Birth complications more likely in assisted reproduction babies

02 May 2014
3 min read
Volume 22 · Issue 5

Abstract

Research in Australia has found that still births, preterm births, and low birth weight babies are more likely in assisted reproduction pregnancies.

Australia

Australian researchers have found that birth complications are higher among babies conceived by assisted reproductive therapies than those conceived naturally.

The risk of complications such as stillbirth, preterm birth, low birth weight and neonatal death is about twice as high for babies conceived with treatment such as in vitro fertilisation (IVF), intracytoplasmic sperm injection (ICSI), ovulation induction and cryopreservation of embryos.

Researchers from the University of Adelaide's Robinson Institute compared the outcomes of more than 300 000 births in South Australia over a 17-year period, including more than 4300 births from assisted reproduction.

‘Compared with spontaneous conceptions in couples with no record of infertility, singleton babies from assisted conception were almost twice as likely to be stillborn, more than twice as likely to be preterm, almost three times as likely to have very low birth weight, and twice as likely to die within the first 28 days of birth,’ says Professor Michael Davies from the University of Adelaide's Robinson Institute.

He said the outcomes varied depending on the type of assisted conception used. Very low and low birth weight, very preterm and preterm birth, and neonatal death were markedly more common in births from IVF and, to a lesser degree, in births from ICSI.

‘Using frozen embryos eliminated all significant adverse outcomes associated with ICSI but not with IVF. However, frozen embryos were also associated with increased risk of macrosomia (big baby syndrome) for IVF and ICSI babies.’

He called for more research to be done, and that his research needed to be expanded to include more recent years of treatment, to recognise the innovation that has continued with this technology, which may influence the associated risks.

‘If we think that certain bacteria are associated with premature rupturing of the membranes, we can screen for this bacteria early in pregnancy. We then might be able to treat affected women with antibiotics and reduce their risk for PPROM’

This was the first study to compare pregnancies in women diagnosed with infertility, but who never received intensive treatment. ‘Women in this group who eventually conceived without the help of invasive assisted reproduction gave birth to babies who were nine times more likely to have very low birth weight, seven times more likely to be very preterm, and almost seven times more likely to die within the first 28 days of birth. This may be due to the underlying medical conditions related to their infertility, or the use of fertility medications or therapies that are not recorded,’ Professor Davies says.

US

The presence of bacteria in the amniotic fluid may cause a woman's waters to break early according to research from the US.

High levels of bacteria may be a cause, or a consequence, of the thinning of the fetal membranes, resulting in rupture. The fetal membrane is composed of two cell layers, the amnion and chorion. Nearly one-third of all early deliveries are associated with the water breaking in preterm premature rupture of membranes (PPROM).

‘Complications of preterm births can have long-term health effects for both mothers and children. Our research focuses on why the fetal membranes, or water sac, break early in some women, with the overall goal of better understanding the mechanisms of preterm membrane rupture,’ says lead author Amy Murtha, MD, associate professor of obstetrics and gynaecology at Duke University School of Medicine.

In the study, researchers prospectively examined chorion membrane samples to identify a pattern of bacterial presence and association with chorion thinning. They collected membrane samples from a 48 women—including PPROM, preterm and term patients—after they gave birth. They measured chorion thinning and bacterial presence in membrane samples collected from both near and far from the rupture site. In all women, the chorion membrane was thinner at the rupture site than at the distant site. However, chorion thinning was greatest among PPROM patients and was not isolated to the rupture site, as the researchers observed a global chorion thinning even distant from where the membrane ruptured.

‘We still know little about changes occurring within the fetal membrane in the presence of bacteria, but our data suggests the chorion and its thinning may be the battleground for these changes. If we think that certain bacteria are associated with premature rupturing of the membranes, we can screen for this bacteria early in pregnancy. We then might be able to treat affected women with antibiotics and reduce their risk for PPROM,’ says Murtha.