200 sites where the presence or absence of a tag appeared to predict whether the child showed symptoms of an autism spectrum disorder (ASD). They narrowed that down to 10 different sites which were associated with developmental delays, a characteristic of ASD.

Based on their findings, the study authors argued that testing a father's sperm help predict a child's autism risk.

Now, just like we saw with autism from this recent study, there are diseases and issues with mental illness that have been linked to paternal age and thus sperm quality. Especially for men older than 55, studies have shown a moderate increase in rates of schizophrenia and bipolar disorders in their children.

There are also some genetic diseases that are related to a small number of points of mutation in the sperm, which exclusively come from unaffected fathers.  Those include Apert syndrome, Crouzon syndrome and Pfeiffer syndrome -- all characterized by malformations of the skull and certain bones throughout the body. Other anatomical conditions or malformations that have been associated with sperm abnormalities include some in the extremities of the newborn, heart defects, and of course the classic disease such as hemophilia A, Klinefelter syndrome and Marfan syndrome.

So, you see, as the age of the father increases, there is a correlation in the scientific literature on semen quality and fertility outcomes. It is important to always consider this when it comes to building your family together. Now, most of these conditions can be diagnosed before birth, but remember, it takes two to tango.

Lifestyle is also very important. More and more studies are suggesting that certain lifestyle choices -- like excessive alcohol consumption -- made by fathers could have a detrimental effect on the newborn. Some animal studies have shown that paternal alcohol exposure prior to conception may cause developmental effects in the child. Additionally, excessive use of marijuana has been linked to decreased male fertility.

The post Dr. Manny: Sperm quality's impact on autism risk and other conditions appeared first on Ask Dr Manny.

Dr. Manny Alvarez serves as Fox News Channel's senior managing health editor. He also serves as chairman of the department of obstetrics/gynecology and reproductive science at Hackensack University Medical Center in New Jersey. Click here for more information on Dr. Manny's work with Hackensack University Medical Center. Visit AskDrManny.com for more.