Navigation Links
Sex of Twins May Affect Outcomes

Early birth, breathing problems more likely when pair includes a boy, study finds

WEDNESDAY, Oct. 21 (HealthDay News) -- The outcomes of a twin pregnancy -- including the infants' size and delivery date -- might be affected by whether a woman is carrying boys or girls.

Sharing the womb with a female produces better results, in terms of birth weight and other factors, than sharing it with a male, whether the other twin is male or female, according to researchers from the Helen Schneider Hospital for Women and the Sackler School of Medicine at Tel Aviv University in Israel.

"A male fetus affects his co-twin negatively, probably due to the interfetal transport of substances, mainly hormones," said Dr. Marek Glezerman, a university professor and chairman of the hospital's obstetrics and gynecology department and a co-author of the study.

But a U.S.-based expert who reviewed the study calls it interesting but no cause to change the way pregnant women are followed during their pregnancies, regardless of whether they are carrying two girls, two boys or one of each.

"I don't think it translates to changes in clinical practice," said Dr. Steven Ory, a past president of the American Society for Reproductive Medicine and a fertility specialist in Margate, Fla.

The study is published in the November issue of Obstetrics & Gynecology.

The researchers evaluated 2,704 twin pregnancies, looking only at twins within separate placentas born from 1995 through 2006. Previous studies had not differentiated between twins with common or separate placentas, Glezerman said, and this could have blurred the effect of the fetus's sex on the outcome of the pregnancies.

About 16 percent of the pregnancies involved female-female twins, 70 percent were male-female and 14 percent were male-male.

Preterm deliveries were most common among women carrying male-male twins, the study found. Of the male-male twins, 9.2 percent were delivered at less than 31 weeks, compared with 7.5 percent of the male-female twins and 5.5 percent of the female-female twins. Earlier studies have found a higher risk for premature delivery for a male fetus compared with a female.

In the new study, birth weight was higher, on average, for boys than girls: 4.95 pounds, compared with 4.75. But boys in the boy-boy pairs had lower average birth weights than boys in the boy-girl pairs: 4.85 pounds versus 4.99. Boys in the boy-boy pairs also had lower growth rates than boys in boy-girl pairs.

Girls in the girl-girl pairs had fewer respiratory and neurological problems than those in the girl-boy pairs.

The researchers attribute the findings to what they call a "male offending factor," which means that the presence of a male fetus negatively affects the prospects of the co-twin in the womb, whether that co-twin is a sister or a brother.

However, the reasons for this aren't clear. The researchers speculate that one possibility is that male fetuses who share the womb with females could be more successful in competing for nutrients because females tend to grow more slowly. As a result, a boy in a boy-girl pair might end up weighing more than one in a boy-boy pair. Hormonal influences might help explain the differences, too.

None of this should worry expectant mothers, says another U.S. expert.

"Look at this study with a grain of salt and move on," said Dr. Abdulla Al-Khan, director of perinatal diagnostics and therapeutics in the maternal-fetal medicine division at Hackensack University Medical Center in New Jersey. The study's findings have not been noticeable, he said, at his hospital. They deliver more than 6,000 babies a year, including twins, he said, and women carrying twins are already followed closely to monitor the babies' progress.

Both Al-Khan and Ory also pointed out some of the study's limitations. It is retrospective, looking back, which they said makes it subject to bias. And, Al-Khan said, it's not clear whether the twins were conceived spontaneously or through fertility treatments, which might have affected the results.

More information

The American Academy of Pediatrics has more about twins.

SOURCES: Marek Glezerman, M.D., professor, Sackler Medical School, Tel Aviv University, and chairman, department of gynecology, Helen Schneider Hospital for Women, Rabin Medical Center, Tel Aviv, Israel; Steven Ory, M.D., fertility specialist, Margate, Fla.; Abdulla Al-Khan, M.D., director, perinatal diagnostics and therapeutics, division of maternal-fetal medicine, department of obstetrics and gynecology, Hackensack University Medical Center, Hackensack, N.J.; November 2009, Obstetrics & Gynecology

Copyright©2009 ScoutNews,LLC.
All rights reserved

Related medicine news :

1. Overweight Twins Battle the Bulge and Gain A New Lease on Life in National Body Challenge: Twins Edition on Discovery Health
2. Twins study shows genetic basis for face and place recognition
3. Congenital heart defects increasing among IVF twins
4. Formerly Conjoined Twins Leave Packard Childrens Hospital; Heading Home to Costa Rica
5. Baby Madness is Sweeping the Nation! Forty Sets of Twins and Triplets Hit the Court in Discovery Healths BABY MADNESS: MULTIPLES
6. Parents of twins report more mental health symptoms than parents of singletons
7. Uterus Size May Predict Risk for Premature Twins After IVF
8. Vaginal/Caesarean combo delivery of twins safe, UT Southwestern-led research finds
9. Twins Pitcher Glen Perkins Kicks Off 7th Anniversary of Fitness Program in MPS
10. Conjoined Twins Separated by Surgical Team at Childrens Hospital of Pittsburgh of UPMC During Complex, 24-Hour Procedure
11. Discover the Deadly Toxic Twins: Hydrogen Cyanide and Carbon Monoxide
Post Your Comments:
(Date:12/1/2015)... , ... December 01, 2015 , ... ... Visage Imaging Inc. (“Visage”), a wholly owned subsidiary of Pro Medicus Ltd. (ASX: ... enhancements at the Radiological Society of North America (RSNA) 2015 annual meeting through ...
(Date:12/1/2015)... ... December 01, 2015 , ... TCS Healthcare Technologies (TCS), ... population health arenas, is pleased to announce that VIP Care Services, a Caprock ... implemented the ACUITY Complete Care™ Management to back their collaborative catastrophic case management ...
(Date:12/1/2015)... ... December 01, 2015 , ... Nurotron Biotechnology Co., Ltd., maker of cochlear implant ... , The order will be from the China Disabled Persons’ Federation, a central ... an effective solution for children and adults suffering from severe and profound hearing ...
(Date:11/30/2015)... ... November 30, 2015 , ... ... and Brooke Bennett are collaborating with brands across various categories through traditional and ... figures make up an elite group of Gold Medal Moms who can connect ...
(Date:11/30/2015)... Garden City, NY (PRWEB) , ... December 01, ... ... (NAPW) honors Dale Jones as a 2015-2016 inductee into its ... for leadership in education. NAPW is the nation’s leading networking organization exclusively for ...
Breaking Medicine News(10 mins):
(Date:12/1/2015)... 2015  Today, AmerisourceBergen, a global ... a first-of-its-kind population health management program focused on ... to be built into existing employer benefit packages, ... for their care and explains how to avoid ... to help patients understand their treatment options and ...
(Date:12/1/2015)... 1, 2015  The migration to value-based care ... care plans that help patients stay healthy and ... be digitally enabled, incorporate care guidelines and be ... They will also allow all stakeholders to collaborate ... is optimal. That is the vision, however, research ...
(Date:12/1/2015)... WASHINGTON and TELTOW, Germany ... SensoMotoric Instruments (SMI) , a leading global manufacturer of ... RightEye LLC has included SMI remote eye trackers ... that help healthcare providers assess concussions, eye sight, and ... SMI RED -oem technology is part of SMI,s mass-market-ready ...
Breaking Medicine Technology: