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Updated: May 9, 2026
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The Immediate Partial Removal of Cumulus-Oocyte Complexes: A Refined Approach for Rapid Observation of In Vitro Fertilization
Published on: October 18, 2024
Spontaneous conceptions within two years of having a first infant with assisted conception
Karen Wynter1, Catherine McMahon, Karin Hammarberg
1Jean Hailes Research Unit, School of Public Health and Preventive Medicine, Monash University, Melbourne, Victoria, Australia.
Summary
Women who conceived via assisted reproductive technologies (ART) had a 33% spontaneous conception rate for subsequent pregnancies, compared to 40% for those who conceived spontaneously. Contraception counseling is advised for ART conceived first infants if further pregnancies are not desired.
Area of Science:
- Reproductive Medicine
- Obstetrics and Gynecology
- Infertility Studies
Background:
- Limited Australian data exists on spontaneous conceptions after assisted reproductive technologies (ART).
- Understanding subsequent fertility is crucial for family planning post-ART.
Purpose of the Study:
- To determine the incidence of spontaneous conceptions within 18-24 months after a first infant conceived by ART or spontaneously.
- To identify factors associated with spontaneous pregnancies in women with a first ART-conceived infant.
Main Methods:
- Nulliparous women were recruited from ART clinics and maternity hospitals in Australia.
- Interviews were conducted during pregnancy and when the first infant was 18-24 months old.
- Data collected on subsequent pregnancies and conception methods.
Main Results:
- Spontaneous conceptions occurred in 40% of women with a spontaneously conceived first infant and 33% of women with an ART-conceived first infant (without further ART).
- 61% of subsequent pregnancies in the ART group (without further treatment) were unexpected, versus 24% in the spontaneously conceived group.
- Unexplained infertility and shorter partner relationship duration were associated with spontaneous subsequent pregnancies in the ART group.
Conclusions:
- Women with an ART-conceived first infant who do not desire further children or wish to delay pregnancy should discuss contraception.
- Findings highlight the potential for unexpected subsequent spontaneous pregnancies after ART.
Related Concept Videos
01:24In Vitro Fertilization
In vitro fertilization (IVF) is a form of assisted reproductive technology where an egg is fertilized with sperm in a controlled laboratory environment before transferring the resulting embryo into the uterus. This process is designed to help individuals and couples experiencing difficulties conceiving.
The IVF process begins with ovarian stimulation, during which reproductive endocrinologists prescribe hormonal medications to stimulate the ovaries to produce multiple eggs instead of the single...
The IVF process begins with ovarian stimulation, during which reproductive endocrinologists prescribe hormonal medications to stimulate the ovaries to produce multiple eggs instead of the single...
01:38Fertilization
During fertilization, an egg and sperm cell fuse to create a new diploid structure. In humans, the process occurs once the egg has been released from the ovary, and travels into the fallopian tubes. The process requires several key steps: 1) sperm present in the genital tract must locate the egg; 2) once there, sperm need to release enzymes to help them burrow through the protective zona pellucida of the egg; and 3) the membranes of a single sperm cell and egg must fuse, with the sperm...
01:57Meiosis II
Meiosis II is the second and final stage of meiosis. It relies on the haploid cells produced during meiosis I, each of which contain only 23 chromosomes—one from each homologous initial pair. Importantly, each chromosome in these cells is composed of two joined copies, and when these cells enter meiosis II, the goal is to separate such sister chromatids using the same microtubule-based network employed in other division processes. The result of meiosis II is two haploid cells, each containing...
01:34Crossing Over
Unlike mitosis, meiosis aims for genetic diversity in its creation of haploid gametes. Dividing germ cells first begin this process in prophase I, where each chromosome—replicated in S phase—is now composed of two sister chromatids (identical copies) joined centrally.
The homologous pairs of sister chromosomes—one from the maternal and one from the paternal genome—then begin to align alongside each other lengthwise, matching corresponding DNA positions in a process called synapsis.
In order to...
The homologous pairs of sister chromosomes—one from the maternal and one from the paternal genome—then begin to align alongside each other lengthwise, matching corresponding DNA positions in a process called synapsis.
In order to...
01:30Crossing Over
Crossing over is the exchange of genetic information between homologous chromosomes during prophase I of meiosis I. Genetic recombination gives rise to allelic diversity in the newly formed daughter cells. In humans, crossing over produces genetically distinct haploid egg and sperm cells that undergo fertilization to produce unique offspring. Before cell division starts, the germ cell’s chromosome(s) undergo duplication in the S phase of the cell cycle. As the cells enter prophase I, duplicated...
02:21Spontaneity
A spontaneous process is one that occurs naturally under certain conditions. A nonspontaneous process, on the other hand, will not take place unless it is “driven” by the continual input of energy from an external source. Processes have a natural tendency to occur in one direction under a given set of conditions. Water will naturally flow downhill (spontaneous process), but uphill flow (nonspontaneous process) requires outside intervention such as the use of a pump. Iron exposed to the earth’s...