Typically flu vaccination rates among pregnant women have hovered between 13 to 18 percent nationally. But a push by health officials during the 2009 season drove vaccination rates for the H1N1 vaccine up to about 45 percent in the United States, where they have remained since.

Some expectant mothers have been reluctant to get a flu shot over concern about the health of the fetus, but the study showed that flu vaccination was not only safe but protective, said Dr. Saad Omer of the Rollins School of Public Health at Emory University, the senior author of the study.

Dr. Omer and his colleagues looked at the electronic medical records of 3,327 pregnant women between April 2009 and April 2010. The study, published in the journal Clinical Infectious Diseases, found that the infants born to vaccinated mothers had a 37 percent lower likelihood of being premature, and they also weighed more at birth than babies born to unvaccinated women.

“There are so many trials where pregnant women are supplemented with omega-3 fatty acids and they’ve all got different results,” said lead study author Jacqueline Gould, a researcher at the Women’s and Children’s Health Research Institute in Adelaide, Australia. “We found that there was neither a positive nor a negative effect on visual or neurological outcomes.”

The Australian team, who published their findings in The American Journal of Clinical Nutrition, analyzed data from 11 clinical trials with a total of 5,272 participants who were randomly assigned to take omega-3 supplements or placebos during the last half of their pregnancies.

Across the trials, the amount of omega-3 taken by the mothers ranged from 240 to 3,300 milligrams per day. And the ages at which children’s brain and vision development were assessed ranged from newborn to 7 years old.

According to the researchers, most of the clinical trials included too few participants to distinguish subtle differences expected from nutritional studies, excluded complicated pregnancies (in which greater differences might have been seen) and didn’t follow the children long enough during development.

“Our analysis highlights that more research is needed,” Gould told Reuters Health.

Omega-3 fatty acids are crucial for healthy fetal brain development and are commonly found in fatty fish such as tuna, mackerel and sardines. Human brains and eyes contain large amounts of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), both forms of omega-3.

Developing fetuses can get DHA from their mothers’ fat stores, and from food and supplements they consume during pregnancy.

Swedish researchers compared 23,498 women who had given birth after I.V.F. from 1990 to 2008 with 116,960 women of the same age and general health who had natural pregnancies. The results appeared online last week in the journal BMJ.

Women with I.V.F. pregnancies had more than four times the risk of venous thrombosis during the first trimester, compared with those with natural pregnancies, and almost seven times the risk of pulmonary embolism. The difference narrowed, but persisted, as the pregnancies progressed.

The I.V.F. procedure induces multiple egg production with high doses of hormones, and the authors suggest that this may be the cause.

“Women who are going to have I.V.F. should know these findings,” said the lead author, Dr. Peter Henriksson, a professor of internal medicine at the Karolinska Institute. “And if they have had blood clots themselves, or have relatives with thrombosis, they should be treated with blood thinners.”

With the exception of two women in lab coats and a buzzing console next to the chaise lounge, [Kimberly and Jonathon] Enderles’ party was like any other family gathering. Drinks, snacks, friendly banter. Once the machine was ready, though, Kimberly asked husband Jonathon to corral the guests around the two monitors and hit the lights.

Suddenly there was a baby on the screen.

The techs pointed out various body parts while family members speculated on the origins of nose and cheek genes. There was cooing, commentary, and from the 3-year-old big brother-to-be, brutal honesty.

“Looks like a monster,” he said. “I like monsters!”

Licensed ultrasound techs Teena Gold and Christy Foster, both members of the American Registry for Diagnostic Medical Sonography, perform 3D/4D ultrasound weeknights and Saturdays around northwest Arkansas. The pair founded Baby Face and More as soon as they could afford a high-quality mobile ultrasound machine of their own. Now they charge $100-$350 to help parents indulge their craving for another glimpse of baby. Guests optional.

“Gender reveal is probably the bulk of our work,” Gold said, referring to parties where parents and guests find out the gender of the unborn baby together in real time.

The Enderles weren’t going for a dramatic moment; they already knew they were expecting a boy. This party was about getting a longer, less-hurried look.

“It’s more of an experience and less of an in-and-out procedure,” said Gold, pointing out that medical ultrasound often does not allow parents to savor the wonder of the life growing inside them.

“This way gets you out of that clinic setting,” added Foster.

Whatever the parents’ motivation, the ultrasound  party trend appears to be spreading. From California to Florida, services like Peek a View and Miracles Imaging help expectant parents turn a procedure into a party.

But not everyone thinks taking ultrasound home is a good idea.

“It’s exciting to share the experience of finding out the gender of your baby with your loved ones,” said Dr. Amber Sills, an OB/GYN from Bentonville, Ark.

But there can be frightening risks, as well.

“What if the ultrasonographer started the ultrasound and there was no heartbeat?” she asked. “Or what if the fetus had not developed a skull/head/brain? This happens more than most people realize. What do you do then?”

Sills points out that ultrasounds have traditionally been used to diagnose chromosomal disorders, malformations, and to aid in estimating fetal weight or the amount of amniotic fluid — not for entertainment value.

“Revealing gender has never been a reason to do an ultrasound,” she said.

“The program, which was started in upstate New York in the 1970s and has been adopted in 42 states, is one of the rare public initiatives that have shown consistent and rigorously tested benefits for the mothers and children, as well as significant savings for taxpayers.

In different studies on different demographic groups, women in the program have had fewer premature deliveries, smoked less during pregnancy, spent less time on public assistance, waited longer to have subsequent children, had fewer arrests and convictions, and maintained longer contact with their baby’s fathers. Their children have had fewer language delays and reported less abuse and neglect, slightly higher I.Q. scores, fewer arrests and convictions by age 19, and less depression and anxiety.

A 2011 study of New York City’s Nurse-Family Partnership program, which currently has 91 nurses serving 1,940 families, projected that by the time a child in the program turns 12, the city, state and federal governments will have saved a combined $27,895, with additional savings thereafter — more than twice the program’s cost per child. The study was conducted by the Pacific Institute for Research and Evaluation using data from the Nurse-Family Partnership’s research at three locations, then extrapolated to New York.

This fall, I attended a dozen home visits, all in the Bronx, with five nurses — three from the Visiting Nurse Service of New York, which contracts with the city to provide service in the Bronx, and two, including Ms. Schmidt, with the health department’s Targeted Citywide Initiative, which tackles the most at-risk cases. The nurses’ styles and backgrounds varied; the families’ needs and challenges even more so. Each mother participated voluntarily and at no cost.

The problems were many: violence on the street, abuse in the women’s past, illness, anger, obesity, insecure housing or financial circumstances. Most of the women had the poor luck to have been born in poverty. Like their middle-class counterparts, none came into the world knowing how to raise a baby.”